VisualStyleRenderer Třída

Definice

public ref class VisualStyleRenderer sealed

public sealed class VisualStyleRenderer

type VisualStyleRenderer = class

Public NotInheritable Class VisualStyleRenderer

Dědičnost

Object

VisualStyleRenderer

Příklady

Následující příklad kódu používá třídu VisualStyleRenderer k implementaci vlastního ovládacího prvku, který simuluje některé základní uživatelské rozhraní okna, včetně přetažení s záhlavím, změna velikosti pomocí úchytu pro změnu velikosti a zavření. Tento příklad používá několik VisualStyleElement objektů, které představují standardní části okna, včetně prvků vystavených VisualStyleElement.Window.Caption, VisualStyleElement.Window.CloseButtona VisualStyleElement.Status.Gripper třídy.

#using <System.Drawing.dll>
#using <System.Windows.Forms.dll>
#using <System.dll>

using namespace System;
using namespace System::Text;
using namespace System::Drawing;
using namespace System::Drawing::Drawing2D;
using namespace System::Collections::Generic;
using namespace System::Windows::Forms;
using namespace System::Windows::Forms::VisualStyles;

namespace VisualStyleRendererSample
{

    public ref class WindowSimulation : public Control
    {
    private:
        Dictionary<String^, VisualStyleElement^>^ windowElements;
        Dictionary<String^, Rectangle>^ elementRectangles;
        VisualStyleRenderer^ renderer;
        Point closeButtonOffset;
        System::Drawing::Size gripperSize;
        System::Drawing::Size closeButtonSize;
        bool isResizing;
        bool isMoving;
        bool isClosing;
        int captionHeight;
        int frameThickness;
        int statusHeight;
        Point originalClick;
        Point resizeOffset;

    public:
        WindowSimulation() : Control()
        {
            statusHeight = 22;
            windowElements = gcnew Dictionary<String^, VisualStyleElement^>();
            elementRectangles = gcnew Dictionary<String^, Rectangle>();
            this->Location = Point(50, 50);
            this->Size = System::Drawing::Size(350, 300);
            this->BackColor = Color::Azure;
            this->DoubleBuffered = true;
            this->MinimumSize = System::Drawing::Size(300, 200);
            this->Font = SystemFonts::CaptionFont;
            this->Text = "Simulated Window";

            // Insert the VisualStyleElement objects into the Dictionary.
            windowElements->Add("windowCaption",
                VisualStyleElement::Window::Caption::Active);
            windowElements->Add("windowBottom",
                VisualStyleElement::Window::FrameBottom::Active);
            windowElements->Add("windowLeft",
                VisualStyleElement::Window::FrameLeft::Active);
            windowElements->Add("windowRight",
                VisualStyleElement::Window::FrameRight::Active);
            windowElements->Add("windowClose",
                VisualStyleElement::Window::CloseButton::Normal);
            windowElements->Add("statusBar",
                VisualStyleElement::Status::Bar::Normal);
            windowElements->Add("statusGripper",
                VisualStyleElement::Status::Gripper::Normal);

            // Get the sizes and location offsets for the window parts
            // as specified by the visual style, and then use this
            // information to calcualate the rectangles for each part.
            GetPartDetails();
            CalculateRectangles();

            this->MouseDown +=
                gcnew MouseEventHandler(this,
                    &WindowSimulation::ImitationWindow_MouseDown);
            this->MouseUp +=
                gcnew MouseEventHandler(this,
                    &WindowSimulation::ImitationWindow_MouseUp);
            this->MouseMove +=
                gcnew MouseEventHandler(this,
                    &WindowSimulation::ImitationWindow_MouseMove);
        }

        // Get the sizes and offsets for the window parts as specified
        // by the visual style.
    private:
        void GetPartDetails()
        {
            // Do nothing further if visual styles are not enabled.
            if (!Application::RenderWithVisualStyles)
            {
                return;
            }

            Graphics^ g = this->CreateGraphics();

            // Get the size and offset of the close button.
            if (SetRenderer(windowElements["windowClose"]))
            {
                closeButtonSize =
                    renderer->GetPartSize(g, ThemeSizeType::True);
                closeButtonOffset =
                    renderer->GetPoint(PointProperty::Offset);
            }

            // Get the height of the window caption.
            if (SetRenderer(windowElements["windowCaption"]))
            {
                captionHeight = renderer->GetPartSize(g,
                    ThemeSizeType::True).Height;
            }

            // Get the thickness of the left, bottom,
            // and right window frame.
            if (SetRenderer(windowElements["windowLeft"]))
            {
                frameThickness = renderer->GetPartSize(g,
                    ThemeSizeType::True).Width;
            }

            // Get the size of the resizing gripper.
            if (SetRenderer(windowElements["statusGripper"]))
            {
                gripperSize = renderer->GetPartSize(g,
                    ThemeSizeType::True);
            }

        }

        // Use the part metrics to determine the current size
        // of the rectangles for all of the window parts.
    private:
        void CalculateRectangles()
        {
            int heightMinusFrame =
                ClientRectangle.Height - frameThickness;

            // Calculate the window frame rectangles and add them
            // to the Dictionary of rectangles.
            elementRectangles["windowCaption"] = Rectangle(0, 0,
                ClientRectangle.Width, captionHeight);
            elementRectangles["windowBottom"] = Rectangle(0,
                heightMinusFrame, ClientRectangle.Width, frameThickness);
            elementRectangles["windowLeft"] = Rectangle(0, captionHeight,
                frameThickness, heightMinusFrame - captionHeight);
            elementRectangles["windowRight"] = Rectangle(
                ClientRectangle.Width - frameThickness, captionHeight,
                frameThickness, heightMinusFrame - captionHeight);

            // Calculate the window button rectangle and add it
            // to the Dictionary of rectangles.
            elementRectangles["windowClose"] =
                Rectangle(ClientRectangle.Right +
                    closeButtonOffset.X - closeButtonSize.Width - frameThickness, closeButtonOffset.Y,
                    closeButtonSize.Width, closeButtonSize.Height);

            // Calculate the status bar rectangles and add them
            // to the Dictionary of rectangles.
            elementRectangles["statusBar"] =
                Rectangle(frameThickness,
                    heightMinusFrame - statusHeight,
                    ClientRectangle.Width - (2 * frameThickness),
                    statusHeight);
            elementRectangles["statusGripper"] =
                Rectangle(ClientRectangle.Right -
                gripperSize.Width - frameThickness,
                heightMinusFrame - gripperSize.Height,
                gripperSize.Width, gripperSize.Height);
        }

    protected:
        virtual void OnPaint(PaintEventArgs^ e) override
        {
            __super::OnPaint(e);

            // Ensure that visual styles are supported.
            if (!Application::RenderWithVisualStyles)
            {
                this->Text = "Visual styles are not enabled.";
                TextRenderer::DrawText(e->Graphics, this->Text,
                    this->Font, this->Location, this->ForeColor);
                return;
            }

            // Set the clip region to define the curved corners
            // of the caption.
            SetClipRegion();

            // Draw each part of the window.
            for each(KeyValuePair<String^, VisualStyleElement^>^ entry
                in windowElements)
            {
                if (SetRenderer(entry->Value))
                {
                    renderer->DrawBackground(e->Graphics,
                        elementRectangles[entry->Key]);
                }
            }

            // Draw the caption text.
            TextRenderer::DrawText(e->Graphics, this->Text, this->Font,
                elementRectangles["windowCaption"], Color::White,
                TextFormatFlags::VerticalCenter |
                TextFormatFlags::HorizontalCenter);
        }
private:
        // Initiate dragging, resizing, or closing the imitation window.
        void ImitationWindow_MouseDown(Object^ sender, MouseEventArgs^ e)
        {
            // The user clicked the close button.
            if (elementRectangles["windowClose"].Contains(e->Location))
            {
                windowElements["windowClose"] =
                    VisualStyleElement::Window::CloseButton::Pressed;
                isClosing = true;
            }

            // The user clicked the status grip.
            else if (elementRectangles["statusGripper"].Contains(e->Location))
            {
                isResizing = true;
                this->Cursor = Cursors::SizeNWSE;
                resizeOffset.X = this->Right - this->Left - e->X;
                resizeOffset.Y = this->Bottom - this->Top - e->Y;
            }

            // The user clicked the window caption.
            else if (elementRectangles["windowCaption"].Contains(e->Location))
            {
                isMoving = true;
                originalClick.X = e->X;
                originalClick.Y = e->Y;
            }

            Invalidate();
        }

        // Stop any current resizing or moving actions.
        void ImitationWindow_MouseUp(Object^ sender, MouseEventArgs^ e)
        {
            // Stop moving the location of the window rectangles.
            if (isMoving)
            {
                isMoving = false;
            }

            // Change the cursor back to the default if the user
            // stops resizing.
            else if (isResizing)
            {
                isResizing = false;
            }

            // Close the application if the user clicks the
            // close button.
            else if (elementRectangles["windowClose"].Contains(e->Location) 
                && isClosing)
            {
                Application::Exit();
            }
        }

        // Handle resizing or moving actions.
        void ImitationWindow_MouseMove(Object^ sender,
            MouseEventArgs^ e)
        {
            // The left mouse button is down.
            if ((::MouseButtons::Left & e->Button) == ::MouseButtons::Left)
            {
                // Calculate the new control size if the user is
                // dragging the resizing grip.
                if (isResizing)
                {
                    this->Width = e->X + resizeOffset.X;
                    this->Height = e->Y + resizeOffset.Y;
                    CalculateRectangles();
                }

                // Calculate the new location of the control if the
                // user is dragging the window caption.
                else if (isMoving)
                {
                    int XChange = this->Location.X + (e->X - originalClick.X);
                    int YChange = this->Location.Y + (e->Y - originalClick.Y);
                    this->Location = Point(XChange, YChange);
                }

                // Cancel the closing action if the user clicked
                // and held down on the close button, and has dragged
                // the pointer outside the button.
                else if (!elementRectangles["windowClose"].Contains(
                    e->Location) && isClosing)
                {
                    isClosing = false;
                    windowElements["windowClose"] =
                        VisualStyleElement::Window::CloseButton::Normal;
                }
            }

            // The left mouse button is not down.
            else
            {
                // Paint the close button hot if the cursor is on it.
                Rectangle^ closeRectangle =
                    elementRectangles["windowClose"];
                if (closeRectangle->Contains(e->Location))
                {
                    windowElements["windowClose"] =
                        VisualStyleElement::Window::CloseButton::Hot;
                }
                else
                {
                    windowElements["windowClose"] =
                        VisualStyleElement::Window::CloseButton::Normal;
                }


                // Use a resizing cursor if the cursor is on the
                // status grip.
                Rectangle^ gripRectangle = elementRectangles["statusGripper"];
                if (gripRectangle->Contains(e->Location))
                {
                    this->Cursor = Cursors::SizeNWSE;
                }
                else
                {
                    this->Cursor = Cursors::Default;
                }
            }

            Invalidate();
        }

        // Calculate and set the clipping region for the control
        // so that the corners of the title bar are rounded.
    private:
        void SetClipRegion()
        {
            if (!Application::RenderWithVisualStyles)
            {
                return;
            }

            Graphics^ g = this->CreateGraphics();
            // Get the current region for the window caption.
            if (SetRenderer(windowElements["windowCaption"]))
            {
                System::Drawing::Region^ clipRegion =
                    renderer->GetBackgroundRegion(g,
                    elementRectangles["windowCaption"]);

                // Get the client rectangle, but exclude the region
                // of the window caption.
                int height = (int)clipRegion->GetBounds(g).Height;
                System::Drawing::Rectangle nonCaptionRect = Rectangle(
                    ClientRectangle.X, ClientRectangle.Y + height,
                    ClientRectangle.Width, ClientRectangle.Height - height);

                // Add the rectangle to the caption region, and
                // make this region the form's clipping region.
                clipRegion->Union(nonCaptionRect);
                this->Region = clipRegion;
            }

        }

        // Set the VisualStyleRenderer to a new element.
    private:
        bool SetRenderer(VisualStyleElement^ element)
        {
            if (!VisualStyleRenderer::IsElementDefined(element))
            {
                return false;
            }

            if (renderer == nullptr)
            {
                renderer = gcnew VisualStyleRenderer(element);
            }
            else
            {
                renderer->SetParameters(element);
            }

            return true;
        }
    };

    public ref class Form1 : public Form
    {
    public:
        Form1() : Form()
        {
            this->Size = System::Drawing::Size(800, 600);
            this->Location = Point(20, 20);
            this->BackColor = Color::DarkGray;
            WindowSimulation^ ws = gcnew WindowSimulation();
            Controls->Add(ws);
        }

    };
}

[STAThread]
int main()
{
    Application::EnableVisualStyles();
    Application::Run(gcnew VisualStyleRendererSample::Form1());
}

using System;
using System.Text;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Collections.Generic;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;

namespace VisualStyleRendererSample
{
    class Form1 : Form
    {
        public Form1()
            : base()
        {
            this.Size = new Size(800, 600);
            this.Location = new Point(20, 20);
            this.BackColor = Color.DarkGray;
            WindowSimulation Window1 = new WindowSimulation();
            Controls.Add(Window1);
        }

        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.Run(new Form1());
        }
    }

    public class WindowSimulation : Control
    {
        private Dictionary<string, VisualStyleElement> windowElements =
            new Dictionary<string, VisualStyleElement>();
        private Dictionary<string, Rectangle> elementRectangles =
            new Dictionary<string, Rectangle>();
        private VisualStyleRenderer renderer = null;

        private Point closeButtonOffset;
        private Size gripperSize;
        private Size closeButtonSize;
        private bool isResizing = false;
        private bool isMoving = false;
        private bool isClosing = false;
        private int captionHeight;
        private int frameThickness;
        private int statusHeight = 22;
        private Point originalClick = new Point();
        private Point resizeOffset = new Point();

        public WindowSimulation()
            : base()
        {
            this.Location = new Point(50, 50);
            this.Size = new Size(350, 300);
            this.BackColor = Color.Azure;
            this.DoubleBuffered = true;
            this.MinimumSize = new Size(300, 200);
            this.Font = SystemFonts.CaptionFont;
            this.Text = "Simulated Window";

            // Insert the VisualStyleElement objects into the Dictionary.
            windowElements.Add("windowCaption",
                VisualStyleElement.Window.Caption.Active);
            windowElements.Add("windowBottom",
                VisualStyleElement.Window.FrameBottom.Active);
            windowElements.Add("windowLeft",
                VisualStyleElement.Window.FrameLeft.Active);
            windowElements.Add("windowRight",
                VisualStyleElement.Window.FrameRight.Active);
            windowElements.Add("windowClose",
                VisualStyleElement.Window.CloseButton.Normal);
            windowElements.Add("statusBar",
                VisualStyleElement.Status.Bar.Normal);
            windowElements.Add("statusGripper",
                VisualStyleElement.Status.Gripper.Normal);

            // Get the sizes and location offsets for the window parts  
            // as specified by the visual style, and then use this 
            // information to calcualate the rectangles for each part.
            GetPartDetails();
            CalculateRectangles();

            this.MouseDown +=
                new MouseEventHandler(ImitationWindow_MouseDown);
            this.MouseUp +=
                new MouseEventHandler(ImitationWindow_MouseUp);
            this.MouseMove +=
                new MouseEventHandler(ImitationWindow_MouseMove);
        }

        // Get the sizes and offsets for the window parts as specified  
        // by the visual style.
        private void GetPartDetails()
        {
            // Do nothing further if visual styles are not enabled.
            if (!Application.RenderWithVisualStyles)
            {
                return;
            }

            using (Graphics g = this.CreateGraphics())
            {
                // Get the size and offset of the close button.
                if (SetRenderer(windowElements["windowClose"]))
                {
                    closeButtonSize =
                        renderer.GetPartSize(g, ThemeSizeType.True);
                    closeButtonOffset =
                        renderer.GetPoint(PointProperty.Offset);
                }

                // Get the height of the window caption.
                if (SetRenderer(windowElements["windowCaption"]))
                {
                    captionHeight = renderer.GetPartSize(g,
                        ThemeSizeType.True).Height;
                }

                // Get the thickness of the left, bottom, 
                // and right window frame.
                if (SetRenderer(windowElements["windowLeft"]))
                {
                    frameThickness = renderer.GetPartSize(g,
                        ThemeSizeType.True).Width;
                }

                // Get the size of the resizing gripper.
                if (SetRenderer(windowElements["statusGripper"]))
                {
                    gripperSize = renderer.GetPartSize(g,
                        ThemeSizeType.True);
                }
            }
        }

        // Use the part metrics to determine the current size 
        // of the rectangles for all of the window parts.
        private void CalculateRectangles()
        {
            int heightMinusFrame =
                ClientRectangle.Height - frameThickness;

            // Calculate the window frame rectangles and add them
            // to the Dictionary of rectangles.
            elementRectangles["windowCaption"] =
                new Rectangle(0, 0,
                ClientRectangle.Width, captionHeight);
            elementRectangles["windowBottom"] =
                new Rectangle(0, heightMinusFrame,
                ClientRectangle.Width, frameThickness);
            elementRectangles["windowLeft"] =
                new Rectangle(0, captionHeight, frameThickness,
                heightMinusFrame - captionHeight);
            elementRectangles["windowRight"] =
                new Rectangle(ClientRectangle.Width - frameThickness,
                captionHeight, frameThickness,
                heightMinusFrame - captionHeight);

            // Calculate the window button rectangle and add it
            // to the Dictionary of rectangles.
            elementRectangles["windowClose"] =
                new Rectangle(ClientRectangle.Right +
                closeButtonOffset.X - closeButtonSize.Width - frameThickness, closeButtonOffset.Y,
                closeButtonSize.Width, closeButtonSize.Height);

            // Calculate the status bar rectangles and add them
            // to the Dictionary of rectangles.
            elementRectangles["statusBar"] =
                new Rectangle(frameThickness,
                heightMinusFrame - statusHeight,
                ClientRectangle.Width - (2 * frameThickness),
                statusHeight);
            elementRectangles["statusGripper"] =
                new Rectangle(ClientRectangle.Right -
                gripperSize.Width - frameThickness,
                heightMinusFrame - gripperSize.Height,
                gripperSize.Width, gripperSize.Height);
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);

            // Ensure that visual styles are supported.
            if (!Application.RenderWithVisualStyles)
            {
                this.Text = "Visual styles are not enabled.";
                TextRenderer.DrawText(e.Graphics, this.Text,
                    this.Font, this.Location, this.ForeColor);
                return;
            }

            // Set the clip region to define the curved corners 
            // of the caption.
            SetClipRegion();

            // Draw each part of the window.
            foreach (KeyValuePair<string, VisualStyleElement> entry
                in windowElements)
            {
                if (SetRenderer(entry.Value))
                {
                    renderer.DrawBackground(e.Graphics,
                        elementRectangles[entry.Key]);
                }
            }

            // Draw the caption text.
            TextRenderer.DrawText(e.Graphics, this.Text, this.Font,
                elementRectangles["windowCaption"], Color.White,
                TextFormatFlags.VerticalCenter |
                TextFormatFlags.HorizontalCenter);
        }

        // Initiate dragging, resizing, or closing the imitation window.
        void ImitationWindow_MouseDown(object sender, MouseEventArgs e)
        {
            // The user clicked the close button.
            if (elementRectangles["windowClose"].Contains(e.Location))
            {
                windowElements["windowClose"] =
                    VisualStyleElement.Window.CloseButton.Pressed;
                isClosing = true;
            }

            // The user clicked the status grip.
            else if (elementRectangles["statusGripper"].
                Contains(e.Location))
            {
                isResizing = true;
                this.Cursor = Cursors.SizeNWSE;
                resizeOffset.X = this.Right - this.Left - e.X;
                resizeOffset.Y = this.Bottom - this.Top - e.Y;
            }

            // The user clicked the window caption.
            else if (elementRectangles["windowCaption"].
                Contains(e.Location))
            {
                isMoving = true;
                originalClick.X = e.X;
                originalClick.Y = e.Y;
            }

            Invalidate();
        }

        // Stop any current resizing or moving actions.
        void ImitationWindow_MouseUp(object sender, MouseEventArgs e)
        {
            // Stop moving the location of the window rectangles.
            if (isMoving)
            {
                isMoving = false;
            }

            // Change the cursor back to the default if the user 
            // stops resizing.
            else if (isResizing)
            {
                isResizing = false;
            }

            // Close the application if the user clicks the 
            // close button.
            else if (elementRectangles["windowClose"].
                Contains(e.Location) && isClosing)
            {
                Application.Exit();
            }
        }

        // Handle resizing or moving actions.
        void ImitationWindow_MouseMove(object sender,
            MouseEventArgs e)
        {
            // The left mouse button is down.
            if ((MouseButtons.Left & e.Button) == MouseButtons.Left)
            {
                // Calculate the new control size if the user is 
                // dragging the resizing grip.
                if (isResizing)
                {
                    this.Width = e.X + resizeOffset.X;
                    this.Height = e.Y + resizeOffset.Y;
                    CalculateRectangles();
                }

                // Calculate the new location of the control if the  
                // user is dragging the window caption.
                else if (isMoving)
                {
                    int XChange = this.Location.X +
                        (e.X - originalClick.X);
                    int YChange = this.Location.Y +
                        (e.Y - originalClick.Y);
                    this.Location = new Point(XChange, YChange);
                }

                // Cancel the closing action if the user clicked  
                // and held down on the close button, and has dragged   
                // the pointer outside the button.
                else if (!elementRectangles["windowClose"].
                    Contains(e.Location) && isClosing)
                {
                    isClosing = false;
                    windowElements["windowClose"] =
                        VisualStyleElement.Window.CloseButton.Normal;
                }
            }

            // The left mouse button is not down.
            else
            {
                // Paint the close button hot if the cursor is on it.
                Rectangle closeRectangle =
                    elementRectangles["windowClose"];
                windowElements["windowClose"] =
                    closeRectangle.Contains(e.Location) ?
                    VisualStyleElement.Window.CloseButton.Hot :
                    VisualStyleElement.Window.CloseButton.Normal;

                // Use a resizing cursor if the cursor is on the 
                // status grip.
                Rectangle gripRectangle =
                    elementRectangles["statusGripper"];
                this.Cursor = gripRectangle.Contains(e.Location) ?
                    Cursors.SizeNWSE : Cursors.Default;
            }

            Invalidate();
        }

        // Calculate and set the clipping region for the control  
        // so that the corners of the title bar are rounded.
        private void SetClipRegion()
        {
            if (!Application.RenderWithVisualStyles)
            {
                return;
            }

            using (Graphics g = this.CreateGraphics())
            {
                // Get the current region for the window caption.
                if (SetRenderer(windowElements["windowCaption"]))
                {
                    Region clipRegion = renderer.GetBackgroundRegion(
                        g, elementRectangles["windowCaption"]);

                    // Get the client rectangle, but exclude the region 
                    // of the window caption.
                    int height = (int)clipRegion.GetBounds(g).Height;
                    Rectangle nonCaptionRect = new Rectangle(
                        ClientRectangle.X,
                        ClientRectangle.Y + height,
                        ClientRectangle.Width,
                        ClientRectangle.Height - height);

                    // Add the rectangle to the caption region, and  
                    // make this region the form's clipping region.
                    clipRegion.Union(nonCaptionRect);
                    this.Region = clipRegion;
                }
            }
        }

        // Set the VisualStyleRenderer to a new element.
        private bool SetRenderer(VisualStyleElement element)
        {
            if (!VisualStyleRenderer.IsElementDefined(element))
            {
                return false;
            }

            if (renderer == null)
            {
                renderer = new VisualStyleRenderer(element);
            }
            else
            {
                renderer.SetParameters(element);
            }

            return true;
        }
    }
}

Imports System.Text
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Collections.Generic
Imports System.Windows.Forms
Imports System.Windows.Forms.VisualStyles

Namespace VisualStyleRendererSample

    Class Form1
        Inherits Form

        Public Sub New()
            With Me
                .Size = New Size(800, 600)
                .Location = New Point(20, 20)
                .BackColor = Color.DarkGray
            End With
            Dim Window1 As New ImitationWindow()
            Controls.Add(Window1)
        End Sub

        <STAThread()> _
        Shared Sub Main()
            Application.EnableVisualStyles()
            Application.Run(New Form1())
        End Sub
    End Class

    Public Class ImitationWindow
        Inherits Control

        Private windowElements As _
            New Dictionary(Of String, VisualStyleElement)
        Private elementRectangles As _
            New Dictionary(Of String, Rectangle)
        Private renderer As VisualStyleRenderer = Nothing
        Private closeButtonOffset As Point
        Private gripperSize As Size
        Private closeButtonSize As Size
        Private isResizing As Boolean = False
        Private isMoving As Boolean = False
        Private isClosing As Boolean = False
        Private captionHeight As Integer
        Private frameThickness As Integer
        Private statusHeight As Integer = 22
        Private originalClick As New Point()
        Private resizeOffset As New Point()

        Public Sub New()
            With Me
                .Location = New Point(50, 50)
                .Size = New Size(350, 300)
                .BackColor = Color.Azure
                .DoubleBuffered = True
                .MinimumSize = New Size(300, 200)
                .Font = SystemFonts.CaptionFont
                .Text = "Imitation Window"
            End With

            ' Create a collection of VisualStyleElement objects.
            With windowElements
                .Add("windowCaption", _
                    VisualStyleElement.Window.Caption.Active)
                .Add("windowBottom", _
                    VisualStyleElement.Window.FrameBottom.Active)
                .Add("windowLeft", _
                    VisualStyleElement.Window.FrameLeft.Active)
                .Add("windowRight", _
                    VisualStyleElement.Window.FrameRight.Active)
                .Add("windowClose", _
                    VisualStyleElement.Window.CloseButton.Normal)
                .Add("statusBar", _
                    VisualStyleElement.Status.Bar.Normal)
                .Add("statusGripper", _
                    VisualStyleElement.Status.Gripper.Normal)
            End With

            ' Get the sizes and location offsets for the window parts  
            ' as specified by the visual style, and then use this   
            ' information to calcualate the rectangles for each part.
            GetPartDetails()
            CalculateRectangles()
        End Sub

        ' Get the sizes and offsets for the window parts as specified 
        ' by the visual style.
        Private Sub GetPartDetails()
            ' Do nothing further if visual styles are not enabled.
            If Not Application.RenderWithVisualStyles Then
                Return
            End If

            Using g As Graphics = Me.CreateGraphics()
                ' Get the size and offset of the close button.
                If SetRenderer(windowElements("windowClose")) Then
                    closeButtonSize = _
                        renderer.GetPartSize(g, ThemeSizeType.True)
                    closeButtonOffset = _
                        renderer.GetPoint(PointProperty.Offset)
                End If

                ' Get the height of the window caption.
                If SetRenderer(windowElements("windowCaption")) Then
                    captionHeight = renderer.GetPartSize(g, _
                        ThemeSizeType.True).Height
                End If

                ' Get the thickness of the left, bottom, and right 
                ' window frame.
                If SetRenderer(windowElements("windowLeft")) Then
                    frameThickness = renderer.GetPartSize(g, _
                        ThemeSizeType.True).Width
                End If

                ' Get the size of the resizing gripper.
                If SetRenderer(windowElements("statusGripper")) Then
                    gripperSize = renderer.GetPartSize(g, _
                        ThemeSizeType.True)
                End If
            End Using
        End Sub

        ' Use the part metrics to determine the current size of the 
        ' rectangles for all of the window parts.
        Private Sub CalculateRectangles()

            Dim heightMinusFrame As Integer = _
                ClientRectangle.Height - frameThickness

            ' Calculate the window frame rectangles and add them
            ' to the Dictionary of rectangles.
            elementRectangles("windowCaption") = _
                New Rectangle(0, 0, ClientRectangle.Width, _
                captionHeight)
            elementRectangles("windowBottom") = _
                New Rectangle(0, heightMinusFrame, _
                ClientRectangle.Width, frameThickness)
            elementRectangles("windowLeft") = _
                New Rectangle(0, captionHeight, frameThickness, _
                heightMinusFrame - captionHeight)
            elementRectangles("windowRight") = _
                New Rectangle(ClientRectangle.Width - frameThickness, _
                captionHeight, frameThickness, _
                heightMinusFrame - captionHeight)

            ' Calculate the window button rectangle and add it
            ' to the Dictionary of rectangles.
            elementRectangles("windowClose") = _
                New Rectangle(ClientRectangle.Right + _
                closeButtonOffset.X - closeButtonSize.Width - frameThickness, closeButtonOffset.Y, _
                closeButtonSize.Width, closeButtonSize.Height)

            ' Calculate the status bar rectangles and add them
            ' to the Dictionary of rectangles.
            elementRectangles("statusBar") = _
                New Rectangle(frameThickness, _
                heightMinusFrame - statusHeight, _
                ClientRectangle.Width - 2 * frameThickness, _
                statusHeight)
            elementRectangles("statusGripper") = _
                New Rectangle(ClientRectangle.Right - _
                gripperSize.Width - frameThickness, _
                heightMinusFrame - gripperSize.Height, _
                gripperSize.Width, gripperSize.Height)
        End Sub

        Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
            MyBase.OnPaint(e)

            ' Ensure that visual styles are supported.
            If Not Application.RenderWithVisualStyles Then
                Me.Text = "Visual styles are not enabled."
                TextRenderer.DrawText(e.Graphics, Me.Text, Me.Font, _
                    Me.Location, Me.ForeColor)
                Return
            End If

            ' Set the clip region to define the curved corners of 
            ' the caption.
            SetClipRegion()

            ' Draw each part of the window.
            Dim entry As KeyValuePair(Of String, VisualStyleElement)
            For Each entry In windowElements
                If SetRenderer(entry.Value) Then
                    renderer.DrawBackground(e.Graphics, _
                        elementRectangles(entry.Key))
                End If
            Next entry

            ' Draw the caption text.
            TextRenderer.DrawText(e.Graphics, Me.Text, Me.Font, _
                elementRectangles("windowCaption"), Color.White, _
                TextFormatFlags.VerticalCenter Or _
                TextFormatFlags.HorizontalCenter)
        End Sub

        ' Initiate dragging, resizing, or closing the imitation window.
        Private Sub ImitationWindow_MouseDown(ByVal sender As Object, _
            ByVal e As MouseEventArgs) Handles Me.MouseDown

            ' The user clicked the close button.
            If elementRectangles("windowClose"). _
                Contains(e.Location) Then

                windowElements("windowClose") = _
                    VisualStyleElement.Window.CloseButton.Pressed
                isClosing = True

            ' The user clicked the status grip.
            ElseIf elementRectangles("statusGripper"). _
                Contains(e.Location) Then

                isResizing = True
                Me.Cursor = Cursors.SizeNWSE
                resizeOffset.X = Me.Right - Me.Left - e.X
                resizeOffset.Y = Me.Bottom - Me.Top - e.Y

            ' The user clicked the window caption.
            ElseIf elementRectangles("windowCaption"). _
                Contains(e.Location) Then

                isMoving = True
                originalClick.X = e.X
                originalClick.Y = e.Y
            End If
            Invalidate()
        End Sub

        ' Stop any current resizing or moving actions.
        Private Sub ImitationWindow_MouseUp(ByVal sender As Object, _
            ByVal e As MouseEventArgs) Handles Me.MouseUp

            ' Stop moving the location of the window rectangles.
            If isMoving Then
                isMoving = False

            ' Change the cursor back to the default if the 
            ' user stops resizing.
            ElseIf isResizing Then
                isResizing = False

            ' Close the application if the user clicks the 
            ' close button.
            ElseIf elementRectangles("windowClose"). _
                Contains(e.Location) And isClosing Then
                Application.Exit()
            End If
        End Sub

        ' Handle resizing or moving actions.
        Private Sub ImitationWindow_MouseMove(ByVal sender As Object, _
            ByVal e As MouseEventArgs) Handles Me.MouseMove

            ' The left mouse button is down.
            If (MouseButtons.Left And e.Button) = _
                MouseButtons.Left Then

                ' Calculate the new control size if the user is  
                ' dragging the resizing grip.
                If isResizing Then
                    Me.Width = e.X + resizeOffset.X
                    Me.Height = e.Y + resizeOffset.Y
                    CalculateRectangles()

                ' Calculate the new location of the control if   
                ' the user is dragging the window caption.
                ElseIf isMoving Then
                    Dim XChange As Integer = Me.Location.X + _
                        (e.X - originalClick.X)
                    Dim YChange As Integer = Me.Location.Y + _
                        (e.Y - originalClick.Y)
                    Me.Location = New Point(XChange, YChange)

                ' Cancel the closing action if the user clicked and  
                ' held down on the close button, and has dragged the   
                ' pointer outside the button.
                ElseIf Not elementRectangles("windowClose"). _
                    Contains(e.Location) And isClosing Then

                    isClosing = False
                    windowElements("windowClose") = _
                        VisualStyleElement.Window.CloseButton.Normal
                End If

            ' The left mouse button is not down.
            Else
                ' Paint the close button hot if the cursor is on it.
                If elementRectangles("windowClose"). _
                    Contains(e.Location) Then
                    windowElements("windowClose") = _
                        VisualStyleElement.Window.CloseButton.Hot
                Else
                    windowElements("windowClose") = _
                        VisualStyleElement.Window.CloseButton.Normal
                End If

                ' Use a resizing cursor if the cursor is on the 
                ' status grip.
                If elementRectangles("statusGripper"). _
                    Contains(e.Location) Then
                    Me.Cursor = Cursors.SizeNWSE
                Else
                    Me.Cursor = Cursors.Default
                End If
            End If
            Invalidate()
        End Sub

        ' Calculate and set the clipping region for the control  
        ' so that the corners of the title bar are rounded.
        Private Sub SetClipRegion()
            If Not Application.RenderWithVisualStyles Then
                Return
            End If

            Using g As Graphics = Me.CreateGraphics()
                ' Get the current region for the window caption.
                If SetRenderer(windowElements("windowCaption")) Then
                    Dim clipRegion As Region = _
                        renderer.GetBackgroundRegion(g, _
                        elementRectangles("windowCaption"))

                    ' Get the client rectangle, but exclude the   
                    ' region of the window caption.
                    Dim height As Integer = _
                        CInt(clipRegion.GetBounds(g).Height)
                    Dim nonCaptionRect As _
                        New Rectangle(ClientRectangle.X, _
                        ClientRectangle.Y + height, _
                        ClientRectangle.Width, _
                        ClientRectangle.Height - height)

                    ' Add the rectangle to the caption region, and  
                    ' make this region the form's clipping region.
                    clipRegion.Union(nonCaptionRect)
                    Me.Region = clipRegion
                End If
            End Using
        End Sub

        ' Set the VisualStyleRenderer to a new element.
        Private Function SetRenderer(ByVal element As _
            VisualStyleElement) As Boolean

            If Not VisualStyleRenderer.IsElementDefined(element) Then
                Return False
            End If

            If renderer Is Nothing Then
                renderer = New VisualStyleRenderer(element)
            Else
                renderer.SetParameters(element)
            End If

            Return True
        End Function

    End Class
End Namespace

Poznámky

Obor názvů System.Windows.Forms.VisualStyles zveřejňuje VisualStyleElement objekty, které představují všechny prvky ovládacích prvků a uživatelského rozhraní, které jsou podporovány vizuálními styly. Chcete-li nakreslit nebo získat informace o určitém prvku, musíte nastavit VisualStyleRenderer na prvek, který vás zajímá. VisualStyleRenderer se automaticky nastaví na zadaný VisualStyleElement v konstruktoru VisualStyleRenderer, ale můžete také nastavit existující VisualStyleRenderer na jiný prvek voláním metody SetParameters.

Pokud chcete nakreslit prvek, použijte metodu DrawBackground. Třída VisualStyleRenderer také obsahuje metody, jako jsou GetColor a GetEnumValue, které poskytují informace o tom, jak je prvek definován aktuálním vizuálním stylem.

Konstruktor VisualStyleRenderer a mnoho metod VisualStyleRenderer vyvolává výjimky, pokud nejsou v operačním systému povoleny styly vizuálů a vizuální styly jsou použity v klientské oblasti oken aplikací. Ke kontrole těchto podmínek použijte vlastnost staticIsSupported.

Třída VisualStyleRenderer zabalí funkce rozhraní API vizuálních stylů (UxTheme) z části prostředí Windows Shell sady Windows Platform SDK.

Konstruktory

Vlastnosti

Metody

Platí pro

Viz také

• VisualStyleElement
• VisualStyleInformation