TextBoxRenderer Classe

Definição

public ref class TextBoxRenderer sealed

public ref class TextBoxRenderer abstract sealed

public sealed class TextBoxRenderer

public static class TextBoxRenderer

type TextBoxRenderer = class

Public NotInheritable Class TextBoxRenderer

Public Class TextBoxRenderer

Herança

Object

TextBoxRenderer

Exemplos

O exemplo de código a seguir demonstra como criar um controle personalizado que usa o DrawTextBox método para desenhar uma caixa de texto. O controle também permite que o usuário selecione um dos TextFormatFlags valores a serem aplicados ao texto da caixa de texto.

#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::Windows::Forms;
using namespace System::Windows::Forms::VisualStyles;

namespace TextBoxRendererSample
{
    public ref class CustomTextBox : public Control
    {
    private:
        TextFormatFlags textFlags;
        ComboBox^ textFormatFlagsComboBox;
        Rectangle textBorder;
        Rectangle textRectangle;
        StringBuilder^ textMeasurements;

    public:
        CustomTextBox():Control()
        {
            textFlags = TextFormatFlags::Default;
            textFormatFlagsComboBox = gcnew ComboBox();

            textMeasurements = gcnew StringBuilder();

            this->Location = Point(10, 10);
            this->Size = System::Drawing::Size(300, 200);
            this->Font = SystemFonts::IconTitleFont;
            this->Text = "This is a long sentence that will exceed " +
                "the text box bounds";

            textBorder.Location = Point(10, 10);
            textBorder.Size = System::Drawing::Size(200, 50);
            textRectangle.Location = Point(textBorder.X + 2,
                textBorder.Y + 2);
            textRectangle.Size =  System::Drawing::Size(textBorder.Size.Width - 4,
                textBorder.Height - 4);

            textFormatFlagsComboBox->Location = Point(10, 100);
            textFormatFlagsComboBox->Size = System::Drawing::Size(150, 20);
            textFormatFlagsComboBox->SelectedIndexChanged +=
                gcnew EventHandler(this, 
                &CustomTextBox::textFormatFlagsComboBox_SelectedIndexChanged);

            // Populate the combo box with the TextFormatFlags value names.
            for each (String^ name in Enum::GetNames(TextFormatFlags::typeid))
            {
                textFormatFlagsComboBox->Items->Add(name);
            }

            textFormatFlagsComboBox->SelectedIndex = 0;
            this->Controls->Add(textFormatFlagsComboBox);
        }

        // Use DrawText with the current TextFormatFlags.

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

            if (TextBoxRenderer::IsSupported)
            {
                TextBoxRenderer::DrawTextBox(e->Graphics, textBorder, this->Text,
                    this->Font, textRectangle, textFlags, TextBoxState::Normal);

                this->Parent->Text = "CustomTextBox Enabled";
            }
            else
            {
                this->Parent->Text = "CustomTextBox Disabled";
            }
        }

        // Assign the combo box selection to the display text.
    private:
        void textFormatFlagsComboBox_SelectedIndexChanged(
            Object^ sender, EventArgs^ e)
        {
            this->textFlags = (TextFormatFlags)Enum::Parse(
                TextFormatFlags::typeid,
                (String^)textFormatFlagsComboBox->Items[
                    textFormatFlagsComboBox->SelectedIndex]);

                    Invalidate();
        }
    };

    public ref class Form1 : public Form
    {
    public:
        Form1()
        {
            __super::Form();
            this->Size = System::Drawing::Size(350, 200);
            CustomTextBox^ textBox1 = gcnew CustomTextBox();
            Controls->Add(textBox1);
        }
    };
}

using namespace TextBoxRendererSample;

[STAThread]
int main()
{     
    // The call to EnableVisualStyles below does not affect whether 
    // TextBoxRenderer draws the text box; as long as visual styles 
    // are enabled by the operating system, TextBoxRenderer will 
    // draw the text box.
    Application::EnableVisualStyles();
    Application::Run(gcnew Form1());
}

using System;
using System.Text;
using System.Drawing;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;

namespace TextBoxRendererSample
{
    class Form1 : Form
    {
        public Form1()
            : base()
        {
            this.Size = new Size(350, 200);
            CustomTextBox TextBox1 = new CustomTextBox();
            Controls.Add(TextBox1);
        }

        [STAThread]
        static void Main()
        {
            // The call to EnableVisualStyles below does not affect whether 
            // TextBoxRenderer draws the text box; as long as visual styles 
            // are enabled by the operating system, TextBoxRenderer will 
            // draw the text box.
            Application.EnableVisualStyles();
            Application.Run(new Form1());
        }
    }

    public class CustomTextBox : Control
    {
        private TextFormatFlags textFlags = TextFormatFlags.Default;
        ComboBox comboBox1 = new ComboBox();
        Rectangle textBorder = new Rectangle();
        Rectangle textRectangle = new Rectangle();
        StringBuilder textMeasurements = new StringBuilder();

        public CustomTextBox()
            : base()
        {
            this.Location = new Point(10, 10);
            this.Size = new Size(300, 200);
            this.Font = SystemFonts.IconTitleFont;
            this.Text = "This is a long sentence that will exceed " +
                "the text box bounds";

            textBorder.Location = new Point(10, 10);
            textBorder.Size = new Size(200, 50);
            textRectangle.Location = new Point(textBorder.X + 2,
                textBorder.Y + 2);
            textRectangle.Size = new Size(textBorder.Size.Width - 4,
                textBorder.Height - 4);

            comboBox1.Location = new Point(10, 100);
            comboBox1.Size = new Size(150, 20);
            comboBox1.SelectedIndexChanged +=
                new EventHandler(comboBox1_SelectedIndexChanged);

            // Populate the combo box with the TextFormatFlags value names.
            foreach (string name in Enum.GetNames(typeof(TextFormatFlags)))
            {
                comboBox1.Items.Add(name);
            }

            comboBox1.SelectedIndex = 0;
            this.Controls.Add(comboBox1);
        }

        // Use DrawText with the current TextFormatFlags.
        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);

            if (TextBoxRenderer.IsSupported)
            {
                TextBoxRenderer.DrawTextBox(e.Graphics, textBorder, this.Text,
                    this.Font, textRectangle, textFlags, TextBoxState.Normal);

                this.Parent.Text = "CustomTextBox Enabled";
            }
            else
            {
                this.Parent.Text = "CustomTextBox Disabled";
            }
        }

        // Assign the combo box selection to the display text.
        void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            this.textFlags = (TextFormatFlags)Enum.Parse(
                typeof(TextFormatFlags),
                (string)comboBox1.Items[comboBox1.SelectedIndex]);
            Invalidate();
        }
    }
}

Imports System.Text
Imports System.Drawing
Imports System.Windows.Forms
Imports System.Windows.Forms.VisualStyles

Namespace TextBoxRendererSample

    Class Form1
        Inherits Form

        Public Sub New()
            Me.Size = New Size(350, 200)
            Dim TextBox1 As New CustomTextBox()
            Controls.Add(TextBox1)
        End Sub

        <STAThread()> _
        Shared Sub Main()
            ' The call to EnableVisualStyles below does not affect whether 
            ' TextBoxRenderer draws the text box; as long as visual styles 
            ' are enabled by the operating system, TextBoxRenderer will 
            ' draw the text box.
            Application.EnableVisualStyles()
            Application.Run(New Form1())
        End Sub
    End Class

    Public Class CustomTextBox
        Inherits Control

        Private textFlags As TextFormatFlags = TextFormatFlags.Default
        Private WithEvents comboBox1 As New ComboBox()
        Private textBorder As New Rectangle()
        Private textRectangle As New Rectangle()
        Private textMeasurements As New StringBuilder()

        Public Sub New()

            With Me
                .Location = New Point(10, 10)
                .Size = New Size(300, 200)
                .Font = SystemFonts.IconTitleFont
                .Text = "This is a long sentence that will exceed " + _
                    "the text box bounds"
            End With

            textBorder.Location = New Point(10, 10)
            textBorder.Size = New Size(200, 50)
            textRectangle.Location = New Point(textBorder.X + 2, _
                textBorder.Y + 2)
            textRectangle.Size = New Size(textBorder.Size.Width - 4, _
                textBorder.Height - 4)

            comboBox1.Location = New Point(10, 100)
            comboBox1.Size = New Size(150, 20)

            ' Populate the combo box with the TextFormatFlags value names.
            Dim name As String
            For Each name In [Enum].GetNames(GetType(TextFormatFlags))
                comboBox1.Items.Add(name)
            Next name

            comboBox1.SelectedIndex = 0
            Me.Controls.Add(comboBox1)
        End Sub

        ' Use DrawText with the current TextFormatFlags.
        Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
            MyBase.OnPaint(e)

            If TextBoxRenderer.IsSupported Then
                TextBoxRenderer.DrawTextBox(e.Graphics, textBorder, Me.Text, _
                    Me.Font, textRectangle, textFlags, TextBoxState.Normal)
                Me.Parent.Text = "CustomTextBox Enabled"
            Else
                Me.Parent.Text = "CustomTextBox Disabled"
            End If
        End Sub

        ' Assign the combo box selection to the display text.
        Private Sub comboBox1_SelectedIndexChanged(ByVal sender As Object, _
            ByVal e As EventArgs) Handles comboBox1.SelectedIndexChanged

            Me.textFlags = CType([Enum].Parse(GetType(TextFormatFlags), _
                CStr(comboBox1.Items(comboBox1.SelectedIndex))), _
                TextFormatFlags)
            Invalidate()
        End Sub

    End Class
End Namespace

Comentários

A TextBoxRenderer classe fornece um conjunto de static métodos que podem ser usados para renderizar um controle de caixa de texto com o estilo visual atual do sistema operacional. Renderizar um controle refere-se a desenhar a interface do usuário de um controle. Isso será útil se você estiver desenhando um controle personalizado que deve ter a aparência do estilo visual atual. Para desenhar uma caixa de texto, use um dos DrawTextBox métodos. Esses métodos fornecem uma variedade de opções, como aplicar formatação de texto ou especificar limites de texto.

Se os estilos visuais estiverem habilitados no sistema operacional e os estilos visuais forem aplicados à área do cliente das janelas do aplicativo, DrawTextBox desenhará a caixa de texto com o estilo visual atual. Caso contrário, DrawTextBox lançará um InvalidOperationException. Para determinar se os membros dessa classe podem ser usados, você pode verificar o valor da IsSupported propriedade.

Essa classe encapsula a funcionalidade de um System.Windows.Forms.VisualStyles.VisualStyleRenderer que é definido como um dos elementos da System.Windows.Forms.VisualStyles.VisualStyleElement.TextBox.TextEdit classe. Para obter mais informações, consulte Controles de renderização com estilos visuais.

Propriedades

Métodos

Aplica-se a

Confira também

• VisualStyleRenderer
• VisualStyleElement