Gewusst wie: Erstellen eines UI-Typ-Editors

Die folgenden Codebeispiele enthalten zwei unterschiedliche UI-Typ-Editoren für zwei Eigenschaften des FlashTrackBar-Steuerelements, das unter Gewusst wie: Erstellen eines Windows Forms-Steuerelements, das den Fortschritt anzeigt beschrieben wird.

Im ersten Beispiel wird der FlashTrackBarValueEditor auf die Value-Eigenschaft angewendet, und die folgenden Aspekte werden veranschaulicht:

• Wie der FlashTrackBarValueEditor die UITypeEditor-Klasse erweitert.

• Wie die EditValue-Methode überschrieben wird, um die Eigenschaften des Editors festzulegen.

• Wie die GetEditStyle-Methode überschrieben wird, um den Stil für den Editor anzugeben.

Im zweiten Beispiel erweitert der FlashTrackBarDarkenByEditor den FlashTrackBarValueEditor und überschreibt eine Hilfsmethode, um Eigenschaften festzulegen. Der FlashTrackBarDarkenByEditor wird auf die DarkenBy-Eigenschaft der FlashTrackBar angewendet.

FlashTrackBarValueEditor

Imports System
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Drawing.Design
Imports System.Windows.Forms
Imports System.Diagnostics
Imports System.Windows.Forms.ComponentModel
Imports System.Windows.Forms.Design

Namespace Microsoft.Samples.WinForms.VB.FlashTrackBar

    <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
    Public Class FlashTrackBarValueEditor
        Inherits UITypeEditor

        Private edSvc As IWindowsFormsEditorService


        Overridable Protected Sub SetEditorProps(editingInstance As FlashTrackBar, editor As FlashTrackBar)
            editor.ShowValue = true
            editor.StartColor = Color.Navy
            editor.EndColor = Color.White
            editor.ForeColor = Color.White
            editor.Min = editingInstance.Min
            editor.Max = editingInstance.Max
        End Sub

        Overrides OverLoads Public Function EditValue(context As ITypeDescriptorContext, provider As IServiceProvider, value As object) As Object

            If ((context IsNot Nothing) And (context.Instance IsNot Nothing) And (provider IsNot Nothing)) Then

                edSvc = CType(provider.GetService(GetType(IWindowsFormsEditorService)), IWindowsFormsEditorService)

                If (edSvc IsNot Nothing) Then

                    Dim trackBar As FlashTrackBar = New FlashTrackBar()
                    AddHandler trackBar.ValueChanged, AddressOf Me.ValueChanged
                    SetEditorProps(CType(context.Instance, FlashTrackBar), TrackBar)

                    Dim asInt As Boolean = True

                    If (TypeOf value Is Integer) Then
                        trackBar.Value = CInt(value)
                    ElseIf (TypeOf value Is System.Byte) Then
                        asInt = False
                        trackBar.Value = CType(value, Byte)
                    End If

                    edSvc.DropDownControl(trackBar)

                    If (asInt) Then
                        value = trackBar.Value
                    Else
                        value = CType(trackBar.Value, Byte)
                    End If

                End If

            End If

            Return value

         End Function

        Overrides OverLoads Public Function GetEditStyle(context As ITypeDescriptorContext) As UITypeEditorEditStyle
            If ((context IsNot Nothing) And (context.Instance IsNot Nothing)) Then
                Return UITypeEditorEditStyle.DropDown
            End If
            Return MyBase.GetEditStyle(context)
        End Function

        private Sub ValueChanged(sender As object, e As EventArgs)
            If (edSvc IsNot Nothing) Then
                edSvc.CloseDropDown()
            End If
        End Sub

    End Class

End Namespace

namespace Microsoft.Samples.WinForms.Cs.FlashTrackBar {
    using System;
    using System.ComponentModel;
    using System.ComponentModel.Design;
    using System.Diagnostics;
    using System.Drawing;
    using System.Drawing.Drawing2D;
    using System.Drawing.Design;
    using System.Windows.Forms;
    using System.Windows.Forms.ComponentModel;
    using System.Windows.Forms.Design;

    [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")] 
    public class FlashTrackBarValueEditor : System.Drawing.Design.UITypeEditor {

        private IWindowsFormsEditorService edSvc = null;

        protected virtual void SetEditorProps(FlashTrackBar editingInstance, FlashTrackBar editor) {
            editor.ShowValue = true;
            editor.StartColor = Color.Navy;
            editor.EndColor = Color.White;
            editor.ForeColor = Color.White;
            editor.Min = editingInstance.Min;
            editor.Max = editingInstance.Max;
        }

        public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value) {

            if (context != null
                && context.Instance != null
                && provider != null) {

                edSvc = (IWindowsFormsEditorService)provider.GetService(typeof(IWindowsFormsEditorService));

                if (edSvc != null) {
                    FlashTrackBar trackBar = new FlashTrackBar();
                    trackBar.ValueChanged += new EventHandler(this.ValueChanged);
                    SetEditorProps((FlashTrackBar)context.Instance, trackBar);
                    bool asInt = true;
                    if (value is int) {
                        trackBar.Value = (int)value;
                    }
                    else if (value is byte) {
                        asInt = false;
                        trackBar.Value = (byte)value;
                    }
                    edSvc.DropDownControl(trackBar);
                    if (asInt) {
                        value = trackBar.Value;
                    }
                    else {
                        value = (byte)trackBar.Value;
                    }
                }
            }

            return value;
        }

        public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context) {
            if (context != null && context.Instance != null) {
                return UITypeEditorEditStyle.DropDown;
            }
            return base.GetEditStyle(context);
        }

        private void ValueChanged(object sender, EventArgs e) {
            if (edSvc != null) {
                edSvc.CloseDropDown();
            }
        }
    }
}

FlashTrackBarDarkenByEditor

Imports System
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Drawing.Design
Imports System.Windows.Forms
Imports System.Diagnostics

Namespace Microsoft.Samples.WinForms.VB.FlashTrackBar 

   Public Class FlashTrackBarDarkenByEditor 
        Inherits FlashTrackBarValueEditor 

       Overrides Protected Sub SetEditorProps(editingInstance As FlashTrackBar, editor As FlashTrackBar) 
           MyBase.SetEditorProps(editingInstance, editor)
           editor.Min = 0
           editor.Max = System.Byte.MaxValue
       End Sub

   End Class

End Namespace

namespace Microsoft.Samples.WinForms.Cs.FlashTrackBar {
   using System;
   using System.ComponentModel;
   using System.ComponentModel.Design;
   using System.Diagnostics;
   using System.Drawing;
   using System.Drawing.Drawing2D;
   using System.Drawing.Design;
   using System.Windows.Forms;
   using System.Windows.Forms.ComponentModel;
   using System.Windows.Forms.Design;

   public class FlashTrackBarDarkenByEditor : FlashTrackBarValueEditor {
       protected override void SetEditorProps(FlashTrackBar editingInstance, FlashTrackBar editor) {
           base.SetEditorProps(editingInstance, editor);
           editor.Min = 0;
           editor.Max = byte.MaxValue;
       }
   }
}

Siehe auch

Aufgaben

Gewusst wie: Implementieren eines Typ-Editors für die Benutzeroberfläche

Weitere Ressourcen

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