HOW TO：建立 UI 型別編輯器
下列程式碼範例包含 HOW TO：建立顯示進度的 Windows Form 控制項 中所述的 FlashTrackBar 控制項的兩個屬性所適用的兩個不同使用者介面 (UI) 型別編輯器。
在第一個範例中，FlashTrackBarValueEditor 將套用到 Value 屬性，並可示範以下各個要點：
FlashTrackBarValueEditor 如何擴充 UITypeEditor 類別。
如何覆寫 EditValue 方法來設定編輯器的屬性。
如何覆寫 GetEditStyle 方法來指定編輯器樣式。
在第二個範例中，FlashTrackBarDarkenByEditor 會擴充 FlashTrackBarValueEditor，並覆寫 Helper 方法來設定屬性。 FlashTrackBarDarkenByEditor 會套用到 FlashTrackBar 的 DarkenBy 屬性。
.gif "注意事項") 注意事項 |
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您必須將這些範例連同 FlashTrackBar 控制項一起編譯，如 HOW TO：建立顯示進度的 Windows Form 控制項 中所述。 |
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;
}
}
}