ButtonDesigner.GetDesignTimeHtml Method
Gets the HTML that is used to represent the control at design time.
[Visual Basic] Overrides Public Function GetDesignTimeHtml() As String [C#] public override string GetDesignTimeHtml(); [C++] public: String* GetDesignTimeHtml(); [JScript] public override function GetDesignTimeHtml() : String;
Return Value
The HTML that is used to represent the control at design time.
Remarks
Unless overridden, the GetDesignTimeHtml method of the ButtonDesigner class sets the Text property of the control to the ID property of the control, if the Text property is empty.
Example
[Visual Basic] The following code example creates a custom designer class, named CustomButtonDesigner, that derives from the ButtonDesigner class. It overrides the GetDesignTimeHtml method. If the Button.Text property has not been set previously, a call to this method sets it to a string and displays that string on the design surface. If the Text property has been set already, the existing property value is displayed.
[Visual Basic]
' Create a class that derives from ButtonDesigner
' that displays the custom SampleButton control
' on a design surface.
Imports System
Imports System.Design
Imports System.Drawing
Imports System.ComponentModel
Imports System.Diagnostics
Imports System.Web.UI.WebControls
Imports System.Web.UI.Design.WebControls
Imports Examples.AspNet
Namespace Examples.AspNet.Design
' <System.Security.Permissions.SecurityPermission( _
' System.Security.Permissions.SecurityAction.Demand, _
' Flags:=System.Security.Permissions.SecurityPermissionFlag.UnmanagedCode)> _
Public Class SampleButtonDesigner
Inherits ButtonDesigner
' Override the GetDesignTimeHtml method.
Public Overrides Function GetDesignTimeHtml() As String
Dim sampleButton As SampleButton = CType(Component, SampleButton)
Dim designTimeHtml As String = Nothing
' Check the control's BorderStyle property
' to conditionally render design-time HTML.
If (sampleButton.BorderStyle = BorderStyle.NotSet) Then
' Create variables to hold current property settings.
Dim oldBorderStyle As BorderStyle = sampleButton.BorderStyle
Dim oldBorderWidth As Unit = sampleButton.BorderWidth
Dim oldBorderColor As Color = sampleButton.BorderColor
' Set properties and the design-time HTML.
Try
sampleButton.BorderStyle = BorderStyle.Dashed
sampleButton.BorderWidth = Unit.Pixel(3)
sampleButton.BorderColor = Color.Blue
designTimeHtml = MyBase.GetDesignTimeHtml()
' If an exception occurs, call the GetErrorDesignTimeHtml
' method.
Catch ex As Exception
designTimeHtml = GetErrorDesignTimeHtml(ex)
' Return properties to their original settings.
Finally
sampleButton.BorderStyle = oldBorderStyle
sampleButton.BorderWidth = oldBorderWidth
sampleButton.BorderColor = oldBorderColor
End Try
Else
designTimeHtml = MyBase.GetDesignTimeHtml()
End If
Return designTimeHTML
End Function
End Class
End Namespace
[C#, C++, JScript] No example is available for C#, C++, or JScript. To view a Visual Basic example, click the Language Filter button
in the upper-left corner of the page.
Requirements
Platforms: Windows 2000, Windows XP Professional, Windows Server 2003 family
.NET Framework Security:
- Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries From Partially Trusted Code
See Also
ButtonDesigner Class | ButtonDesigner Members | System.Web.UI.Design.WebControls Namespace