DataListDesigner.GetDesignTimeHtml 方法

public:
 override System::String ^ GetDesignTimeHtml();

public override string GetDesignTimeHtml ();

override this.GetDesignTimeHtml : unit -> string

Public Overrides Function GetDesignTimeHtml () As String

返回

设计时用于表示 DataList 控件的 HTML。

示例

下面的代码示例演示如何重写 GetDesignTimeHtml 方法。 如果控件的 属性为 true，则会更改控件WebControl.Enabled在设计图面上的外观。

代码使用 Try...Catch...Finally 语法执行以下操作：

• 节 Try 更改控件属性的值。

• 节 Catch 捕获任何异常并将其发送到 GetErrorDesignTimeHtml 方法。

• 节 Finally 将属性设置为其原始值。

此代码示例是为 DataListDesigner 类提供的一个更大示例的一部分。

public override string GetDesignTimeHtml()
{
    string designTimeHtml = String.Empty;

    simpleGView = (SimpleGridView)Component;

    // Check the control's BorderStyle property to  
    // conditionally render design-time HTML.
    if (simpleGView.BorderStyle == BorderStyle.NotSet)
    {
        // Save the current property settings in variables.
        int oldCellPadding = simpleGView.CellPadding;
        Unit oldBorderWidth = simpleGView.BorderWidth;
        Color oldBorderColor = simpleGView.BorderColor;

        // Set properties and generate the design-time HTML.
        try
        {
            simpleGView.Caption = "SimpleGridView";
            simpleGView.CellPadding = 1;
            simpleGView.BorderWidth = Unit.Pixel(3);
            simpleGView.BorderColor = Color.Red;

            designTimeHtml = base.GetDesignTimeHtml();
        }
        catch (Exception ex)
        {
            // Get HTML from the GetErrorDesignTimeHtml 
            // method if an exception occurs.
            designTimeHtml = GetErrorDesignTimeHtml(ex);

            // Return the properties to their original values.
        }
        finally
        {
            simpleGView.CellPadding = oldCellPadding;
            simpleGView.BorderWidth = oldBorderWidth;
            simpleGView.BorderColor = oldBorderColor;
        }
    }
    else
    {
        designTimeHtml = base.GetDesignTimeHtml();
    }

    return designTimeHtml;
}

protected override string
    GetErrorDesignTimeHtml(System.Exception exc)
{
    return CreatePlaceHolderDesignTimeHtml(
        "ASPNET.Examples: An error occurred while rendering the GridView.");
}

Public Overrides Function GetDesignTimeHtml() As String
    Dim designTimeHtml As String = String.Empty

    simpleGView = CType(Component, SimpleGridView)

    ' Check the control's BorderStyle property to  
    ' conditionally render design-time HTML.
    If (simpleGView.BorderStyle = BorderStyle.NotSet) Then
        ' Save the current property settings in variables.
        Dim oldCellPadding As Integer = simpleGView.CellPadding
        Dim oldBorderWidth As Unit = simpleGView.BorderWidth
        Dim oldBorderColor As Color = simpleGView.BorderColor

        ' Set properties and generate the design-time HTML.
        Try
            simpleGView.Caption = "SimpleGridView"
            simpleGView.CellPadding = 1
            simpleGView.BorderWidth = Unit.Pixel(3)
            simpleGView.BorderColor = Color.Red

            designTimeHtml = MyBase.GetDesignTimeHtml()

        Catch ex As Exception
            ' Get HTML from the GetErrorDesignTimeHtml 
            ' method if an exception occurs.
            designTimeHtml = GetErrorDesignTimeHtml(ex)

            ' Return the properties to their original values.
        Finally
            simpleGView.CellPadding = oldCellPadding
            simpleGView.BorderWidth = oldBorderWidth
            simpleGView.BorderColor = oldBorderColor
        End Try

    Else
        designTimeHtml = MyBase.GetDesignTimeHtml()
    End If

    Return designTimeHtml
End Function

Protected Overrides Function _
    GetErrorDesignTimeHtml(ByVal exc As Exception) As String

    Return CreatePlaceHolderDesignTimeHtml( _
        "ASPNET.Examples: An error occurred while rendering the GridView.")

End Function

适用于

另请参阅

• ControlDesigner
• ASP.NET 控件设计器概述