DataGridDesigner クラスとは何？わかりやすく解説 Weblio辞書

.NET Framework クラスライブラリリファレンス

索引トップ用語の索引ランキング

DataGridDesigner クラス

DataGrid Web サーバーコントロールのデザイン時の動作を拡張します。

名前空間: System.Web.UI.Design.WebControls
アセンブリ: System.Design (system.design.dll 内)
構文

Visual Basic (宣言)

Public Class DataGridDesigner
    Inherits BaseDataListDesigner

Visual Basic (使用法)

Dim instance As DataGridDesigner

public class DataGridDesigner : BaseDataListDesigner

C++

public ref class DataGridDesigner : public
 BaseDataListDesigner

public class DataGridDesigner extends BaseDataListDesigner

JScript

public class DataGridDesigner extends
 BaseDataListDesigner

使用例

DataGridDesigner クラスを拡張する方法を次のコード例に示します。このコードは、GetDesignTimeHtml メソッドをオーバーライドして、DataGrid コントロールがデザインサーフェイスに表示されるときに CellPadding、BorderWidth、および BorderColor の各プロパティをカスタマイズします。

Visual Basic

Imports System
Imports System.Diagnostics
Imports System.ComponentModel
Imports System.Drawing
Imports System.Web.UI.Design.WebControls
Imports System.Web.UI.WebControls

Namespace Examples.AspNet

    ' Create a designer class for the SimpleDataList class.
    <System.Security.Permissions.SecurityPermission( _
    System.Security.Permissions.SecurityAction.Demand, _
    Flags:=System.Security.Permissions.SecurityPermissionFlag.UnmanagedCode)>
 _
    Public Class SimpleDataListDesigner
        Inherits DataListDesigner

        Private simpleList As SimpleDataList


        ' Override the GetDesignTimeHtml method to add style to the
 control
        ' on the design surface.
        Public Overrides Function
 GetDesignTimeHtml() As String
            ' Cast the control to the Component property of the designer.
            simpleList = CType(Component, SimpleDataList)

            Dim designTimeHtml As String
 = Nothing

            ' Create variables to hold current property values.
            Dim oldBorderWidth As Unit = simpleList.BorderWidth
            Dim oldBorderColor As Color = simpleList.BorderColor

            ' Set the properties and generate the design-time HTML.
            If (simpleList.Enabled) Then
                Try
                    simpleList.BorderWidth = Unit.Point(5)
                    simpleList.BorderColor = Color.Purple
                    designTimeHtml = MyBase.GetDesignTimeHtml()

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

                    ' Return the properties to their original settings.
                Finally
                    simpleList.BorderWidth = oldBorderWidth
                    simpleList.BorderColor = oldBorderColor
                End Try
                ' If the list is not enabled, call the GetEmptyDesignTimeHtml
                ' method.
            Else
                designTimeHtml = GetEmptyDesignTimeHtml()
            End If

            Return designTimeHtml

        End Function

        Protected Overrides Function
 GetEmptyDesignTimeHtml() As String
            Dim emptyText As String

            ' Check the CanEnterTemplateMode property to
            ' specify which text to display if ItemTemplate 
            ' does not contain a value.
            If CanEnterTemplateMode Then
                emptyText = _
                    "<b>Either the Enabled property value
 is false " + _
                    "or you need to set the ItemTemplate for this
 " + _
                    "control.<br>Right-click to edit templates.</b>"
            Else
                emptyText = _
                    "<b>You cannot edit templates in this
 view.<br>" + _
                    "Switch to HTML view to define the ItemTemplate.</b>"
            End If

            Return CreatePlaceHolderDesignTimeHtml(emptyText)
        End Function

        ' Generate HTML to indicate that an error has occurred.
        Protected Overrides Function
 GetErrorDesignTimeHtml(ByVal exc As _
            Exception) As String

            Return CreatePlaceHolderDesignTimeHtml( _
                "<b>An error occurred</b>.<br>Check
 to ensure that all " + _
                "properties are valid.")
        End Function


        ' Override the Initialize method to ensure that
        ' only an instance of the SimpleDataList class is
        ' used by this designer class.
        Public Overrides Sub
 Initialize(ByVal component As IComponent)
            simpleList = CType(component, SimpleDataList)

            If IsNothing(simpleList) Then
                Throw New ArgumentException("Must
 be a SimpleDataList.", "component")
            End If

            MyBase.Initialize(component)
        End Sub
    End Class
End Namespace

DesignerAttribute 属性を使用してデザイナを DataGrid コントロールに関連付ける方法を次の例に示します。

Visual Basic

' Override the Initialize method to ensure that
' only an instance of the SimpleDataList class is
' used by this designer class.
Public Overrides Sub Initialize(ByVal
 component As IComponent)
    simpleList = CType(component, SimpleDataList)

    If IsNothing(simpleList) Then
        Throw New ArgumentException("Must
 be a SimpleDataList.", "component")
    End If

    MyBase.Initialize(component)
End Sub

.NET Framework のセキュリティ

AspNetHostingPermission (ホスト環境での動作に必要なアクセス許可)要求値 : LinkDemand。アクセス許可値 : Minimal。
AspNetHostingPermission (ホスト環境での動作に必要なアクセス許可)要求値 : InheritanceDemand。アクセス許可値 : Minimal。

継承階層

System.Object
   System.ComponentModel.Design.ComponentDesigner
     System.Web.UI.Design.HtmlControlDesigner
       System.Web.UI.Design.ControlDesigner
         System.Web.UI.Design.TemplatedControlDesigner
           System.Web.UI.Design.WebControls.BaseDataListDesigner
            System.Web.UI.Design.WebControls.DataGridDesigner

スレッドセーフ

この型の public static (Visual Basic では Shared) メンバはすべて、スレッドセーフです。インスタンスメンバの場合は、スレッドセーフであるとは限りません。

プラットフォーム

Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition