DataKeyArray.CopyTo(DataKey[], Int32) Methode

  • Referenz

Definition

Namespace:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Kopiert alle Elemente aus dieser Auflistung, beginnend am angegebenen Index im Array, in das angegebene Array des DataKey-Objekts.

public:
 void CopyTo(cli::array <System::Web::UI::WebControls::DataKey ^> ^ array, int index);
public void CopyTo (System.Web.UI.WebControls.DataKey[] array, int index);
member this.CopyTo : System.Web.UI.WebControls.DataKey[] * int -> unit
Public Sub CopyTo (array As DataKey(), index As Integer)

Parameter

array
DataKey[]

Ein nullbasiertes Array von DataKey-Objekten, das die kopierten Elemente aus der Auflistung aufnimmt.

index
Int32

Der erste Index im angegebenen Array, in den der Inhalt kopiert wird.

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie die Methode zum Kopieren der CopyTo DataKey Objekte aus einer DataKeyArray Auflistung in ein Array von DataKey Objekten verwendet wird.


<%@ Page language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  void CustomerGridView_DataBound(Object sender, EventArgs e)
  {           
    // Use the indexer to retrieve the DataKey object for the 
    // first record.
    DataKey key = CustomerGridView.DataKeys[0];

    // Display the value of the primary key for the first
    // record displayed in the GridView control.
    MessageLabel.Text = "The primary key of the first record displayed is " +
      key.Value.ToString() + ".";
  }

  void CopyArray_Click(Object sender, EventArgs e)
  {
      DataKeyArray theKeys = CustomerGridView.DataKeys;
      DataKey[] myNewArray = new DataKey[theKeys.Count];
      theKeys.CopyTo(myNewArray, 0);
      Label2.Visible = true;

      // Display first page key values from the new array.
      for (int i = 0; i < myNewArray.Length; i++)
      {
          Label2.Text += "<br />" + myNewArray[i].Value;
      }

  }

</script>

<html  >

  <head id="Head1" runat="server">
    <title>DataKeyArray Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <h3>DataKeyArray Example</h3>

        <asp:gridview id="CustomerGridView"
          datasourceid="CustomerDataSource"
          autogeneratecolumns="true"
          datakeynames="CustomerID"  
          allowpaging="true"
          ondatabound="CustomerGridView_DataBound" 
          runat="server">

        </asp:gridview>

        <br/>

        <asp:label id="MessageLabel"
          forecolor="Red"
          runat="server"/>

        <!-- This example uses Microsoft SQL Server and connects  -->
        <!-- to the Northwind sample database. Use an ASP.NET     -->
        <!-- expression to retrieve the connection string value   -->
        <!-- from the Web.config file.                            -->
        <asp:sqldatasource id="CustomerDataSource"
          selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
          connectionstring="<%$ ConnectionStrings:NorthwindConnectionString %>" 
          runat="server"/>

        <asp:Button ID="CopyArray" 
            runat="server" 
            Text="Copy DataKeyArray to Array" 
            OnClick="CopyArray_Click" />

        <br />

        <asp:label id="Label2"
          runat="server"
          Visible="false"  
          Text="First page of Copied Array Key Values" />


      </form>
  </body>
</html>


<%@ Page language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  Sub CustomerGridView_DataBound(ByVal sender As Object, ByVal e As EventArgs) Handles CustomerGridView.DataBound
          
    ' Use the indexer to retrieve the DataKey object for the 
    ' first record.
    Dim key As DataKey = CustomerGridView.DataKeys(0)

    ' Display the value of the primary key for the first
    ' record displayed in the GridView control.
    MessageLabel.Text = "The primary key of the first record displayed is " & _
      key.Value.ToString() & "."
  
    End Sub
    
    Sub CopyArray_Click(ByVal sender As Object, ByVal e As EventArgs)
        Dim theKeys As DataKeyArray = CustomerGridView.DataKeys
        Dim myNewArray(theKeys.Count - 1) As DataKey
        theKeys.CopyTo(myNewArray, 0)
        Label2.Visible = True

        ' Display first page key values from the new array.  
        For i As Integer = 0 To myNewArray.Length - 1
            Label2.Text &= "<br />" & myNewArray(i).Value
        Next i

    End Sub
  
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >

  <head id="Head1" runat="server">
    <title>DataKeyArray Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DataKeyArray Example</h3>
                       
        <asp:gridview id="CustomerGridView"
          datasourceid="CustomerDataSource"
          autogeneratecolumns="true"
          datakeynames="CustomerID"  
          allowpaging="true"
          runat="server">
            
        </asp:gridview>
        
        <br/>
        
        <asp:label id="MessageLabel"
          forecolor="Red"
          runat="server"/>
            
        <!-- This example uses Microsoft SQL Server and connects  -->
        <!-- to the Northwind sample database. Use an ASP.NET     -->
        <!-- expression to retrieve the connection string value   -->
        <!-- from the Web.config file.                            -->
        <asp:sqldatasource id="CustomerDataSource"
          selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
          connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
          runat="server"/>

        <asp:Button ID="CopyArray" 
            runat="server" 
            Text="Copy DataKeyArray to Array" 
            OnClick="CopyArray_Click" />

        <br />

        <asp:label id="Label2"
          runat="server"
          Visible="false"  
          Text="First page of Copied Array Key Values" />
            
      </form>
  </body>
</html>

Hinweise

Verwenden Sie die CopyTo Methode, um die Elemente aus der Auflistung in das angegebene Array zu kopieren, beginnend mit dem angegebenen Index. Das Array kann dann verwendet werden, um auf die Elemente in der Auflistung zuzugreifen.

Hinweis

Sie müssen ein nullbasiertes Array für den array Parameter verwenden.

Gilt für

Siehe auch