GridView.SelectedIndexChanging Kejadian

Referensi

Definisi

Ruang nama:: System.Web.UI.WebControls

Rakitan:: System.Web.dll

Penting

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Terjadi saat tombol Pilih baris diklik, tetapi sebelum GridView kontrol menangani operasi pilih.

public:
 event System::Web::UI::WebControls::GridViewSelectEventHandler ^ SelectedIndexChanging;

public event System.Web.UI.WebControls.GridViewSelectEventHandler SelectedIndexChanging;

member this.SelectedIndexChanging : System.Web.UI.WebControls.GridViewSelectEventHandler

Public Custom Event SelectedIndexChanging As GridViewSelectEventHandler

Jenis Acara

GridViewSelectEventHandler

Contoh

Contoh berikut menunjukkan cara menggunakan SelectedIndexChanging peristiwa untuk membatalkan operasi tertentu.


<%@ 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 CustomersGridView_SelectedIndexChanged(Object sender, EventArgs e)
  {
    // Get the currently selected row using the SelectedRow property.
    GridViewRow row = CustomersGridView.SelectedRow;
        
    // Display the first name from the selected row.
    // In this example, the third column (index 2) contains
    // the first name.
    MessageLabel.Text = "You selected " + row.Cells[2].Text + ".";
  }

  void CustomersGridView_SelectedIndexChanging(Object sender, GridViewSelectEventArgs e)
  {
    // Get the currently selected row. Because the SelectedIndexChanging event
    // occurs before the select operation in the GridView control, the
    // SelectedRow property cannot be used. Instead, use the Rows collection
    // and the NewSelectedIndex property of the e argument passed to this 
    // event handler.
    GridViewRow row = CustomersGridView.Rows[e.NewSelectedIndex];

    // You can cancel the select operation by using the Cancel
    // property. For this example, if the user selects a customer with 
    // the ID "ANATR", the select operation is canceled and an error message
    // is displayed.
    if (row.Cells[1].Text == "ANATR")
    {
      e.Cancel = true;
      MessageLabel.Text = "You cannot select " + row.Cells[2].Text + "."; 
    }
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridView Select Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
     <h3>GridView Select Example</h3>

     <asp:gridview id="CustomersGridView" 
       datasourceid="CustomersSource" 
       autogeneratecolumns="False"
       autogenerateselectbutton="True"
       selectedindex="1"
       onselectedindexchanged="CustomersGridView_SelectedIndexChanged"
       onselectedindexchanging="CustomersGridView_SelectedIndexChanging"   
       runat="server" DataKeyNames="CustomerID">
                
         <Columns>
             <asp:BoundField DataField="CustomerID" 
                 HeaderText="CustomerID" 
                 InsertVisible="False" ReadOnly="True" 
                 SortExpression="CustomerID" />
             <asp:BoundField DataField="FirstName" 
                 HeaderText="FirstName" 
                 SortExpression="FirstName" />
             <asp:BoundField DataField="MiddleName" 
                 HeaderText="MiddleName" 
                 SortExpression="MiddleName" />
             <asp:BoundField DataField="LastName" 
                 HeaderText="LastName" 
                 SortExpression="LastName" />
             <asp:BoundField DataField="Phone" 
                 HeaderText="Phone" 
                 SortExpression="Phone" />
         </Columns>
                
       <selectedrowstyle backcolor="LightCyan"
         forecolor="DarkBlue"
         font-bold="true"/>  
                
     </asp:gridview>
            
      <br/>
            
      <asp:label id="MessageLabel"
        forecolor="Red"
        runat="server"/>
            
      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="CustomersSource"
        selectcommand="SELECT CustomerID, FirstName, MiddleName, LastName, Phone FROM SalesLT.Customer"
        connectionstring="<%$ ConnectionStrings:AdventureWorksLTConnectionString %>" 
        runat="server"/>
            
    </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 CustomersGridView_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
        
    ' Get the currently selected row using the SelectedRow property.
    Dim row As GridViewRow = CustomersGridView.SelectedRow
        
    ' Display the first name from the selected row.
    ' In this example, the third column (index 2) contains
    ' the first name.
    MessageLabel.Text = "You selected " & row.Cells(2).Text & "."
  End Sub

  Sub CustomersGridView_SelectedIndexChanging(ByVal sender As Object, ByVal e As GridViewSelectEventArgs)
        
    ' Get the currently selected row. Because the SelectedIndexChanging event
    ' occurs before the select operation in the GridView control, the
    ' SelectedRow property cannot be used. Instead, use the Rows collection
    ' and the NewSelectedIndex property of the e argument passed to this 
    ' event handler.
    Dim row As GridViewRow = CustomersGridView.Rows(e.NewSelectedIndex)

    ' You can cancel the select operation by using the Cancel
    ' property. For this example, if the user selects a customer with 
    ' the ID "ANATR", the select operation is canceled and an error message
    ' is displayed.
    If row.Cells(1).Text = "ANATR" Then
        e.Cancel = True
        MessageLabel.Text = "You cannot select " + row.Cells(2).Text & "."
    End If
    
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridView Select Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
     <h3>GridView Select Example</h3>

     <asp:gridview id="CustomersGridView" 
       datasourceid="CustomersSource" 
       autogeneratecolumns="False"
       autogenerateselectbutton="True"
       selectedindex="1"
       onselectedindexchanged="CustomersGridView_SelectedIndexChanged"
       onselectedindexchanging="CustomersGridView_SelectedIndexChanging"   
       runat="server" DataKeyNames="CustomerID">
                
         <Columns>
             <asp:BoundField DataField="CustomerID" 
                 HeaderText="CustomerID" 
                 InsertVisible="False" ReadOnly="True" 
                 SortExpression="CustomerID" />
             <asp:BoundField DataField="FirstName" 
                 HeaderText="FirstName" 
                 SortExpression="FirstName" />
             <asp:BoundField DataField="MiddleName" 
                 HeaderText="MiddleName" 
                 SortExpression="MiddleName" />
             <asp:BoundField DataField="LastName" 
                 HeaderText="LastName" 
                 SortExpression="LastName" />
             <asp:BoundField DataField="Phone" 
                 HeaderText="Phone" 
                 SortExpression="Phone" />
         </Columns>
                
       <selectedrowstyle backcolor="LightCyan"
         forecolor="DarkBlue"
         font-bold="true"/>  
                
     </asp:gridview>
            
      <br/>
            
      <asp:label id="MessageLabel"
        forecolor="Red"
        runat="server"/>
            
      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="CustomersSource"
        selectcommand="SELECT CustomerID, FirstName, MiddleName, LastName, Phone FROM SalesLT.Customer"
        connectionstring="<%$ ConnectionStrings:AdventureWorksLTConnectionString %>" 
        runat="server"/>
            
    </form>

  </body>
</html>

Keterangan

Peristiwa SelectedIndexChanging dimunculkan saat tombol Pilih baris diklik, tetapi sebelum GridView kontrol menangani operasi pilih. Ini memungkinkan Anda untuk menyediakan metode penanganan peristiwa yang melakukan rutinitas kustom, seperti membatalkan operasi pemilihan, setiap kali peristiwa ini terjadi.

Catatan

Kejadian ini tidak dinaikkan ketika Anda mengatur SelectedIndex properti secara terprogram.

Objek GridViewSelectEventArgs diteruskan ke metode penanganan peristiwa, yang memungkinkan Anda menentukan indeks baris yang dipilih oleh pengguna dan untuk menunjukkan bahwa operasi pemilihan harus dibatalkan. Untuk membatalkan operasi pemilihan, atur Cancel properti objek ke GridViewSelectEventArgstrue.

Untuk informasi selengkapnya tentang cara menangani peristiwa, lihat Menangani dan Menaikkan Peristiwa.

Berlaku untuk

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