SqlDataSource.Deleting 事件 (System.Web.UI.WebControls)

Deleting 事件

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語言篩選

本頁僅適用於

Microsoft Visual Studio 2008/.NET Framework 3.5

其他版本也適用於下列軟體：

.NET Framework 類別庫

SqlDataSource..::.Deleting 事件

更新：2007 年 11 月

在刪除作業之前發生。

命名空間： System.Web.UI.WebControls
組件： System.Web (在 System.Web.dll 中)

語法

Visual Basic (宣告)

Public Event Deleting As SqlDataSourceCommandEventHandler

Visual Basic (使用方式)

Dim instance As SqlDataSource
Dim handler As SqlDataSourceCommandEventHandler

AddHandler instance.Deleting, handler

public event SqlDataSourceCommandEventHandler Deleting

Visual C++

public:
 event SqlDataSourceCommandEventHandler^ Deleting {
    void add (SqlDataSourceCommandEventHandler^ value);
    void remove (SqlDataSourceCommandEventHandler^ value);
}

/** @event */
public void add_Deleting (SqlDataSourceCommandEventHandler value)
/** @event */
public void remove_Deleting (SqlDataSourceCommandEventHandler value)

JScript

JScript 不支援事件。

ASP.NET

<asp:SqlDataSource OnDeleting="SqlDataSourceCommandEventHandler" />

備註

處理 Deleting 事件，執行您應用程式特定的其他初始設定作業，以驗證參數的值或在 SqlDataSource 控制項執行刪除作業之前，變更參數值。

呼叫事件處理常式委派時，尚未開啟基礎資料來源的連接。因此，您無法直接取消該作業，即使是在 SqlDataSourceCommandEventArgs 物件公開的 DbCommand 物件上呼叫 Cancel 方法。不過，您可以將 SqlDataSourceCommandEventArgs 物件的 Cancel 屬性設為 true，以取消資料庫作業。

如需處理事件的詳細資訊，請參閱使用事件。

範例

在下列程式碼中，示範了如何處理在 Delete 作業之前引發的 Deleting 事件。由於這個程式碼範例會刪除 Northwind 資料庫的資料，所以會加入 OnDeleting 處理常式，以在執行 Delete 作業之前，先嘗試將資料庫備份至磁碟。

Visual Basic

<%@Page  Language="VB" %>
<%@Import Namespace="System.Data.SqlClient" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
 Sub On_Record_Deleting(ByVal source As Object, ByVal e As SqlDataSourceCommandEventArgs)
     ' Cancel the delete operation if the checkbox is not checked.
     If Not CheckBox1.Checked 
            e.Cancel = True
            Label1.Text = "The command was cancelled because the CheckBox was not checked."
     End If

End Sub 'On_Record_Deleting

Sub On_Record_Deleted(ByVal source As Object, ByVal e As SqlDataSourceStatusEventArgs)
    Label1.Text = e.AffectedRows & " row(s) were deleted"

End Sub

</script>

<html  >
  <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="form1" runat="server">

        <asp:SqlDataSource
            id="SqlDataSource1"
            runat="server"
            DataSourceMode="DataSet"
            ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
            SelectCommand="SELECT * FROM Orders"
            DeleteCommand="DELETE FROM [Order Details] WHERE OrderID=@OrderID;DELETE FROM Orders WHERE OrderID=@OrderID;"
            OnDeleting="On_Record_Deleting"
            OnDeleted="On_Record_Deleted">
        </asp:SqlDataSource>
        <br />

       <asp:CheckBox 
         id="CheckBox1" 
         runat="server"
         autopostback="true"
         text="Check To Delete Data" />
        <br />
        <br />

        <asp:GridView
            id="GridView1"
            runat="server"
            AutoGenerateColumns="False"
            DataKeyNames="OrderID"
            AutoGenerateDeleteButton="True"
            AllowPaging="True"
            PageSize="20"
            DataSourceID="SqlDataSource1">
            <Columns>
                <asp:BoundField HeaderText="Order ID" DataField="OrderID" />
                <asp:BoundField HeaderText="Customer" DataField="CustomerID" />
                <asp:BoundField HeaderText="Order Placed" DataField="OrderDate" />
                <asp:BoundField HeaderText="Order Shipped" DataField="ShippedDate" />
            </Columns>
        </asp:GridView>

        <asp:Label
            id="Label1"
            runat="server">
        </asp:Label>

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

<%@Page  Language="C#" %>
<%@Import Namespace="System.Data.SqlClient" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
private void OnRecordDeleting(Object source, SqlDataSourceCommandEventArgs e) {    
    // Cancel the delete operation if the checkbox is not checked.
    if (! CheckBox1.Checked) {
        e.Cancel = true;
        Label1.Text = "The command was cancelled because the CheckBox was not checked.";
    }
 }

private void OnRecordDeleted(object source, SqlDataSourceStatusEventArgs e) {
    Label1.Text = e.AffectedRows + " row(s) were deleted";
}
</script>

<html  >
  <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="form1" runat="server">
        <asp:SqlDataSource
            id="SqlDataSource1"
            runat="server"
            DataSourceMode="DataSet"
            ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
            SelectCommand="SELECT * FROM Orders"            
            DeleteCommand="DELETE FROM [Order Details] WHERE OrderID=@OrderID;DELETE FROM Orders WHERE OrderID=@OrderID;"
            OnDeleting="OnRecordDeleting"
            OnDeleted="OnRecordDeleted">
        </asp:SqlDataSource>
        <br />
       <asp:CheckBox 
         id="CheckBox1" 
         runat="server"
         autopostback="true"
         text="Check To Delete Data" />
        <br />
        <br />

        <asp:GridView
            id="GridView1"
            runat="server"
            AutoGenerateColumns="False"
            DataKeyNames="OrderID"
            AutoGenerateDeleteButton="True"
            AllowPaging="True"
            PageSize="20"
            DataSourceID="SqlDataSource1">
            <Columns>
                <asp:BoundField HeaderText="Order ID" DataField="OrderID" />
                <asp:BoundField HeaderText="Customer" DataField="CustomerID" />
                <asp:BoundField HeaderText="Order Placed" DataField="OrderDate" />
                <asp:BoundField HeaderText="Order Shipped" DataField="ShippedDate" />
            </Columns>
        </asp:GridView>

        <asp:Label
            id="Label1"
            runat="server">
        </asp:Label>

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

<%@Page  Language="VJ#" %>
<%@Import Namespace="System.Data.SqlClient" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
     private void OnRecordDeleting(Object source, 
        SqlDataSourceCommandEventArgs e)
    {
        // Because this example actually deletes data from the Northwind
        // database, provide a way for users to recover any deleted records.
        SqlConnection cxn = new SqlConnection(
            "Data Source=localhost;Integrated Security=SSPI;" 
            + "Initial Catalog=Northwind;Connect Timeout=15");

        try {
            cxn.Open();
            SqlCommand backup = new SqlCommand();
            backup.set_Connection (cxn);
            backup.set_CommandText(
                " USE master " + " EXEC sp_addumpdevice 'disk','Northwind_1'," 
                + "'c:\\temp\\Northwind_1.dat'" 
                + " BACKUP DATABASE Northwind TO Northwind_1");
            backup.ExecuteNonQuery();
        }
        catch (SqlException se) {
            // Handle an exception thrown if the device already exists.
            Label1.set_Text("An error occurred while backing up your " 
                + "database. Please check the SQL logs.");
        }
        finally {
            // Always release the connection.
            cxn.Dispose();
        }
        Label1.set_Text("A record has been deleted. To recover your data, " 
            + "restore the database from the " 
            + "database backup named Northwind_1.dat located on the database " 
            + "server in c:\\temp.");
    } //OnRecordDeleting
</script>

<html  >
    <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
        <form id="form1" runat="server">

            <asp:SqlDataSource
                id="SqlDataSource1"
                runat="server"
                DataSourceMode="DataSet"
                ConnectionString="Data Source=localhost;Integrated Security=SSPI;Initial Catalog=Northwind;"
                SelectCommand="SELECT * FROM Orders"
                DeleteCommand="DELETE FROM [Order Details] WHERE OrderID=@OrderID;DELETE FROM Orders WHERE OrderID=@OrderID;"
                OnDeleting="OnRecordDeleting">
            </asp:SqlDataSource>

            <asp:GridView
                id="GridView1"
                runat="server"
                AutoGenerateColumns="False"
                DataKeyNames="OrderID"
                AutoGenerateDeleteButton="True"
                AllowPaging="True"
                PageSize="20"
                DataSourceID="SqlDataSource1">
                <Columns>
                    <asp:BoundField HeaderText="Order ID" DataField="OrderID" />
                    <asp:BoundField HeaderText="Customer" DataField="CustomerID" />
                    <asp:BoundField HeaderText="Order Placed" DataField="OrderDate" />
                    <asp:BoundField HeaderText="Order Shipped" DataField="ShippedDate" />
                </Columns>
            </asp:GridView>

            <asp:Label
                id="Label1"
                runat="server">
            </asp:Label>

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

平台

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

.NET Framework 和 .NET Compact Framework 並不支援各種平台的所有版本。如需支援平台版本的相關資訊，請參閱 .NET Framework 系統需求。

版本資訊