SqlDataSourceCommandEventHandler Delegera
Definition
Viktigt
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Representerar den metod som ska hantera Updatingkontrollens , Insertingoch Deleting -händelser SqlDataSource .
public delegate void SqlDataSourceCommandEventHandler(System::Object ^ sender, SqlDataSourceCommandEventArgs ^ e);
public delegate void SqlDataSourceCommandEventHandler(object sender, SqlDataSourceCommandEventArgs e);
type SqlDataSourceCommandEventHandler = delegate of obj * SqlDataSourceCommandEventArgs -> unit
Public Delegate Sub SqlDataSourceCommandEventHandler(sender As Object, e As SqlDataSourceCommandEventArgs)
Parametrar
- sender
- Object
Källan till händelsen, SqlDataSource kontrollen.
En SqlDataSourceCommandEventArgs som innehåller händelsedata.
Exempel
Följande kodexempel visar hur du hanterar Inserting händelsen för att utföra eventuella förbearbetningssteg, till exempel att lägga till en parameter i DbCommand objektet som ingår i SqlDataSourceCommandEventArgs för att avbilda värdet för en utdataparameter innan en databasåtgärd utförs. I det här exemplet utförs en infogning av en DetailsView kontroll i ett klassiskt huvudinformationsscenario med hjälp av en lagrad procedur. Värdet för utdataparametern, som representerar den primära nyckeln för den nyligen infogade raden, undersöks när Inserted händelsen utlöses när åtgärden har slutförts.
<%@Page Language="C#" %>
<%@Import Namespace="System.Data" %>
<%@Import Namespace="System.Data.Common" %>
<%@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 On_Inserting(Object sender, SqlDataSourceCommandEventArgs e) {
SqlParameter insertedKey = new SqlParameter("@PK_New", SqlDbType.Int);
insertedKey.Direction = ParameterDirection.Output;
e.Command.Parameters.Add(insertedKey);
}
private void On_Inserted(Object sender, SqlDataSourceStatusEventArgs e) {
DbCommand command = e.Command;
// The label displays the primary key of the recently inserted row.
Label1.Text = command.Parameters["@PK_New"].Value.ToString();
// Force a refresh after the data is inserted.
GridView1.DataBind();
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:GridView
id="GridView1"
runat="server"
AutoGenerateColumns="False"
DataKeyNames="EmployeeID"
DataSourceID="SqlDataSource1">
<columns>
<asp:BoundField HeaderText="First Name" DataField="FirstName" />
<asp:BoundField HeaderText="Last Name" DataField="LastName" />
<asp:BoundField HeaderText="Title" DataField="Title" />
<asp:ButtonField ButtonType="Link" CommandName="Select" Text="Details..." />
</columns>
</asp:GridView>
<asp:SqlDataSource
id="SqlDataSource1"
runat="server"
ConnectionString="<%$ ConnectionStrings:MyNorthwind %>"
SelectCommand="SELECT EmployeeID,FirstName,LastName,Title FROM Employees">
</asp:SqlDataSource>
<hr />
<asp:DetailsView
id="DetailsView1"
runat="server"
DataSourceID="SqlDataSource2"
AutoGenerateRows="False"
AutoGenerateInsertButton="True">
<fields>
<asp:BoundField HeaderText="First Name" DataField="FirstName" ReadOnly="False"/>
<asp:BoundField HeaderText="Last Name" DataField="LastName" ReadOnly="False"/>
<asp:TemplateField HeaderText="Title">
<ItemTemplate>
<asp:DropDownList
id="TitleDropDownList"
runat="server"
selectedvalue="<%# Bind('Title') %>" >
<asp:ListItem Selected="True">Sales Representative</asp:ListItem>
<asp:ListItem>Sales Manager</asp:ListItem>
<asp:ListItem>Vice President, Sales</asp:ListItem>
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField HeaderText="Notes" DataField="Notes" ReadOnly="False"/>
</fields>
</asp:DetailsView>
<asp:SqlDataSource
id="SqlDataSource2"
runat="server"
ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
SelectCommand="SELECT * FROM Employees"
InsertCommandType = "StoredProcedure"
InsertCommand="sp_insertemployee"
OnInserting="On_Inserting"
OnInserted ="On_Inserted"
FilterExpression="EmployeeID={0}">
<FilterParameters>
<asp:ControlParameter Name="EmployeeID" ControlId="GridView1" PropertyName="SelectedValue" />
</FilterParameters>
</asp:SqlDataSource>
<!--
-- An example sp_insertemployee stored procedure that returns
-- the primary key of the row that was inserted in an OUT parameter.
CREATE PROCEDURE sp_insertemployee
@FirstName nvarchar(10),
@LastName nvarchar(20) ,
@Title nvarchar(30),
@Notes nvarchar(200),
@PK_New int OUTPUT
AS
INSERT INTO Employees(FirstName,LastName,Title,Notes)VALUES (@FirstName,@LastName,@Title,@Notes)
SELECT @PK_New = @@IDENTITY
RETURN (1)
GO
-->
<asp:Label
id="Label1"
runat="server" />
</form>
</body>
</html>
<%@Page Language="VB" %>
<%@Import Namespace="System.Data" %>
<%@Import Namespace="System.Data.Common" %>
<%@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_Inserting(ByVal sender As Object, ByVal e As SqlDataSourceCommandEventArgs)
Dim insertedKey As SqlParameter
insertedKey = New SqlParameter("@PK_New", SqlDbType.Int)
insertedKey.Direction = ParameterDirection.Output
e.Command.Parameters.Add(insertedKey)
End Sub 'On_Inserting
Sub On_Inserted(ByVal sender As Object, ByVal e As SqlDataSourceStatusEventArgs)
Dim command As DbCommand
command = e.Command
' The label displays the primary key of the recently inserted row.
Label1.Text = command.Parameters("@PK_New").Value.ToString()
' Explicitly call DataBind to refresh the data
' and show the newly inserted row.
GridView1.DataBind()
End Sub 'On_Inserted
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:GridView
id="GridView1"
runat="server"
AutoGenerateColumns="False"
DataKeyNames="EmployeeID"
DataSourceID="SqlDataSource1">
<columns>
<asp:BoundField HeaderText="First Name" DataField="FirstName" />
<asp:BoundField HeaderText="Last Name" DataField="LastName" />
<asp:BoundField HeaderText="Title" DataField="Title" />
<asp:ButtonField ButtonType="Link" CommandName="Select" Text="Details..." />
</columns>
</asp:GridView>
<asp:SqlDataSource
id="SqlDataSource1"
runat="server"
ConnectionString="<%$ ConnectionStrings:MyNorthwind %>"
SelectCommand="SELECT EmployeeID,FirstName,LastName,Title FROM Employees">
</asp:SqlDataSource>
<hr />
<asp:DetailsView
id="DetailsView1"
runat="server"
DataSourceID="SqlDataSource2"
AutoGenerateRows="False"
AutoGenerateInsertButton="True">
<fields>
<asp:BoundField HeaderText="First Name" DataField="FirstName" ReadOnly="False"/>
<asp:BoundField HeaderText="Last Name" DataField="LastName" ReadOnly="False"/>
<asp:TemplateField HeaderText="Title">
<ItemTemplate>
<asp:DropDownList
id="TitleDropDownList"
runat="server"
selectedvalue="<%# Bind('Title') %>" >
<asp:ListItem Selected="True">Sales Representative</asp:ListItem>
<asp:ListItem>Sales Manager</asp:ListItem>
<asp:ListItem>Vice President, Sales</asp:ListItem>
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField HeaderText="Notes" DataField="Notes" ReadOnly="False"/>
</fields>
</asp:DetailsView>
<asp:SqlDataSource
id="SqlDataSource2"
runat="server"
ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
SelectCommand="SELECT * FROM Employees"
InsertCommandType = "StoredProcedure"
InsertCommand="sp_insertemployee"
OnInserting="On_Inserting"
OnInserted ="On_Inserted"
FilterExpression="EmployeeID={0}">
<FilterParameters>
<asp:ControlParameter Name="EmployeeID" ControlId="GridView1" PropertyName="SelectedValue" />
</FilterParameters>
</asp:SqlDataSource>
<!--
-- An example sp_insertemployee stored procedure that returns
-- the primary key of the row that was inserted in an OUT parameter.
CREATE PROCEDURE sp_insertemployee
@FirstName nvarchar(10),
@LastName nvarchar(20) ,
@Title nvarchar(30),
@Notes nvarchar(200),
@PK_New int OUTPUT
AS
INSERT INTO Employees(FirstName,LastName,Title,Notes)VALUES (@FirstName,@LastName,@Title,@Notes)
SELECT @PK_New = @@IDENTITY
RETURN (1)
GO
-->
<asp:Label
id="Label1"
runat="server" />
</form>
</body>
</html>
I följande kodexempel visas hur du hanterar händelsen RowUpdating som genereras av GridView kontrollen för att eventuellt avbryta en databasåtgärd som utförs av en SqlDataSource kontroll som är associerad med GridView kontrollen.
<%@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">
// Set helper text and cancel the update if the values submitted to update the row
// do not meet requirements.
private void OnRowUpdatingHandler(Object source, GridViewUpdateEventArgs e) {
// You can examine the values submitted by the user and perform additional
// processing as required.
if (e.OldValues[0].Equals("Nancy")) {
e.Cancel = true;
Label1.Text="This Row is Not Updatable!";
}
}
// Ensure any helper text is cleared.
private void OnRowCancellingHandler(Object source, GridViewCancelEditEventArgs e) {
Label1.Text="";
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<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 EmployeeID,FirstName,LastName,Title FROM Employees"
UpdateCommand="Update Employees SET FirstName=@FirstName,LastName=@LastName,Title=@Title WHERE EmployeeID=@EmployeeID">
</asp:SqlDataSource>
<asp:GridView
id="GridView1"
runat="server"
AutoGenerateColumns="False"
DataKeyNames="EmployeeID"
AutoGenerateEditButton="True"
DataSourceID="SqlDataSource1"
OnRowUpdating="OnRowUpdatingHandler"
OnRowCancelingEdit="OnRowCancellingHandler">
<columns>
<asp:BoundField HeaderText="First Name" DataField="FirstName" />
<asp:BoundField HeaderText="Last Name" DataField="LastName" />
<asp:BoundField HeaderText="Title" DataField="Title" />
</columns>
</asp:GridView>
<asp:Label
id="Label1"
runat="server">
</asp:Label>
</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">
' Set helper text and cancel the update if the values submitted to update the row
' do not meet requirements.
Sub OnRowUpdatingHandler(ByVal source As Object, ByVal e As GridViewUpdateEventArgs)
If e.OldValues(0).Equals("Nancy") Then
e.Cancel = "True"
Label1.Text="This Row is Not Updatable!"
End If
End Sub 'OnRowUpdatingHandler
' Ensure any helper text is cleared.
Sub OnRowCancellingHandler(ByVal source As Object, ByVal e As GridViewCancelEditEventArgs)
Label1.Text=""
End Sub 'OnRowCancellingHandler
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<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 EmployeeID,FirstName,LastName,Title FROM Employees"
UpdateCommand="Update Employees SET FirstName=@FirstName,LastName=@LastName,Title=@Title WHERE EmployeeID=@EmployeeID">
</asp:SqlDataSource>
<asp:GridView
id="GridView1"
runat="server"
AutoGenerateColumns="False"
DataKeyNames="EmployeeID"
AutoGenerateEditButton="True"
DataSourceID="SqlDataSource1"
OnRowUpdating="OnRowUpdatingHandler"
OnRowCancelingEdit="OnRowCancellingHandler">
<columns>
<asp:BoundField HeaderText="First Name" DataField="FirstName" />
<asp:BoundField HeaderText="Last Name" DataField="LastName" />
<asp:BoundField HeaderText="Title" DataField="Title" />
</columns>
</asp:GridView>
<asp:Label
id="Label1"
runat="server">
</asp:Label>
</form>
</body>
</html>
Kommentarer
När du skapar ett SqlDataSourceCommandEventHandler ombud identifierar du den metod som ska hantera händelsen. Om du vill associera händelsen med händelsehanteraren lägger du till en instans av ombudet till händelsen. Händelsehanteraren anropas när händelsen inträffar, såvida du inte tar bort ombudet. Mer information om hur du hanterar händelser finns i Hantera och höja händelser.
Tilläggsmetoder
| Name | Description |
|---|---|
| GetMethodInfo(Delegate) |
Hämtar ett objekt som representerar den metod som representeras av det angivna ombudet. |