DataGridCommandEventArgs.CommandSource Proprietà
Definizione
Importante
Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.
Ottiene l'origine del comando.
public:
property System::Object ^ CommandSource { System::Object ^ get(); };public object CommandSource { get; }member this.CommandSource : objPublic ReadOnly Property CommandSource As ObjectValore della proprietà
Origine del comando.
Esempio
Nell'esempio di codice seguente viene illustrato come determinare l'origine del comando usando la CommandSource proprietà .
<%@ page language="C#" %>
<%@ import namespace="System.Data" %>
<%@ 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">
void Page_Load(Object sender, EventArgs e)
{
// Call the BindGrid helper method to bind the
// DataGrid control to the data source the first
// time the page is loaded.
if(!IsPostBack)
{
BindGrid();
}
}
void BindGrid()
{
// Declare the connection string and query string.
// This example uses Microsoft SQL Server and connects
// to the Northwind sample database.
String connectionString = "server=localhost;database=NorthWind;Integrated Security=SSPI";
String queryString = "Select [FirstName],[LastName],[Title] From [Employees]";
// Run the query and display the results.
DataSet ds = RunQuery(connectionString, queryString);
if(ds != null)
{
ItemsGrid.DataSource = ds;
ItemsGrid.DataBind();
Message.Text = "";
}
else
{
Message.Text = "No records found.";
}
}
DataSet RunQuery(String connectionString, String queryString)
{
SqlConnection connection = new SqlConnection(connectionString);
SqlDataAdapter adapter;
DataSet ds;
try
{
// Run the query and create the DataSet object.
ds = new DataSet();
adapter = new SqlDataAdapter(queryString, connection);
adapter.Fill(ds);
}
catch(Exception ex)
{
// Display an error message.
Message.Text = "Unable to query data source.";
ds = null;
}
finally
{
connection.Close();
}
return ds;
}
void ItemsGrid_ItemCommand(Object sender, DataGridCommandEventArgs e)
{
// Use the CommandSource property to retrieve the LinkButton
// control that raised the event.
LinkButton selectButton = (LinkButton)e.CommandSource;
// Display the desciption for the job title.
Message.Text = selectButton.Text + " - ";
switch (selectButton.Text)
{
case "Sales Representative":
Message.Text += "Sells products to customers.";
break;
case "Vice President, Sales":
Message.Text += "Manages the sales division.";
break;
case "Sales Manager":
Message.Text += "Manages a sales team.";
break;
case "Inside Sales Coordinator":
Message.Text += "Coordinates cross team communications.";
break;
default:
Message.Text += "To be determined.";
break;
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DataGridCommandEventArgs CommandSource Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGridCommandEventArgs CommandSource Example</h3>
<asp:datagrid
id="ItemsGrid"
autogeneratecolumns="false"
onitemcommand="ItemsGrid_ItemCommand"
runat="server">
<columns>
<asp:BoundColumn DataField="FirstName"
headertext="First Name"/>
<asp:BoundColumn DataField="LastName"
headertext="Last Name"/>
<asp:buttoncolumn buttontype="LinkButton"
datatextfield="Title"
headertext="Title"/>
</columns>
</asp:datagrid>
<br/><br/>
<asp:label id="Message"
runat="server"/>
</form>
</body>
</html>
<%@ page language="VB" %>
<%@ import namespace="System.Data" %>
<%@ 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 Page_Load(ByVal sender As Object, ByVal e As EventArgs)
' Call the BindGrid helper method to bind the
' DataGrid control to the data source the first
' time the page is loaded.
If Not IsPostBack Then
BindGrid()
End If
End Sub
Sub BindGrid()
' Declare the connection string and query string.
' This example uses Microsoft SQL Server and connects
' to the Northwind sample database.
Dim connectionString As String = "server=localhost;database=NorthWind;Integrated Security=SSPI"
Dim queryString As String = "Select [FirstName],[LastName],[Title] From [Employees]"
' Run the query and display the results.
Dim ds As DataSet = RunQuery(connectionString, queryString)
If ds IsNot Nothing Then
ItemsGrid.DataSource = ds
ItemsGrid.DataBind()
Message.Text = ""
Else
Message.Text = "No records found."
End If
End Sub
Function RunQuery(ByVal connectionString As String, ByVal queryString As String) As DataSet
Dim connection As New SqlConnection(connectionString)
Dim adapter As SqlDataAdapter
Dim ds As DataSet
Try
' Run the query and create the DataSet object.
ds = New DataSet()
adapter = New SqlDataAdapter(queryString, connection)
adapter.Fill(ds)
Catch ex As Exception
' Display an error message.
Message.Text = "Unable to query data source."
ds = Nothing
Finally
Connection.Close()
End Try
Return ds
End Function
Sub ItemsGrid_ItemCommand(ByVal sender As Object, ByVal e As DataGridCommandEventArgs)
' Use the CommandSource property to retrieve the LinkButton
' control that raised the event.
Dim selectButton As LinkButton = CType(e.CommandSource, LinkButton)
' Display the desciption for the job title.
Message.Text = selectButton.Text & " - "
Select Case (selectButton.Text)
Case "Sales Representative"
Message.Text &= "Sells products to customers."
Case "Vice President, Sales"
Message.Text &= "Manages the sales division."
Case "Sales Manager"
Message.Text &= "Manages a sales team."
Case "Inside Sales Coordinator"
Message.Text &= "Coordinates cross team communications."
Case Else
Message.Text &= "To be determined."
End Select
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DataGridCommandEventArgs CommandSource Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGridCommandEventArgs CommandSource Example</h3>
<asp:datagrid
id="ItemsGrid"
autogeneratecolumns="false"
onitemcommand="ItemsGrid_ItemCommand"
runat="server">
<columns>
<asp:BoundColumn DataField="FirstName"
headertext="First Name"/>
<asp:BoundColumn DataField="LastName"
headertext="Last Name"/>
<asp:buttoncolumn buttontype="LinkButton"
datatextfield="Title"
headertext="Title"/>
</columns>
</asp:datagrid>
<br/><br/>
<asp:label id="Message"
runat="server"/>
</form>
</body>
</html>
Commenti
Utilizzare la CommandSource proprietà per determinare l'origine del comando che ha generato l'evento. Questa proprietà viene comunemente usata per determinare quale comando ha generato l'evento.