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DataListCommandEventHandler 代理人

定義

表示處理 CancelCommand 控制項的 DeleteCommandEditCommandItemCommandUpdateCommandDataList 事件的方法。

public delegate void DataListCommandEventHandler(System::Object ^ source, DataListCommandEventArgs ^ e);
public delegate void DataListCommandEventHandler(object source, DataListCommandEventArgs e);
type DataListCommandEventHandler = delegate of obj * DataListCommandEventArgs -> unit
Public Delegate Sub DataListCommandEventHandler(source As Object, e As DataListCommandEventArgs)

參數

source
Object

事件的來源。

e
DataListCommandEventArgs

DataListCommandEventArgs,其中包含事件資料。

範例

下列範例示範如何定義 控制項之 EditCommandUpdateCommandCancelCommandDeleteCommand 事件的 DataList 事件處理常式。 這個範例會以宣告方式指定事件處理常式,為控制項上的 DataList 每個命令屬性設定事件處理常式。


<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>DataList Edit Example</title>
<script runat="server">

      // The Cart and CartView objects temporarily store the data source
      // for the DataList control while the page is being processed.
      DataTable Cart = new DataTable();
      DataView CartView;   
 
      void Page_Load(Object sender, EventArgs e) 
      {
 
         // With a database, use an select query to retrieve the data. 
         // Because the data source in this example is an in-memory
         // DataTable, retrieve the data from session state if it exists;
         // otherwise, create the data source.
         GetSource();

         // The DataList control maintains state between posts to the server;
         // it only needs to be bound to a data source the first time the
         // page is loaded or when the data source is updated.
         if (!IsPostBack)
         {

            BindList();

         }
                   
      }

      void BindList() 
      {

         // Set the data source and bind to the DataList control.
         ItemsList.DataSource = CartView;
         ItemsList.DataBind();

      }

      void GetSource()
      {

         // For this example, the data source is a DataTable that 
         // is stored in session state. If the data source does not exist,
         // create it; otherwise, load the data.
         if (Session["ShoppingCart"] == null) 
         {     

            // Create the sample data.
            DataRow dr;  
 
            // Define the columns of the table.
            Cart.Columns.Add(new DataColumn("Qty", typeof(Int32)));
            Cart.Columns.Add(new DataColumn("Item", typeof(String)));
            Cart.Columns.Add(new DataColumn("Price", typeof(Double)));

            // Store the table in session state to persist its values 
            // between posts to the server.
            Session["ShoppingCart"] = Cart;
             
            // Populate the DataTable with sample data.
            for (int i = 1; i <= 9; i++) 
            {
               dr = Cart.NewRow();
               if (i % 2 != 0)
               {
                  dr[0] = 2;
               }
               else
               {
                  dr[0] = 1;
               }
               dr[1] = "Item " + i.ToString();
               dr[2] = (1.23 * (i + 1));
               Cart.Rows.Add(dr);
            }

         } 

         else
         {

            // Retrieve the sample data from session state.
            Cart = (DataTable)Session["ShoppingCart"];

         }         
 
         // Create a DataView and specify the field to sort by.
         CartView = new DataView(Cart);
         CartView.Sort="Item";

         return;

      }

      void Edit_Command(Object sender, DataListCommandEventArgs e) 
      {

         // Set the EditItemIndex property to the index of the item clicked
         // in the DataList control to enable editing for that item. Be sure
         // to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = e.Item.ItemIndex;
         BindList();

      }

      void Cancel_Command(Object sender, DataListCommandEventArgs e) 
      {

         // Set the EditItemIndex property to -1 to exit editing mode. Be sure
         // to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = -1;
         BindList();

      }

      void Delete_Command(Object sender, DataListCommandEventArgs e) 
      { 

         // Retrieve the name of the item to remove.
         String item = ((Label)e.Item.FindControl("ItemLabel")).Text;

         // Filter the CartView for the selected item and remove it from
         // the data source.
         CartView.RowFilter = "Item='" + item + "'";
         if (CartView.Count > 0) 
         {
            CartView.Delete(0);
         }
         CartView.RowFilter = "";

         // Set the EditItemIndex property to -1 to exit editing mode. Be sure
         // to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = -1;
         BindList();

      }

      void Update_Command(Object sender, DataListCommandEventArgs e) 
      {

         // Retrieve the updated values from the selected item.
         String item = ((Label)e.Item.FindControl("ItemLabel")).Text;
         String qty = ((TextBox)e.Item.FindControl("QtyTextBox")).Text;
         String price = ((TextBox)e.Item.FindControl("PriceTextBox")).Text;

         // With a database, use an update command to update the data.
         // Because the data source in this example is an in-memory 
         // DataTable, delete the old row and replace it with a new one.

         // Filter the CartView for the selected item and remove it from
         // the data source.
         CartView.RowFilter = "Item='" + item + "'";
         if (CartView.Count > 0)
         {
            CartView.Delete(0);
         }
         CartView.RowFilter = "";

         // ***************************************************************
         // Insert data validation code here. Make sure to validate the
         // values entered by the user before converting to the appropriate
         // data types and updating the data source.
         // ***************************************************************

         // Add a new entry to replace the previous item.
         DataRow dr = Cart.NewRow();
         dr[0] = qty;
         dr[1] = item;
         // If necessary, remove the '$' character from the price before
         // converting the price to a Double.
         if(price[0] == '$')
         {
            dr[2] = Convert.ToDouble(price.Substring(1));
         }
         else
         {
            dr[2] = Convert.ToDouble(price);
         }
         Cart.Rows.Add(dr);

         // Set the EditItemIndex property to -1 to exit editing mode. 
         // Be sure to rebind the DataList to the data source to refresh
         // the control.
         ItemsList.EditItemIndex = -1;
         BindList();

      }

   </script>

</head>
<body>

   <form id="form1" runat="server">

      <h3>DataList Edit Example</h3>

      Click <b>Edit</b> to edit the values of the item.

      <br /><br />
       
      <asp:DataList id="ItemsList"
           GridLines="Both"
           RepeatColumns="3"
           RepeatDirection="Horizontal"
           CellPadding="3"
           CellSpacing="0"
           OnEditCommand="Edit_Command"
           OnUpdateCommand="Update_Command"
           OnDeleteCommand="Delete_Command"
           OnCancelCommand="Cancel_Command"
           runat="server">

         <HeaderStyle BackColor="#aaaadd">
         </HeaderStyle>

         <AlternatingItemStyle BackColor="Gainsboro">
         </AlternatingItemStyle>

         <EditItemStyle BackColor="yellow">
         </EditItemStyle>

         <HeaderTemplate>

            Items

         </HeaderTemplate>
         
         <ItemTemplate>

            Item:
            <%# DataBinder.Eval(Container.DataItem, "Item") %> 

            <br />

            Quantity:
            <%# DataBinder.Eval(Container.DataItem, "Qty") %>

            <br />

            Price:
            <%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>

            <br />

            <asp:LinkButton id="EditButton" 
                 Text="Edit" 
                 CommandName="Edit"
                 runat="server"/>

         </ItemTemplate>
              
         <EditItemTemplate>

            Item:
            <asp:Label id="ItemLabel" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Item") %>' 
                 runat="server"/>

            <br />

            Quantity:
            <asp:TextBox id="QtyTextBox" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Qty") %>' 
                 runat="server"/>

            <br />

            Price:
            <asp:TextBox id="PriceTextBox" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>' 
                 runat="server"/>

            <br />

            <asp:LinkButton id="UpdateButton" 
                 Text="Update" 
                 CommandName="Update" 
                 runat="server"/>

            <asp:LinkButton id="DeleteButton" 
                 Text="Delete" 
                 CommandName="Delete" 
                 runat="server"/>

            <asp:LinkButton id="CancelButton" 
                 Text="Cancel" 
                 CommandName="Cancel" 
                 runat="server"/>

         </EditItemTemplate>

      </asp:DataList>

   </form>

</body>
</html>

<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>DataList Edit Example</title>
<script runat="server">

      ' The Cart and CartView objects temporarily store the data source
      ' for the DataList control while the page is being processed.
      Dim Cart As DataTable = New DataTable()
      Dim CartView As DataView
 
      Sub Page_Load(sende As Object, e As EventArgs) 
 
         ' With a database, use an select query to retrieve the data.
         ' Because the data source in this example is an in-memory
         ' DataTable, retrieve the data from session state if it exists;
         ' otherwise, create the data source.
         GetSource()

         ' The DataGrid control maintains state between posts to the server;
         ' it only needs to be bound to a data source the first time the
         ' page is loaded or when the data source is updated.
         If Not IsPostBack Then

            BindList()

         End If
                   
      End Sub

      Sub BindList() 

         ' Set the data source and bind to the DataList control.
         ItemsList.DataSource = CartView
         ItemsList.DataBind()

      End Sub

      Sub GetSource()

         ' For this example, the data source is a DataTable that
         ' is stored in session state. If the data source does not exist,
         ' create it; otherwise, load the data.
         If Session("ShoppingCart") Is Nothing Then 

            ' Create the sample data.
            Dim dr As DataRow  
 
            ' Define the columns of the table.
            Cart.Columns.Add(new DataColumn("Qty", GetType(Int32)))
            Cart.Columns.Add(new DataColumn("Item", GetType(String)))
            Cart.Columns.Add(new DataColumn("Price", GetType(Double)))

            ' Store the table in session state to persist its values
            ' between posts to the server.
            Session("ShoppingCart") = Cart
             
            ' Populate the DataTable with sample data.
            Dim i As Integer

            For i = 1 To 9 
            
               dr = Cart.NewRow()
               If (i Mod 2) <> 0 Then

                  dr(0) = 2
               
               Else
               
                  dr(0) = 1
               
               End If

               dr(1) = "Item " & i.ToString()
               dr(2) = (1.23 * (i + 1))
               Cart.Rows.Add(dr)
            
            Next i

         Else

            ' Retrieve the sample data from session state.
            Cart = CType(Session("ShoppingCart"), DataTable)

         End If         
 
         ' Create a DataView and specify the field to sort by.
         CartView = New DataView(Cart)
         CartView.Sort="Item"

         Return

      End Sub

      Sub Edit_Command(sender As Object, e As DataListCommandEventArgs) 

         ' Set the EditItemIndex property to the index of the item clicked
         ' in the DataList control to enable editing for that item. Be sure
         ' to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = e.Item.ItemIndex
         BindList()

      End Sub

      Sub Cancel_Command(sender As Object, e As DataListCommandEventArgs) 

         ' Set the EditItemIndex property to -1 to exit editing mode. Be sure
         ' to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = -1
         BindList()

      End Sub

      Sub Delete_Command(sender As Object, e As DataListCommandEventArgs) 

         ' Retrieve the name of the item to remove.
         Dim item As String = (CType(e.Item.FindControl("ItemLabel"), Label)).Text

         ' Filter the CartView for the selected item and remove it from
         ' the data source.
         CartView.RowFilter = "Item='" & item & "'"
         If CartView.Count > 0 Then 
       
            CartView.Delete(0)
         
         End If
         CartView.RowFilter = ""

         ' Set the EditItemIndex property to -1 to exit editing mode. Be sure 
         ' to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = -1
         BindList()

      End Sub

      Sub Update_Command(sender As Object, e As DataListCommandEventArgs) 

         ' Retrieve the updated values from the selected item.
         Dim item As String = _
             (CType(e.Item.FindControl("ItemLabel"), Label)).Text
         Dim qty As String = _
             (CType(e.Item.FindControl("QtyTextBox"), TextBox)).Text
         Dim price As String = _
             (CType(e.Item.FindControl("PriceTextBox"), TextBox)).Text

         ' With a database, use an update command to update the data.
         ' Because the data source in this example is an in-memory 
         ' DataTable, delete the old row and replace it with a new one.

         ' Filter the CartView for the selected item and remove it from 
         ' the data source.
         CartView.RowFilter = "Item='" & item & "'"
         If CartView.Count > 0 Then 
       
            CartView.Delete(0)
         
         End If
         CartView.RowFilter = ""

         ' ***************************************************************
         ' Insert data validation code here. Make sure to validate the
         ' values entered by the user before converting to the appropriate
         ' data types and updating the data source.
         ' ***************************************************************

         ' Add a new entry to replace the previous item.
         Dim dr As DataRow = Cart.NewRow()
         dr(0) = qty
         dr(1) = item
         ' If necessary, remove the '$' character from the price before 
         ' converting the price to a Double.
         If price.Chars(0) = "$" Then

            dr(2) = Convert.ToDouble(price.Substring(1))

         Else

            dr(2) = Convert.ToDouble(price)
         
         End If

         Cart.Rows.Add(dr)

         ' Set the EditItemIndex property to -1 to exit editing mode. 
         ' Be sure to rebind the DataList to the data source to refresh 
         ' the control.
         ItemsList.EditItemIndex = -1
         BindList()

      End Sub

   </script>

</head>
<body>

   <form id="form1" runat="server">

      <h3>DataList Edit Example</h3>

      Click <b>Edit</b> to edit the values of the item.

      <br /><br />
       
      <asp:DataList id="ItemsList"
           GridLines="Both"
           RepeatColumns="3"
           RepeatDirection="Horizontal"
           CellPadding="3"
           CellSpacing="0"
           OnEditCommand="Edit_Command"
           OnUpdateCommand="Update_Command"
           OnDeleteCommand="Delete_Command"
           OnCancelCommand="Cancel_Command"
           runat="server">

         <HeaderStyle BackColor="#aaaadd">
         </HeaderStyle>

         <AlternatingItemStyle BackColor="Gainsboro">
         </AlternatingItemStyle>

         <EditItemStyle BackColor="yellow">
         </EditItemStyle>

         <HeaderTemplate>

            Items

         </HeaderTemplate>
         
         <ItemTemplate>

            Item:
            <%# DataBinder.Eval(Container.DataItem, "Item") %> 

            <br />

            Quantity:
            <%# DataBinder.Eval(Container.DataItem, "Qty") %>

            <br />

            Price:
            <%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>

            <br />

            <asp:LinkButton id="EditButton" 
                 Text="Edit" 
                 CommandName="Edit"
                 runat="server"/>

         </ItemTemplate>
              
         <EditItemTemplate>

            Item:
            <asp:Label id="ItemLabel" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Item") %>' 
                 runat="server"/>

            <br />

            Quantity:
            <asp:TextBox id="QtyTextBox" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Qty") %>' 
                 runat="server"/>

            <br />

            Price:
            <asp:TextBox id="PriceTextBox" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>' 
                 runat="server"/>

            <br />

            <asp:LinkButton id="UpdateButton" 
                 Text="Update" 
                 CommandName="Update" 
                 runat="server"/>

            <asp:LinkButton id="DeleteButton" 
                 Text="Delete" 
                 CommandName="Delete" 
                 runat="server"/>

            <asp:LinkButton id="CancelButton" 
                 Text="Cancel" 
                 CommandName="Cancel" 
                 runat="server"/>

         </EditItemTemplate>

      </asp:DataList>

   </form>

</body>
</html>

下列程式碼範例示範如何指定事件處理常式,並以程式設計方式將它們新增至 方法中的 Page_Load 事件。


<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>DataList Edit Example</title>
<script runat="server">

      // The Cart and CartView objects temporarily store the data source
      // for the DataList control while the page is being processed.
      DataTable Cart = new DataTable();
      DataView CartView;   
 
      void Page_Load(Object sender, EventArgs e) 
      {
 
         // With a database, use an select query to retrieve the data. 
         // Because the data source in this example is an in-memory
         // DataTable, retrieve the data from session state if it exists;
         // otherwise, create the data source.
         GetSource();

         // The DataList control maintains state between posts to the server;
         // it only needs to be bound to a data source the first time the
         // page is loaded or when the data source is updated.
         if (!IsPostBack)
         {

            BindList();

         }

         // Manually register the event-handling methods.
         ItemsList.EditCommand += 
             new DataListCommandEventHandler(this.Edit_Command);
         ItemsList.UpdateCommand += 
             new DataListCommandEventHandler(this.Update_Command);
         ItemsList.DeleteCommand += 
             new DataListCommandEventHandler(this.Delete_Command);
         ItemsList.CancelCommand += 
             new DataListCommandEventHandler(this.Cancel_Command);
                   
      }

      void BindList() 
      {

         // Set the data source and bind to the DataList control.
         ItemsList.DataSource = CartView;
         ItemsList.DataBind();

      }

      void GetSource()
      {

         // For this example, the data source is a DataTable that 
         // is stored in session state. If the data source does not exist,
         // create it; otherwise, load the data.
         if (Session["ShoppingCart"] == null) 
         {     

            // Create the sample data.
            DataRow dr;  
 
            // Define the columns of the table.
            Cart.Columns.Add(new DataColumn("Qty", typeof(Int32)));
            Cart.Columns.Add(new DataColumn("Item", typeof(String)));
            Cart.Columns.Add(new DataColumn("Price", typeof(Double)));

            // Store the table in session state to persist its values
            // between posts to the server.
            Session["ShoppingCart"] = Cart;
             
            // Populate the DataTable with sample data.
            for (int i = 1; i <= 9; i++) 
            {
               dr = Cart.NewRow();
               if (i % 2 != 0)
               {
                  dr[0] = 2;
               }
               else
               {
                  dr[0] = 1;
               }
               dr[1] = "Item " + i.ToString();
               dr[2] = (1.23 * (i + 1));
               Cart.Rows.Add(dr);
            }

         } 

         else
         {

            // Retrieve the sample data from session state.
            Cart = (DataTable)Session["ShoppingCart"];

         }         
 
         // Create a DataView and specify the field to sort by.
         CartView = new DataView(Cart);
         CartView.Sort="Item";

         return;

      }

      void Edit_Command(Object sender, DataListCommandEventArgs e) 
      {

         // Set the EditItemIndex property to the index of the item clicked
         // in the DataList control to enable editing for that item. Be sure
         // to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = e.Item.ItemIndex;
         BindList();

      }

      void Cancel_Command(Object sender, DataListCommandEventArgs e) 
      {

         // Set the EditItemIndex property to -1 to exit editing mode. Be sure
         // to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = -1;
         BindList();

      }

      void Delete_Command(Object sender, DataListCommandEventArgs e) 
      { 

         // Retrieve the name of the item to remove.
         String item = ((Label)e.Item.FindControl("ItemLabel")).Text;

         // Filter the CartView for the selected item and remove it from
         // the data source.
         CartView.RowFilter = "Item='" + item + "'";
         if (CartView.Count > 0) 
         {
            CartView.Delete(0);
         }
         CartView.RowFilter = "";

         // Set the EditItemIndex property to -1 to exit editing mode. Be sure
         // to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = -1;
         BindList();

      }

      void Update_Command(Object sender, DataListCommandEventArgs e) 
      {

         // Retrieve the updated values from the selected item.
         String item = ((Label)e.Item.FindControl("ItemLabel")).Text;
         String qty = ((TextBox)e.Item.FindControl("QtyTextBox")).Text;
         String price = ((TextBox)e.Item.FindControl("PriceTextBox")).Text;

         // With a database, use an update command to update the data.
         // Because the data source in this example is an in-memory 
         // DataTable, delete the old row and replace it with a new one.

         // Filter the CartView for the selected item and remove it from
         // the data source.
         CartView.RowFilter = "Item='" + item + "'";
         if (CartView.Count > 0)
         {
            CartView.Delete(0);
         }
         CartView.RowFilter = "";

         // ***************************************************************
         // Insert data validation code here. Make sure to validate the
         // values entered by the user before converting to the appropriate
         // data types and updating the data source.
         // ***************************************************************

         // Add a new entry to replace the previous item.
         DataRow dr = Cart.NewRow();
         dr[0] = qty;
         dr[1] = item;
         // If necessary, remove the '$' character from the price before
         // converting the price to a Double.
         if(price[0] == '$')
         {
            dr[2] = Convert.ToDouble(price.Substring(1));
         }
         else
         {
            dr[2] = Convert.ToDouble(price);
         }
         Cart.Rows.Add(dr);

         // Set the EditItemIndex property to -1 to exit editing mode. 
         // Be sure to rebind the DataList to the data source to refresh
         // the control.
         ItemsList.EditItemIndex = -1;
         BindList();

      }

   </script>

</head>
<body>

   <form id="form1" runat="server">

      <h3>DataList Edit Example</h3>

      Click <b>Edit</b> to edit the values of the item.

      <br /><br />
       
      <asp:DataList id="ItemsList"
           GridLines="Both"
           RepeatColumns="3"
           RepeatDirection="Horizontal"
           CellPadding="3"
           CellSpacing="0"
           runat="server">

         <HeaderStyle BackColor="#aaaadd">
         </HeaderStyle>

         <AlternatingItemStyle BackColor="Gainsboro">
         </AlternatingItemStyle>

         <EditItemStyle BackColor="yellow">
         </EditItemStyle>

         <HeaderTemplate>

            Items

         </HeaderTemplate>
         
         <ItemTemplate>

            Item:
            <%# DataBinder.Eval(Container.DataItem, "Item") %> 

            <br />

            Quantity:
            <%# DataBinder.Eval(Container.DataItem, "Qty") %>

            <br />

            Price:
            <%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>

            <br />

            <asp:LinkButton id="EditButton" 
                 Text="Edit" 
                 CommandName="Edit"
                 runat="server"/>

         </ItemTemplate>
              
         <EditItemTemplate>

            Item:
            <asp:Label id="ItemLabel" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Item") %>' 
                 runat="server"/>

            <br />

            Quantity:
            <asp:TextBox id="QtyTextBox" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Qty") %>' 
                 runat="server"/>

            <br />

            Price:
            <asp:TextBox id="PriceTextBox" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>' 
                 runat="server"/>

            <br />

            <asp:LinkButton id="UpdateButton" 
                 Text="Update" 
                 CommandName="Update" 
                 runat="server"/>

            <asp:LinkButton id="DeleteButton" 
                 Text="Delete" 
                 CommandName="Delete" 
                 runat="server"/>

            <asp:LinkButton id="CancelButton" 
                 Text="Cancel" 
                 CommandName="Cancel" 
                 runat="server"/>

         </EditItemTemplate>

      </asp:DataList>

   </form>

</body>
</html>

<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>DataList Edit Example</title>
<script runat="server">

      ' The Cart and CartView objects temporarily store the data source
      ' for the DataList control while the page is being processed.
      Dim Cart As DataTable = New DataTable()
      Dim CartView As DataView
 
      Sub Page_Load(sende As Object, e As EventArgs) 
 
         ' With a database, use an select query to retrieve the data.
         ' Because the data source in this example is an in-memory
         ' DataTable, retrieve the data from session state if it exists;
         ' otherwise, create the data source.
         GetSource()

         ' The DataGrid control maintains state between posts to the server;
         ' it only needs to be bound to a data source the first time the
         ' page is loaded or when the data source is updated.
         If Not IsPostBack Then

            BindList()

         End If

         ' Manually register the event-handling methods.
         AddHandler ItemsList.EditCommand, AddressOf Edit_Command
         AddHandler ItemsList.UpdateCommand, AddressOf Update_Command
         AddHandler ItemsList.DeleteCommand, AddressOf Delete_Command
         AddHandler ItemsList.CancelCommand, AddressOf Cancel_Command
                   
      End Sub

      Sub BindList() 

         ' Set the data source and bind to the DataList control.
         ItemsList.DataSource = CartView
         ItemsList.DataBind()

      End Sub

      Sub GetSource()

         ' For this example, the data source is a DataTable that
         ' is stored in session state. If the data source does not exist,
         ' create it; otherwise, load the data.
         If Session("ShoppingCart") Is Nothing Then 

            ' Create the sample data.
            Dim dr As DataRow  
 
            ' Define the columns of the table.
            Cart.Columns.Add(new DataColumn("Qty", GetType(Int32)))
            Cart.Columns.Add(new DataColumn("Item", GetType(String)))
            Cart.Columns.Add(new DataColumn("Price", GetType(Double)))

            ' Store the table in session state to persist its values
            ' between posts to the server.
            Session("ShoppingCart") = Cart
             
            ' Populate the DataTable with sample data.
            Dim i As Integer

            For i = 1 To 9 
            
               dr = Cart.NewRow()
               If (i Mod 2) <> 0 Then

                  dr(0) = 2
               
               Else
               
                  dr(0) = 1
               
               End If

               dr(1) = "Item " & i.ToString()
               dr(2) = (1.23 * (i + 1))
               Cart.Rows.Add(dr)
            
            Next i

         Else

            ' Retrieve the sample data from session state.
            Cart = CType(Session("ShoppingCart"), DataTable)

         End If         
 
         ' Create a DataView and specify the field to sort by.
         CartView = New DataView(Cart)
         CartView.Sort="Item"

         Return

      End Sub

      Sub Edit_Command(sender As Object, e As DataListCommandEventArgs) 

         ' Set the EditItemIndex property to the index of the item clicked
         ' in the DataList control to enable editing for that item. Be sure
         ' to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = e.Item.ItemIndex
         BindList()

      End Sub

      Sub Cancel_Command(sender As Object, e As DataListCommandEventArgs) 

         ' Set the EditItemIndex property to -1 to exit editing mode. Be sure
         ' to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = -1
         BindList()

      End Sub

      Sub Delete_Command(sender As Object, e As DataListCommandEventArgs) 

         ' Retrieve the name of the item to remove.
         Dim item As String = (CType(e.Item.FindControl("ItemLabel"), Label)).Text

         ' Filter the CartView for the selected item and remove it from 
         ' the data source.
         CartView.RowFilter = "Item='" & item & "'"
         If CartView.Count > 0 Then 
       
            CartView.Delete(0)
         
         End If
         CartView.RowFilter = ""

         ' Set the EditItemIndex property to -1 to exit editing mode. Be sure 
         ' to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = -1
         BindList()

      End Sub

      Sub Update_Command(sender As Object, e As DataListCommandEventArgs) 

         ' Retrieve the updated values from the selected item.
         Dim item As String = _
             (CType(e.Item.FindControl("ItemLabel"), Label)).Text
         Dim qty As String = _
             (CType(e.Item.FindControl("QtyTextBox"), TextBox)).Text
         Dim price As String = _
             (CType(e.Item.FindControl("PriceTextBox"), TextBox)).Text

         ' With a database, use an update command to update the data.
         ' Because the data source in this example is an in-memory 
         ' DataTable, delete the old row and replace it with a new one.

         ' Filter the CartView for the selected item and remove it from 
         ' the data source.
         CartView.RowFilter = "Item='" & item & "'"
         If CartView.Count > 0 Then 
       
            CartView.Delete(0)
         
         End If
         CartView.RowFilter = ""

         ' ***************************************************************
         ' Insert data validation code here. Make sure to validate the
         ' values entered by the user before converting to the appropriate
         ' data types and updating the data source.
         ' ***************************************************************

         ' Add a new entry to replace the previous item.
         Dim dr As DataRow = Cart.NewRow()
         dr(0) = qty
         dr(1) = item
         ' If necessary, remove the '$' character from the price before 
         ' converting the price to a Double.
         If price.Chars(0) = "$" Then

            dr(2) = Convert.ToDouble(price.Substring(1))

         Else

            dr(2) = Convert.ToDouble(price)
         
         End If

         Cart.Rows.Add(dr)

         ' Set the EditItemIndex property to -1 to exit editing mode. 
         ' Be sure to rebind the DataList to the data source to refresh 
         ' the control.
         ItemsList.EditItemIndex = -1
         BindList()

      End Sub

   </script>

</head>
<body>

   <form id="form1" runat="server">

      <h3>DataList Edit Example</h3>

      Click <b>Edit</b> to edit the values of the item.

      <br /><br />
       
      <asp:DataList id="ItemsList"
           GridLines="Both"
           RepeatColumns="3"
           RepeatDirection="Horizontal"
           CellPadding="3"
           CellSpacing="0"
           OnEditCommand="Edit_Command"
           OnUpdateCommand="Update_Command"
           OnDeleteCommand="Delete_Command"
           OnCancelCommand="Cancel_Command"
           runat="server">

         <HeaderStyle BackColor="#aaaadd">
         </HeaderStyle>

         <AlternatingItemStyle BackColor="Gainsboro">
         </AlternatingItemStyle>

         <EditItemStyle BackColor="yellow">
         </EditItemStyle>

         <HeaderTemplate>

            Items

         </HeaderTemplate>
         
         <ItemTemplate>

            Item:
            <%# DataBinder.Eval(Container.DataItem, "Item") %> 

            <br />

            Quantity:
            <%# DataBinder.Eval(Container.DataItem, "Qty") %>

            <br />

            Price:
            <%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>

            <br />

            <asp:LinkButton id="EditButton" 
                 Text="Edit" 
                 CommandName="Edit"
                 runat="server"/>

         </ItemTemplate>
              
         <EditItemTemplate>

            Item:
            <asp:Label id="ItemLabel" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Item") %>' 
                 runat="server"/>

            <br />

            Quantity:
            <asp:TextBox id="QtyTextBox" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Qty") %>' 
                 runat="server"/>

            <br />

            Price:
            <asp:TextBox id="PriceTextBox" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>' 
                 runat="server"/>

            <br />

            <asp:LinkButton id="UpdateButton" 
                 Text="Update" 
                 CommandName="Update" 
                 runat="server"/>

            <asp:LinkButton id="DeleteButton" 
                 Text="Delete" 
                 CommandName="Delete" 
                 runat="server"/>

            <asp:LinkButton id="CancelButton" 
                 Text="Cancel" 
                 CommandName="Cancel" 
                 runat="server"/>

         </EditItemTemplate>

      </asp:DataList>

   </form>

</body>
</html>

備註

CancelCommand按一下控制項中 DataList 專案的按鈕時, Cancel 就會引發 事件。

DeleteCommand按一下控制項中 DataList 專案的按鈕時, Delete 就會引發 事件。

EditCommand按一下控制項中 DataList 專案的按鈕時, Edit 就會引發 事件。

ItemCommand按一下控制項中 DataList 專案的任何按鈕時,就會引發 事件。 這可讓您以程式設計方式測試按一下特定命令按鈕的時間,並採取適當的動作。 此事件通常用來處理控制項的 DataList 自訂命令按鈕。

UpdateCommand按一下控制項中 DataList 專案的按鈕時, Update 就會引發 事件。

建立 DataListCommandEventHandler 委派時,必須識別處理事件的方法。 若要使事件與您的事件處理常式產生關聯,請將委派的執行個體 (Instance) 加入至事件。 除非您移除委派,否則每當事件發生時就會呼叫事件處理常式。 如需事件處理常式委派的詳細資訊,請參閱 處理和引發事件

擴充方法

GetMethodInfo(Delegate)

取得表示特定委派所代表之方法的物件。

適用於

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