DataGridCommandEventArgs 类

定义

CancelCommand 控件的下列事件提供数据:DeleteCommandEditCommandItemCommandUpdateCommandDataGrid 事件。Provides data for the CancelCommand, DeleteCommand, EditCommand, ItemCommand, and UpdateCommand events of the DataGrid control. 此类不能被继承。This class cannot be inherited.

public ref class DataGridCommandEventArgs : System::Web::UI::WebControls::CommandEventArgs
public class DataGridCommandEventArgs : System.Web.UI.WebControls.CommandEventArgs
type DataGridCommandEventArgs = class
    inherit CommandEventArgs
Public Class DataGridCommandEventArgs
Inherits CommandEventArgs
继承
DataGridCommandEventArgs

示例

下面的代码示例演示EditCommand如何为、和UpdateCommand事件指定和编写事件处理CancelCommand程序, 以编辑DataGrid控件中的项。The following code example demonstrates how to specify and code event handlers for the EditCommand, CancelCommand, and UpdateCommand events to edit items in the DataGrid control.


<%@ 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" >
   <script runat="server">
 
      // The Cart and CartView objects temporarily store the data source
      // for the DataGrid 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 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 (!IsPostBack)
         {

            BindGrid();

         }
                   
      }
 
      void ItemsGrid_Edit(Object sender, DataGridCommandEventArgs e) 
      {

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

      }
 
      void ItemsGrid_Cancel(Object sender, DataGridCommandEventArgs e) 
      {

         // Set the EditItemIndex property to -1 to exit editing mode. 
         // Be sure to rebind the DateGrid to the data source to refresh
         // the control.
         ItemsGrid.EditItemIndex = -1;
         BindGrid();

      }
 
      void ItemsGrid_Update(Object sender, DataGridCommandEventArgs e) 
      {

         // Retrieve the text boxes that contain the values to update.
         // For bound columns, the edited value is stored in a TextBox.
         // The TextBox is the 0th control in a cell's Controls collection.
         // Each cell in the Cells collection of a DataGrid item represents
         // a column in the DataGrid control.
         TextBox qtyText = (TextBox)e.Item.Cells[3].Controls[0];
         TextBox priceText = (TextBox)e.Item.Cells[4].Controls[0];
 
         // Retrieve the updated values.
         String item = e.Item.Cells[2].Text;
         String qty = qtyText.Text;
         String price = priceText.Text;
        
         DataRow dr;
 
         // 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.
 
         // Remove the old entry and clear the row filter.
         CartView.RowFilter = "Item='" + item + "'";
         if (CartView.Count > 0)
         {
            CartView.Delete(0);
         }
         CartView.RowFilter = "";
 
         // ***************************************************************
         // Insert data validation code here. Be sure to validate the
         // values entered by the user before converting to the appropriate
         // data types and updating the data source.
         // ***************************************************************

         // Add the new entry.
         dr = Cart.NewRow();
         dr[0] = Convert.ToInt32(qty);
         dr[1] = item;

         // If necessary, remove the '$' character from the price before 
         // converting it to a Double.
         if(price[0] == '$')
         {
            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 DateGrid to the data source to refresh
         // the control.
         ItemsGrid.EditItemIndex = -1;
         BindGrid();

      }
 
      void BindGrid() 
      {

         // Set the data source and bind to the Data Grid control.
         ItemsGrid.DataSource = CartView;
         ItemsGrid.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 ItemsGrid_Command(Object sender, DataGridCommandEventArgs e)
      {

         switch(((LinkButton)e.CommandSource).CommandName)
         {

            case "Delete":
               DeleteItem(e);
               break;

            // Add other cases here, if there are multiple ButtonColumns in 
            // the DataGrid control.

            default:
               // Do nothing.
               break;

         }

      }

      void DeleteItem(DataGridCommandEventArgs e)
      {

         // e.Item is the table row where the command is raised. For bound
         // columns, the value is stored in the Text property of a TableCell.
         TableCell itemCell = e.Item.Cells[2];
         string item = itemCell.Text;

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

         // Rebind the data source to refresh the DataGrid control.
         BindGrid();

      }
 
   </script>
 
<head runat="server">
    <title>DataGrid Editing Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataGrid Editing Example</h3>
 
      <asp:DataGrid id="ItemsGrid"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           OnEditCommand="ItemsGrid_Edit"
           OnCancelCommand="ItemsGrid_Cancel"
           OnUpdateCommand="ItemsGrid_Update"
           OnItemCommand="ItemsGrid_Command"
           AutoGenerateColumns="false"
           runat="server">

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

            <asp:EditCommandColumn
                 EditText="Edit"
                 CancelText="Cancel"
                 UpdateText="Update" 
                 HeaderText="Edit item">

               <ItemStyle Wrap="False">
               </ItemStyle>

               <HeaderStyle Wrap="False">
               </HeaderStyle>

            </asp:EditCommandColumn>

            <asp:ButtonColumn 
                 HeaderText="Delete item" 
                 ButtonType="LinkButton" 
                 Text="Delete" 
                 CommandName="Delete"/>  
 
            <asp:BoundColumn HeaderText="Item" 
                 ReadOnly="True" 
                 DataField="Item"/>
 
            <asp:BoundColumn HeaderText="Quantity" 
                 DataField="Qty"/>
 
            <asp:BoundColumn HeaderText="Price"
                 DataField="Price"
                 DataFormatString="{0:c}"/>
 
         </Columns>
 
      </asp:DataGrid>

   </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" >
   <script runat="server">
 
      ' The Cart and CartView objects temporarily store the data source
      ' for the DataGrid control while the page is being processed.
      Dim Cart As DataTable = New DataTable()
      Dim CartView As DataView    
 
      Sub Page_Load(sender 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

            BindGrid()

         End If
                   
      End Sub
 
      Sub ItemsGrid_Edit(sender As Object, e As DataGridCommandEventArgs) 

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

      End Sub
 
      Sub ItemsGrid_Cancel(sender As Object, e As DataGridCommandEventArgs) 

         ' Set the EditItemIndex property to -1 to exit editing mode.
         ' Be sure to rebind the DateGrid to the data source to refresh
         ' the control.
         ItemsGrid.EditItemIndex = -1
         BindGrid()

      End Sub
 
      Sub ItemsGrid_Update(sender As Object, e As DataGridCommandEventArgs) 

         ' Retrieve the text boxes that contain the values to update.
         ' For bound columns, the edited value is stored in a TextBox.
         ' The TextBox is the 0th control in a cell's Controls collection.
         ' Each cell in the Cells collection of a DataGrid item represents
         ' a column in the DataGrid control.
         Dim qtyText As TextBox = CType(e.Item.Cells(3).Controls(0), TextBox)
         Dim priceText As TextBox = CType(e.Item.Cells(4).Controls(0), TextBox)
 
         ' Retrieve the updated values.
         Dim item As String = e.Item.Cells(2).Text
         Dim qty As String = qtyText.Text
         Dim price As String = priceText.Text
        
         Dim dr As DataRow
 
         ' 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.
 
         ' Remove the old entry and clear the row filter.
         CartView.RowFilter = "Item='" & item & "'"
         If CartView.Count > 0 Then
       
            CartView.Delete(0)
         
         End If 
         CartView.RowFilter = ""
 
         ' ***************************************************************
         ' Insert data validation code here. Be sure to validate the
         ' values entered by the user before converting to the appropriate
         ' data types and updating the data source.
         ' ***************************************************************

         ' Add the new entry.
         dr = Cart.NewRow()
         dr(0) = Convert.ToInt32(qty)
         dr(1) = item

         ' If necessary, remove the '$' character from the price before 
         ' converting it to a Double.
         If price.Chars(0) = "$" 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 DateGrid to the data source to refresh
         ' the control.
         ItemsGrid.EditItemIndex = -1
         BindGrid()

      End Sub
 
      Sub BindGrid() 

         ' Set the data source and bind to the Data Grid control.
         ItemsGrid.DataSource = CartView
         ItemsGrid.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 ItemsGrid_Command(sender As Object, e As DataGridCommandEventArgs)

         Select (CType(e.CommandSource, LinkButton)).CommandName

            Case "Delete"
               DeleteItem(e)

            ' Add other cases here, if there are multiple ButtonColumns in 
            ' the DataGrid control.

            Case Else
               ' Do nothing.

         End Select

      End Sub

      Sub DeleteItem(e As DataGridCommandEventArgs)

         ' e.Item is the table row where the command is raised. For bound 
         ' columns, the value is stored in the Text property of a TableCell.
         Dim itemCell As TableCell = e.Item.Cells(2)
         Dim item As String = itemCell.Text

         ' Remove the selected item from the data source.         
         CartView.RowFilter = "Item='" & item + "'"
         If CartView.Count > 0 Then 
              
            CartView.Delete(0)

         End If
         
         CartView.RowFilter = ""

         ' Rebind the data source to refresh the DataGrid control.
         BindGrid()

      End Sub
 
   </script>
 
<head runat="server">
    <title>DataGrid Editing Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataGrid Editing Example</h3>
 
      <asp:DataGrid id="ItemsGrid"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           OnEditCommand="ItemsGrid_Edit"
           OnCancelCommand="ItemsGrid_Cancel"
           OnUpdateCommand="ItemsGrid_Update"
           OnItemCommand="ItemsGrid_Command"
           AutoGenerateColumns="false"
           runat="server">

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

            <asp:EditCommandColumn
                 EditText="Edit"
                 CancelText="Cancel"
                 UpdateText="Update" 
                 HeaderText="Edit item">

               <ItemStyle Wrap="False">
               </ItemStyle>

               <HeaderStyle Wrap="False">
               </HeaderStyle>

            </asp:EditCommandColumn>

            <asp:ButtonColumn 
                 HeaderText="Delete item" 
                 ButtonType="LinkButton" 
                 Text="Delete" 
                 CommandName="Delete"/>  
 
            <asp:BoundColumn HeaderText="Item" 
                 ReadOnly="True" 
                 DataField="Item"/>
 
            <asp:BoundColumn HeaderText="Quantity" 
                 DataField="Qty"/>
 
            <asp:BoundColumn HeaderText="Price"
                 DataField="Price"
                 DataFormatString="{0:c}"/>
 
         </Columns>
 
      </asp:DataGrid>

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


<%@ 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" >
   <script runat="server">
 
      // The Cart and CartView objects temporarily store the data source
      // for the DataGrid 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 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 (!IsPostBack)
         {

            BindGrid();

         }

         // Manually register the event-handling methods.
         ItemsGrid.EditCommand += 
             new DataGridCommandEventHandler(this.ItemsGrid_Edit);
         ItemsGrid.CancelCommand +=  
             new DataGridCommandEventHandler(this.ItemsGrid_Cancel);
         ItemsGrid.UpdateCommand += 
             new DataGridCommandEventHandler(this.ItemsGrid_Update);
         ItemsGrid.ItemCommand += 
             new DataGridCommandEventHandler(this.ItemsGrid_Command);
                   
      }
 
      void ItemsGrid_Edit(Object sender, DataGridCommandEventArgs e) 
      {

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

      }
 
      void ItemsGrid_Cancel(Object sender, DataGridCommandEventArgs e) 
      {

         // Set the EditItemIndex property to -1 to exit editing mode. 
         // Be sure to rebind the DateGrid to the data source to refresh
         // the control.
         ItemsGrid.EditItemIndex = -1;
         BindGrid();

      }
 
      void ItemsGrid_Update(Object sender, DataGridCommandEventArgs e) 
      {

         // Retrieve the text boxes that contain the values to update.
         // For bound columns, the edited value is stored in a TextBox.
         // The TextBox is the 0th control in a cell's Controls collection.
         // Each cell in the Cells collection of a DataGrid item represents
         // a column in the DataGrid control.
         TextBox qtyText = (TextBox)e.Item.Cells[3].Controls[0];
         TextBox priceText = (TextBox)e.Item.Cells[4].Controls[0];
 
         // Retrieve the updated values.
         String item = e.Item.Cells[2].Text;
         String qty = qtyText.Text;
         String price = priceText.Text;
        
         DataRow dr;
 
         // 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.
 
         // Remove the old entry and clear the row filter.
         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 the new entry.
         dr = Cart.NewRow();
         dr[0] = Convert.ToInt32(qty);
         dr[1] = item;

         // If necessary, remove the '$' character, from the price before
         // converting it to a Double.
         if(price[0] == '$')
         {
            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 DateGrid to the data source to refresh
         // the control.
         ItemsGrid.EditItemIndex = -1;
         BindGrid();

      }
 
      void BindGrid() 
      {

         // Set the data source and bind to the Data Grid control.
         ItemsGrid.DataSource = CartView;
         ItemsGrid.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 ItemsGrid_Command(Object sender, DataGridCommandEventArgs e)
      {

         switch(((LinkButton)e.CommandSource).CommandName)
         {

            case "Delete":
               DeleteItem(e);
               break;

            // Add other cases here, if there are multiple ButtonColumns in 
            // the DataGrid control.

            default:
               // Do nothing.
               break;

         }

      }

      void DeleteItem(DataGridCommandEventArgs e)
      {

         // e.Item is the table row where the command is raised. For bound
         // columns, the value is stored in the Text property of a TableCell.
         TableCell itemCell = e.Item.Cells[2];
         string item = itemCell.Text;

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

         // Rebind the data source to refresh the DataGrid control.
         BindGrid();

      }
 
   </script>
 
<head runat="server">
    <title>DataGrid Editing Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataGrid Editing Example</h3>
 
      <asp:DataGrid id="ItemsGrid"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           OnEditCommand="ItemsGrid_Edit"
           OnCancelCommand="ItemsGrid_Cancel"
           OnUpdateCommand="ItemsGrid_Update"
           OnItemCommand="ItemsGrid_Command"
           AutoGenerateColumns="false"
           runat="server">

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

            <asp:EditCommandColumn
                 EditText="Edit"
                 CancelText="Cancel"
                 UpdateText="Update" 
                 HeaderText="Edit item">

               <ItemStyle Wrap="False">
               </ItemStyle>

               <HeaderStyle Wrap="False">
               </HeaderStyle>

            </asp:EditCommandColumn>

            <asp:ButtonColumn 
                 HeaderText="Delete item" 
                 ButtonType="LinkButton" 
                 Text="Delete" 
                 CommandName="Delete"/>  
 
            <asp:BoundColumn HeaderText="Item" 
                 ReadOnly="True" 
                 DataField="Item"/>
 
            <asp:BoundColumn HeaderText="Quantity" 
                 DataField="Qty"/>
 
            <asp:BoundColumn HeaderText="Price"
                 DataField="Price"
                 DataFormatString="{0:c}"/>
 
         </Columns>
 
      </asp:DataGrid>

   </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" >
   <script runat="server">
 
      ' The Cart and CartView objects temporarily store the data source
      ' for the DataGrid control while the page is being processed.
      Dim Cart As DataTable = New DataTable()
      Dim CartView As DataView    
 
      Sub Page_Load(sender 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

            BindGrid()

         End If

         ' Manually register the event-handling methods.
         AddHandler ItemsGrid.EditCommand, AddressOf ItemsGrid_Edit
         AddHandler ItemsGrid.CancelCommand, AddressOf ItemsGrid_Cancel
         AddHandler ItemsGrid.UpdateCommand, AddressOf ItemsGrid_Update
         AddHandler ItemsGrid.ItemCommand, AddressOf ItemsGrid_Command
                   
      End Sub
 
      Sub ItemsGrid_Edit(sender As Object, e As DataGridCommandEventArgs) 

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

      End Sub
 
      Sub ItemsGrid_Cancel(sender As Object, e As DataGridCommandEventArgs) 

         ' Set the EditItemIndex property to -1 to exit editing mode. 
         ' Be sure to rebind the DateGrid to the data source to refresh
         ' the control.
         ItemsGrid.EditItemIndex = -1
         BindGrid()

      End Sub
 
      Sub ItemsGrid_Update(sender As Object, e As DataGridCommandEventArgs) 

         ' Retrieve the text boxes that contain the values to update.
         ' For bound columns, the edited value is stored in a TextBox.
         ' The TextBox is the 0th control in a cell's Controls collection.
         ' Each cell in the Cells collection of a DataGrid item represents
         ' a column in the DataGrid control.
         Dim qtyText As TextBox = CType(e.Item.Cells(3).Controls(0), TextBox)
         Dim priceText As TextBox = CType(e.Item.Cells(4).Controls(0), TextBox)
 
         ' Retrieve the updated values.
         Dim item As String = e.Item.Cells(2).Text
         Dim qty As String = qtyText.Text
         Dim price As String = priceText.Text
        
         Dim dr As DataRow
 
         ' 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.
 
         ' Remove the old entry and clear the row filter.
         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 the new entry.
         dr = Cart.NewRow()
         dr(0) = Convert.ToInt32(qty)
         dr(1) = item

         ' If necessary, remove the '$' character, from the price before 
         ' converting it to a Double.
         If price.Chars(0) = "$" 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 DateGrid to the data source to refresh
         ' the control.
         ItemsGrid.EditItemIndex = -1
         BindGrid()

      End Sub
 
      Sub BindGrid() 

         ' Set the data source and bind to the Data Grid control.
         ItemsGrid.DataSource = CartView
         ItemsGrid.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 ItemsGrid_Command(sender As Object, e As DataGridCommandEventArgs)

         Select (CType(e.CommandSource, LinkButton)).CommandName

            Case "Delete"
               DeleteItem(e)

            ' Add other cases here, if there are multiple ButtonColumns in 
            ' the DataGrid control.

            Case Else
               ' Do nothing.

         End Select

      End Sub

      Sub DeleteItem(e As DataGridCommandEventArgs)

         ' e.Item is the table row where the command is raised. For bound
         ' columns, the value is stored in the Text property of a TableCell.
         Dim itemCell As TableCell = e.Item.Cells(2)
         Dim item As String = itemCell.Text

         ' Remove the selected item from the data source.         
         CartView.RowFilter = "Item='" & item + "'"
         If CartView.Count > 0 Then 
              
            CartView.Delete(0)

         End If
         
         CartView.RowFilter = ""

         ' Rebind the data source to refresh the DataGrid control.
         BindGrid()

      End Sub
 
   </script>
 
<head runat="server">
    <title>DataGrid Editing Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataGrid Editing Example</h3>
 
      <asp:DataGrid id="ItemsGrid"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           AutoGenerateColumns="false"
           runat="server">

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

            <asp:EditCommandColumn
                 EditText="Edit"
                 CancelText="Cancel"
                 UpdateText="Update" 
                 HeaderText="Edit item">

               <ItemStyle Wrap="False">
               </ItemStyle>

               <HeaderStyle Wrap="False">
               </HeaderStyle>

            </asp:EditCommandColumn>

            <asp:ButtonColumn 
                 HeaderText="Delete item" 
                 ButtonType="LinkButton" 
                 Text="Delete" 
                 CommandName="Delete"/>  
 
            <asp:BoundColumn HeaderText="Item" 
                 ReadOnly="True" 
                 DataField="Item"/>
 
            <asp:BoundColumn HeaderText="Quantity" 
                 DataField="Qty"/>
 
            <asp:BoundColumn HeaderText="Price"
                 DataField="Price"
                 DataFormatString="{0:c}"/>
 
         </Columns>
 
      </asp:DataGrid>

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

注解

单击CancelCommand 控件DataGrid中某项的 "取消" 按钮时, 将引发该事件。The CancelCommand event is raised when the Cancel button for an item in the DataGrid control is clicked.

单击DeleteCommand 控件DataGrid中某项的 "删除" 按钮时, 将引发该事件。The DeleteCommand event is raised when the Delete button for an item in the DataGrid control is clicked.

单击EditCommand 控件DataGrid中某项的 "编辑" 按钮时, 将引发该事件。The EditCommand event is raised when the Edit button for an item in the DataGrid control is clicked.

单击ItemCommand 控件DataGrid中某一项的任何按钮时, 将引发该事件。The ItemCommand event is raised when any button for an item in the DataGrid control is clicked. 这允许你以编程方式测试单击特定命令按钮的时间并采取适当的操作。This allows you to programmatically test for when a specific command button is clicked and take appropriate action. 此事件通常用于处理DataGrid控件的自定义命令按钮。This event is commonly used to handle custom command buttons for the DataGrid control.

单击UpdateCommand 控件DataGrid中某项的 "更新" 按钮时, 将引发该事件。The UpdateCommand event is raised when the Update button for an item in the DataGrid control is clicked.

有关实例DataGridCommandEventArgs的初始属性值的列表, DataGridCommandEventArgs请参见构造函数。For a list of initial property values for an instance of DataGridCommandEventArgs, see the DataGridCommandEventArgs constructor.

有关处理事件的详细信息, 请参阅处理和引发事件For more information about handling events, see Handling and Raising Events.

构造函数

DataGridCommandEventArgs(DataGridItem, Object, CommandEventArgs)

初始化 DataGridCommandEventArgs 类的新实例。Initializes a new instance of the DataGridCommandEventArgs class.

属性

CommandArgument

获取命令的参数。Gets the argument for the command.

(继承自 CommandEventArgs)
CommandName

获取命令的名称。Gets the name of the command.

(继承自 CommandEventArgs)
CommandSource

获取命令源。Gets the source of the command.

Item

获取 DataGrid 控件中包含命令源的项。Gets the item containing the command source in the DataGrid control.

方法

Equals(Object)

确定指定对象是否等于当前对象。Determines whether the specified object is equal to the current object.

(继承自 Object)
GetHashCode()

用作默认哈希函数。Serves as the default hash function.

(继承自 Object)
GetType()

获取当前实例的 TypeGets the Type of the current instance.

(继承自 Object)
MemberwiseClone()

创建当前 Object 的浅表副本。Creates a shallow copy of the current Object.

(继承自 Object)
ToString()

返回表示当前对象的字符串。Returns a string that represents the current object.

(继承自 Object)

适用于

另请参阅