EditCommandColumn 类
定义
重要
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DataGrid 控件的一种特殊列类型，包含用于编辑每行中的数据项的 Edit 按钮。
public ref class EditCommandColumn : System::Web::UI::WebControls::DataGridColumnpublic class EditCommandColumn : System.Web.UI.WebControls.DataGridColumntype EditCommandColumn = class
inherit DataGridColumnPublic Class EditCommandColumn
Inherits DataGridColumn- 继承
示例
下面的代码示例演示如何将 对象添加到EditCommandColumnDataGrid控件。
<%@ 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" >
<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>
注解
EditCommandColumn使用 类为DataGrid控件创建一个特殊列，其中包含Edit网格中每个数据行的 、 Update和 Cancel 按钮。 通过这些按钮，可以编辑控件中 DataGrid 某一行的值。
如果未选择任何行，则 控件中EditCommandColumn每个数据行的 对象中DataGrid都会显示一个Edit按钮。
Edit单击项的按钮时，EditCommand将引发 事件，并将该Edit按钮替换为 Update 和 Cancel 按钮。 需要提供代码来处理 EditCommand 事件。 典型的事件处理程序将 EditItemIndex 属性设置为所选行，然后将数据重新绑定到 控件 DataGrid 。
注意
必须为 、 EditText和 UpdateText 属性提供值CancelText。 否则，关联的按钮将不会显示在 中 EditCommandColumn。
可以通过设置 ButtonType 属性，将 中的EditCommandColumn按钮设置为显示为超链接或按钮。
Update单击 或 Cancel 按钮将分别引发 UpdateCommand 或 CancelCommand 事件。 需要提供代码来处理这些事件。
事件的典型处理程序 UpdateCommand 会更新数据，将 属性设置为 EditItemIndex-1 (以取消选择项) ，然后将数据重新绑定到控件 DataGrid 。
事件的典型处理程序 CancelCommand 将 属性设置为 EditItemIndex-1 (以取消选择项) ，然后将数据 DataGrid 重新绑定到 控件。
注意
对象 EditCommandColumn 可用于显示用户输入，其中可能包括恶意客户端脚本。 在应用程序中显示之前，请检查从客户端发送的任何信息，以获取可执行脚本、SQL 语句或其他代码。 在控件中 DataGrid 显示输入文本之前，可以使用验证控件来验证用户输入。 ASP.NET 提供输入请求验证功能，以阻止用户输入中的脚本和 HTML。 有关详细信息，请参阅 保护标准控件、 如何：通过对字符串应用 HTML 编码在 Web 应用程序中防止脚本攻击和 验证 ASP.NET 网页中的用户输入。
默认情况下，在单击控件中的EditCommandColumn按钮时Update执行页面验证。 页面验证确定与页面上的验证控件关联的输入控件是否都通过验证控件指定的验证规则。 若要防止发生页面验证，请将 CausesValidation 属性设置为 false。
构造函数
| EditCommandColumn() |
初始化 EditCommandColumn 类的新实例。 |
属性
方法
| Equals(Object) |
确定指定对象是否等于当前对象。 (继承自 Object) |
| GetHashCode() |
作为默认哈希函数。 (继承自 Object) |
| GetType() |
获取当前实例的 Type。 (继承自 Object) |
| Initialize() |
提供用于将派生自 DataGridColumn 类的列重置为其初始状态的基实现。 (继承自 DataGridColumn) |
| InitializeCell(TableCell, Int32, ListItemType) |
初始化列中的单元格。 |
| LoadViewState(Object) |
加载 DataGridColumn 对象的状态。 (继承自 DataGridColumn) |
| MemberwiseClone() |
创建当前 Object 的浅表副本。 (继承自 Object) |
| OnColumnChanged() |
调用 OnColumnsChanged() 方法。 (继承自 DataGridColumn) |
| SaveViewState() |
保存 DataGridColumn 对象的当前状态。 (继承自 DataGridColumn) |
| ToString() |
返回列的字符串表示形式。 (继承自 DataGridColumn) |
| TrackViewState() |
导致跟踪服务器控件的视图状态的更改，以便这些更改可以存储到服务器控件的 StateBag 对象中。 (继承自 DataGridColumn) |
显式接口实现
| IStateManager.IsTrackingViewState |
获取一个值，该值指示该列是否跟踪视图状态更改。 (继承自 DataGridColumn) |
| IStateManager.LoadViewState(Object) |
加载以前保存的状态。 (继承自 DataGridColumn) |
| IStateManager.SaveViewState() |
返回包含状态更改的对象。 (继承自 DataGridColumn) |
| IStateManager.TrackViewState() |
开始跟踪状态更改。 (继承自 DataGridColumn) |
