DataGridColumnCollection.Item[Int32] Eigenschaft
Definition
Wichtig
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Ruft ein von DataGridColumn abgeleitetes Spaltenobjekt am angegebenen Index aus der DataGridColumnCollection-Auflistung ab.
public:
property System::Web::UI::WebControls::DataGridColumn ^ default[int] { System::Web::UI::WebControls::DataGridColumn ^ get(int index); };[System.ComponentModel.Browsable(false)]
public System.Web.UI.WebControls.DataGridColumn this[int index] { get; }[<System.ComponentModel.Browsable(false)>]
member this.Item(int) : System.Web.UI.WebControls.DataGridColumnDefault Public ReadOnly Property Item(index As Integer) As DataGridColumnParameter
- index
- Int32
Der Index der abzurufenden, von DataGridColumn abgeleiteten Spalte in DataGridColumnCollection.
Eigenschaftswert
Eine von DataGridColumn abgeleitete Spalte am angegebenen Index in DataGridColumnCollection.
- Attribute
Beispiele
Im folgenden Codebeispiel wird veranschaulicht, wie Sie mithilfe des Indexers ein abgeleitetes DataGridColumnSpaltenobjekt aus der DataGridColumnCollection Auflistung abrufen. Der Überschriftentext aus dem DataGridColumnabgeleiteten Spaltenobjekt wird dann auf der Webseite für jedes Element in der Auflistung angezeigt.
<%@ 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 language="C#" runat="server">
DataTable Cart = new DataTable();
DataView CartView;
void Page_Load(Object sender, EventArgs e)
{
DataRow dr;
if (Session["ShoppingCart"] == null)
{
Cart.Columns.Add(new DataColumn("Qty", typeof(String)));
Cart.Columns.Add(new DataColumn("Item", typeof(String)));
Cart.Columns.Add(new DataColumn("Price", typeof(String)));
Session["ShoppingCart"] = Cart;
// Create sample data.
for (int i = 1; i <= 4; 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)).ToString();
Cart.Rows.Add(dr);
}
}
else
Cart = (DataTable)Session["ShoppingCart"];
CartView = new DataView(Cart);
CartView.Sort="Item";
if (!IsPostBack)
BindGrid();
}
void MyDataGrid_Edit(Object sender, DataGridCommandEventArgs e)
{
MyDataGrid.EditItemIndex = e.Item.ItemIndex;
BindGrid();
}
void MyDataGrid_Cancel(Object sender, DataGridCommandEventArgs e)
{
MyDataGrid.EditItemIndex = -1;
BindGrid();
}
void MyDataGrid_Update(Object sender, DataGridCommandEventArgs e)
{
// For bound columns, the edited value is stored in a TextBox.
// The TextBox is the 0th element in the column's cell.
TextBox qtyText = (TextBox)e.Item.Cells[2].Controls[0];
TextBox priceText = (TextBox)e.Item.Cells[3].Controls[0];
String item = e.Item.Cells[1].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 old entry.
CartView.RowFilter = "Item='" + item + "'";
if (CartView.Count > 0)
CartView.Delete(0);
CartView.RowFilter = "";
// Add new entry.
dr = Cart.NewRow();
dr[0] = qty;
dr[1] = item;
dr[2] = price;
Cart.Rows.Add(dr);
MyDataGrid.EditItemIndex = -1;
BindGrid();
}
void Button_Click(Object sender, EventArgs e)
{
Label1.Text = "Header Text for each column: <br />";
for (int i = 0; i < MyDataGrid.Columns.Count; i++)
{
Label1.Text += "<br />" + MyDataGrid.Columns[i].HeaderText;
}
}
void BindGrid()
{
MyDataGrid.DataSource = CartView;
MyDataGrid.DataBind();
}
</script>
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body style="font: 10pt verdana">
<form id="form1" runat="server">
<asp:DataGrid id="MyDataGrid" runat="server"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
Font-Names="Verdana"
Font-Size="8pt"
HeaderStyle-BackColor="#aaaadd"
OnEditCommand="MyDataGrid_Edit"
OnCancelCommand="MyDataGrid_Cancel"
OnUpdateCommand="MyDataGrid_Update"
AutoGenerateColumns="false">
<Columns>
<asp:EditCommandColumn
EditText="Edit"
CancelText="Cancel"
UpdateText="Update"
ItemStyle-Wrap="false"
HeaderText="Edit Command Column"
HeaderStyle-Wrap="false"/>
<asp:BoundColumn HeaderText="Item"
ReadOnly="true"
DataField="Item"/>
<asp:BoundColumn HeaderText="Quantity"
DataField="Qty"/>
<asp:BoundColumn HeaderText="Price"
DataField="Price"/>
</Columns>
</asp:DataGrid>
<br /><br />
<asp:Button id="Button1"
Text="Display Header Text for Columns"
OnClick="Button_Click"
runat="server"/>
<br /><br />
<asp:Label id="Label1"
runat="server"/>
</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 language="VB" runat="server">
Dim Cart As New DataTable()
Dim CartView As DataView
Sub Page_Load(sender As Object, e As EventArgs)
Dim dr As DataRow
If Session("ShoppingCart") Is Nothing Then
Cart.Columns.Add(New DataColumn("Qty", GetType(String)))
Cart.Columns.Add(New DataColumn("Item", GetType(String)))
Cart.Columns.Add(New DataColumn("Price", GetType(String)))
Session("ShoppingCart") = Cart
' Create sample data.
Dim i As Integer
For i = 1 To 4
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)).ToString()
Cart.Rows.Add(dr)
Next i
Else
Cart = CType(Session("ShoppingCart"), DataTable)
End If
CartView = New DataView(Cart)
CartView.Sort = "Item"
If Not IsPostBack Then
BindGrid()
End If
End Sub 'Page_Load
Sub MyDataGrid_Edit(sender As Object, e As DataGridCommandEventArgs)
MyDataGrid.EditItemIndex = e.Item.ItemIndex
BindGrid()
End Sub 'MyDataGrid_Edit
Sub MyDataGrid_Cancel(sender As Object, e As DataGridCommandEventArgs)
MyDataGrid.EditItemIndex = - 1
BindGrid()
End Sub 'MyDataGrid_Cancel
Sub MyDataGrid_Update(sender As Object, e As DataGridCommandEventArgs)
' For bound columns, the edited value is stored in a TextBox.
' The TextBox is the 0th element in the column's cell.
Dim qtyText As TextBox = CType(e.Item.Cells(2).Controls(0), TextBox)
Dim priceText As TextBox = CType(e.Item.Cells(3).Controls(0), TextBox)
Dim item As String = e.Item.Cells(1).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 old entry.
CartView.RowFilter = "Item='" & item & "'"
If CartView.Count > 0 Then
CartView.Delete(0)
End If
CartView.RowFilter = ""
' Add new entry.
dr = Cart.NewRow()
dr(0) = qty
dr(1) = item
dr(2) = price
Cart.Rows.Add(dr)
MyDataGrid.EditItemIndex = - 1
BindGrid()
End Sub 'MyDataGrid_Update
Sub Button_Click(sender As Object, e As EventArgs)
Label1.Text = "Header Text for each column: <br /><br />"
Dim i As Integer
For i = 0 To MyDataGrid.Columns.Count - 1
Label1.Text &= "<br />" & MyDataGrid.Columns(i).HeaderText
Next i
End Sub 'Button_Click
Sub BindGrid()
MyDataGrid.DataSource = CartView
MyDataGrid.DataBind()
End Sub 'BindGrid
</script>
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body style="font: 10pt verdana">
<form id="form1" runat="server">
<asp:DataGrid id="MyDataGrid" runat="server"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
Font-Names="Verdana"
Font-Size="8pt"
HeaderStyle-BackColor="#aaaadd"
OnEditCommand="MyDataGrid_Edit"
OnCancelCommand="MyDataGrid_Cancel"
OnUpdateCommand="MyDataGrid_Update"
AutoGenerateColumns="false">
<Columns>
<asp:EditCommandColumn
EditText="Edit"
CancelText="Cancel"
UpdateText="Update"
ItemStyle-Wrap="false"
HeaderText="Edit Command Column"
HeaderStyle-Wrap="false"/>
<asp:BoundColumn HeaderText="Item"
ReadOnly="true"
DataField="Item"/>
<asp:BoundColumn HeaderText="Quantity"
DataField="Qty"/>
<asp:BoundColumn HeaderText="Price"
DataField="Price"/>
</Columns>
</asp:DataGrid>
<br /><br />
<asp:Button id="Button1"
Text="Display Header Text for Columns"
OnClick="Button_Click"
runat="server"/>
<br /><br />
<asp:Label id="Label1"
runat="server"/>
</form>
</body>
</html>
Hinweise
Verwenden Sie diesen Indexer, um ein DataGridColumnabgeleitetes Spaltenobjekt aus der DataGridColumnCollection Auflistung am angegebenen Index mithilfe der Arraynotation abzurufen.