DataGridColumnCollection.Add(DataGridColumn) Methode
Definition
Wichtig
Einige Informationen beziehen sich auf Vorabversionen, die vor dem Release ggf. grundlegend überarbeitet werden. Microsoft übernimmt hinsichtlich der hier bereitgestellten Informationen keine Gewährleistungen, seien sie ausdrücklich oder konkludent.
Fügt das angegebene, von DataGridColumn abgeleitete Spaltenobjekt an das Ende der DataGridColumnCollection-Auflistung an.
public:
void Add(System::Web::UI::WebControls::DataGridColumn ^ column);public void Add (System.Web.UI.WebControls.DataGridColumn column);member this.Add : System.Web.UI.WebControls.DataGridColumn -> unitPublic Sub Add (column As DataGridColumn)Parameter
- column
- DataGridColumn
Das von DataGridColumn abgeleitete Spaltenobjekt, das an DataGridColumnCollection angefügt werden soll.
Beispiele
Im folgenden Codebeispiel wird veranschaulicht, wie Die Add Methode zum dynamischen Hinzufügen einer Spalte zum DataGrid Steuerelement verwendet wird. Beachten Sie, dass die Columns Eigenschaft des DataGrid Steuerelements eine Instanz der DataGridColumnCollection Klasse ist.
<%@ 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">
ICollection CreateDataSource()
{
// Create sample data for the DataGrid control.
DataTable dt = new DataTable();
DataRow dr;
// Define the columns of the table.
dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
dt.Columns.Add(new DataColumn("StringValue", typeof(string)));
dt.Columns.Add(new DataColumn("CurrencyValue", typeof(double)));
// Populate the table with sample values.
for (int i = 0; i < 9; i++)
{
dr = dt.NewRow();
dr[0] = i;
dr[1] = "Item " + i.ToString();
dr[2] = 1.23 * (i + 1);
dt.Rows.Add(dr);
}
DataView dv = new DataView(dt);
return dv;
}
void Page_Load(Object sender, EventArgs e)
{
// Create a DataGrid control.
DataGrid ItemsGrid = new DataGrid();
// Set the properties of the DataGrid.
ItemsGrid.ID = "ItemsGrid";
ItemsGrid.BorderColor = System.Drawing.Color.Black;
ItemsGrid.CellPadding = 3;
ItemsGrid.AutoGenerateColumns = false;
// Set the styles for the DataGrid.
ItemsGrid.HeaderStyle.BackColor =
System.Drawing.Color.FromArgb(0x0000aaaa);
// Create the columns for the DataGrid control. The DataGrid
// columns are dynamically generated. Therefore, the columns
// must be re-created each time the page is refreshed.
// Create and add the columns to the collection.
ItemsGrid.Columns.Add(CreateBoundColumn("IntegerValue", "Item"));
ItemsGrid.Columns.Add(
CreateBoundColumn("StringValue", "Description"));
ItemsGrid.Columns.Add(
CreateBoundColumn("CurrencyValue", "Price", "{0:c}",
HorizontalAlign.Right));
ItemsGrid.Columns.Add(
CreateLinkColumn("http://www.microsoft.com", "_self",
"Microsoft", "Related link"));
// Specify the data source and bind it to the control.
ItemsGrid.DataSource = CreateDataSource();
ItemsGrid.DataBind();
// Add the DataGrid control to the Controls collection of
// the PlaceHolder control.
Place.Controls.Add(ItemsGrid);
}
BoundColumn CreateBoundColumn(String DataFieldValue,
String HeaderTextValue)
{
// This version of the CreateBoundColumn method sets only the
// DataField and HeaderText properties.
// Create a BoundColumn.
BoundColumn column = new BoundColumn();
// Set the properties of the BoundColumn.
column.DataField = DataFieldValue;
column.HeaderText = HeaderTextValue;
return column;
}
BoundColumn CreateBoundColumn(String DataFieldValue,
String HeaderTextValue, String FormatValue,
HorizontalAlign AlignValue)
{
// This version of CreateBoundColumn method sets the DataField,
// HeaderText, and DataFormatString properties. It also sets the
// HorizontalAlign property of the ItemStyle property of the column.
// Create a BoundColumn using the overloaded CreateBoundColumn method.
BoundColumn column = CreateBoundColumn(DataFieldValue, HeaderTextValue);
// Set the properties of the BoundColumn.
column.DataFormatString = FormatValue;
column.ItemStyle.HorizontalAlign = AlignValue;
return column;
}
HyperLinkColumn CreateLinkColumn(String NavUrlValue,
String TargetValue, String TextValue, String HeaderTextValue)
{
// Create a BoundColumn.
HyperLinkColumn column = new HyperLinkColumn();
// Set the properties of the ButtonColumn.
column.NavigateUrl = NavUrlValue;
column.Target = TargetValue;
column.Text = TextValue;
column.HeaderText = HeaderTextValue;
return column;
}
</script>
<head runat="server">
<title>DataGrid Constructor Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGrid Constructor Example</h3>
<b>Product List</b>
<asp:PlaceHolder id="Place"
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 runat="server">
Function CreateDataSource() As ICollection
' Create sample data for the DataGrid control.
Dim dt As DataTable = New DataTable()
Dim dr As DataRow
' Define the columns of the table.
dt.Columns.Add(New DataColumn("IntegerValue", GetType(Int32)))
dt.Columns.Add(New DataColumn("StringValue", GetType(string)))
dt.Columns.Add(New DataColumn("CurrencyValue", GetType(double)))
' Populate the table with sample values.
Dim i As Integer
For i = 0 to 8
dr = dt.NewRow()
dr(0) = i
dr(1) = "Item " & i.ToString()
dr(2) = 1.23 * (i + 1)
dt.Rows.Add(dr)
Next i
Dim dv As DataView = New DataView(dt)
Return dv
End Function
Sub Page_Load(sender As Object, e As EventArgs)
' Create a DataGrid control.
Dim ItemsGrid As DataGrid = New DataGrid()
' Set the properties of the DataGrid.
ItemsGrid.ID = "ItemsGrid"
ItemsGrid.BorderColor = System.Drawing.Color.Black
ItemsGrid.CellPadding = 3
ItemsGrid.AutoGenerateColumns = False
' Set the styles for the DataGrid.
ItemsGrid.HeaderStyle.BackColor = System.Drawing.Color.FromArgb(&H0000aaaa)
' Create the columns for the DataGrid control. The DataGrid
' columns are dynamically generated. Therefore, the columns
' must be re-created each time the page is refreshed.
' Create and add the columns to the collection.
ItemsGrid.Columns.Add(CreateBoundColumn("IntegerValue", "Item"))
ItemsGrid.Columns.Add( _
CreateBoundColumn("StringValue", "Description"))
ItemsGrid.Columns.Add( _
CreateBoundColumn("CurrencyValue", "Price", "{0:c}", _
HorizontalAlign.Right))
ItemsGrid.Columns.Add( _
CreateLinkColumn("http:'www.microsoft.com", "_self", _
"Microsoft", "Related link"))
' Specify the data source and bind it to the control.
ItemsGrid.DataSource = CreateDataSource()
ItemsGrid.DataBind()
' Add the DataGrid control to the Controls collection of
' the PlaceHolder control.
Place.Controls.Add(ItemsGrid)
End Sub
Function CreateBoundColumn(DataFieldValue As String, HeaderTextValue As String) As BoundColumn
' This version of CreateBoundColumn method sets only the
' DataField and HeaderText properties.
' Create a BoundColumn.
Dim column As BoundColumn = New BoundColumn()
' Set the properties of the BoundColumn.
column.DataField = DataFieldValue
column.HeaderText = HeaderTextValue
Return column
End Function
Function CreateBoundColumn(DataFieldValue As String, _
HeaderTextValue As String, FormatValue As String, _
AlignValue As HorizontalAlign) As BoundColumn
' This version of CreateBoundColumn method sets the DataField,
' HeaderText, and DataFormatString properties. It also sets the
' HorizontalAlign property of the ItemStyle property of the column.
' Create a BoundColumn using the overloaded CreateBoundColumn method.
Dim column As BoundColumn = CreateBoundColumn(DataFieldValue, HeaderTextValue)
' Set the properties of the BoundColumn.
column.DataFormatString = FormatValue
column.ItemStyle.HorizontalAlign = AlignValue
Return column
End Function
Function CreateLinkColumn(NavUrlValue As String, TargetValue As String, _
TextValue As String, HeaderTextValue As String) As HyperLinkColumn
' Create a BoundColumn.
Dim column As HyperLinkColumn = New HyperLinkColumn()
' Set the properties of the ButtonColumn.
column.NavigateUrl = NavUrlValue
column.Target = TargetValue
column.Text = TextValue
column.HeaderText = HeaderTextValue
Return column
End Function
</script>
<head runat="server">
<title>DataGrid Constructor Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGrid Constructor Example</h3>
<b>Product List</b>
<asp:PlaceHolder id="Place"
runat="server"/>
</form>
</body>
</html>
Hinweise
Verwenden Sie diese Methode, um ein DataGridColumnabgeleitetes Spaltenobjekt zum Ende einer DataGridColumnCollection Auflistung hinzuzufügen.
Das DataGrid Steuerelement speichert den Inhalt seiner Columns Auflistung nicht im Ansichtszustand. Wenn Sie eine Spalte dynamisch hinzufügen oder entfernen möchten, müssen Sie die Spalte programmgesteuert hinzufügen oder entfernen, wenn die Seite aktualisiert wird. Stellen Sie eine Page_Init Funktion bereit, die die Spalte hinzufügt oder entfernt, bevor das DataGrid Steuerelement den Zustand neu laden und selbst neu erstellen kann. Andernfalls werden die Änderungen an der Columns Auflistung beim Anzeigen des DataGrid Steuerelements nicht angezeigt.
Hinweis
Obwohl Sie Spalten programmgesteuert hinzufügen oder aus der Columns Auflistung des DataGrid Steuerelements entfernen können, ist es einfacher, die Spalten statisch auflisten und dann die Visible Eigenschaft zum Anzeigen oder Ausblenden jeder Spalte verwenden.