DataGridColumn.Visible Eigenschaft
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.
Ruft einen Wert ab, der angibt, ob die Spalte im DataGrid-Steuerelement sichtbar ist, oder legt diesen fest.
public:
property bool Visible { bool get(); void set(bool value); };public bool Visible { get; set; }member this.Visible : bool with get, setPublic Property Visible As BooleanEigenschaftswert
true, wenn die Spalte im DataGrid-Steuerelement sichtbar ist, andernfalls false. Der Standardwert ist true.
Beispiele
Im folgenden Codebeispiel wird veranschaulicht, wie die Visible Eigenschaft verwendet wird, um anzugeben, ob eine Spalte sichtbar 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 < 5; 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)
{
// Load sample data only once, when the page is first loaded.
if (!IsPostBack)
{
ItemsGrid.DataSource = CreateDataSource();
ItemsGrid.DataBind();
}
}
void Button_Click(Object sender, EventArgs e)
{
// Count the number of selected items in the DataGrid control.
int count = 0;
// Display the selected times.
Message.Text = "You Selected: <br />";
// Iterate through each item (row) in the DataGrid control and
// determine whether it is selected.
foreach (DataGridItem item in ItemsGrid.Items)
{
DetermineSelection(item, ref count);
}
// If no items are selected, display the appropriate message.
if (count == 0)
{
Message.Text = "No items selected";
}
}
void DetermineSelection(DataGridItem item, ref int count)
{
// Retrieve the SelectCheckBox CheckBox control from the
// specified item (row) in the DataGrid control.
CheckBox selection = (CheckBox)item.FindControl("SelectCheckBox");
// If the item is selected, display the appropriate message and
// increment the count of selected items.
if (selection != null)
{
if (selection.Checked)
{
Message.Text += "- " + item.Cells[1].Text + "<br />";
count++;
}
}
}
void Check_Change(Object sender, EventArgs e)
{
// Show or hide the first column depending on the value of
// the check box.
if (ShowCheckBox.Checked)
{
ItemsGrid.Columns[0].Visible = true;
}
else
{
ItemsGrid.Columns[0].Visible = false;
}
}
</script>
<head runat="server">
<title>DataGridColumn Visible Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGridColumn Visible Example</h3>
Select whether to show or hide the first column.
<br /><br />
<b>Product List</b>
<asp:DataGrid id="ItemsGrid"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
ShowFooter="True"
AutoGenerateColumns="False"
runat="server">
<HeaderStyle BackColor="#00aaaa">
</HeaderStyle>
<FooterStyle BackColor="#00aaaa">
</FooterStyle>
<Columns>
<asp:BoundColumn DataField="IntegerValue"
Visible="True"
HeaderText="Item"/>
<asp:BoundColumn DataField="StringValue"
Visible="True"
HeaderText="Description"/>
<asp:BoundColumn DataField="CurrencyValue"
Visible="True"
HeaderText="Price"
DataFormatString="{0:c}">
<ItemStyle HorizontalAlign="Right">
</ItemStyle>
</asp:BoundColumn>
<asp:TemplateColumn HeaderText="Select Item"
Visible="True" >
<ItemTemplate>
<asp:CheckBox id="SelectCheckBox"
Text="Add to Cart"
Checked="False"
runat="server"/>
</ItemTemplate>
</asp:TemplateColumn>
</Columns>
</asp:DataGrid>
<br /><br />
<asp:Button id="SubmitButton"
Text="Submit"
OnClick = "Button_Click"
runat="server"/>
<br /><br />
<asp:Label id="Message"
runat="server"/>
<hr />
<asp:CheckBox id="ShowCheckBox"
Text="Show first column"
AutoPostBack="True"
OnCheckedChanged="Check_Change"
Checked="True"
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 4
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)
' Load sample data only once, when the page is first loaded.
If Not IsPostBack Then
ItemsGrid.DataSource = CreateDataSource()
ItemsGrid.DataBind()
End If
End Sub
Sub Button_Click(sender As Object, e As EventArgs)
' Count the number of selected items in the DataGrid control.
Dim count As Integer = 0
' Display the selected times.
Message.Text = "You Selected: <br />"
' Iterate through each item (row) in the DataGrid control and
' determine whether it is selected.
Dim item As DataGridItem
For Each item In ItemsGrid.Items
DetermineSelection(item, count)
Next
' If no items are selected, display the appropriate message.
If count = 0 Then
Message.Text = "No items selected"
End If
End Sub
Sub DetermineSelection(item As DataGridItem, ByRef count As Integer)
' Retrieve the SelectCheckBox CheckBox control from the
' specified item (row) in the DataGrid control.
Dim selection As CheckBox = _
CType(item.FindControl("SelectCheckBox"), CheckBox)
' If the item is selected, display the appropriate message and
' increment the count of selected items.
If Not selection Is Nothing Then
If selection.Checked Then
Message.Text &= "- " & item.Cells(1).Text & "<br />"
count = count + 1
End If
End If
End Sub
Sub Check_Change(sender As Object, e As EventArgs)
' Show or hide the first column depending on the value of
' the check box.
If ShowCheckBox.Checked Then
ItemsGrid.Columns(0).Visible = True
Else
ItemsGrid.Columns(0).Visible = False
End If
End Sub
</script>
<head runat="server">
<title>DataGridColumn Visible Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGridColumn Visible Example</h3>
Select whether to show or hide the first column.
<br /><br />
<b>Product List</b>
<asp:DataGrid id="ItemsGrid"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
ShowFooter="True"
AutoGenerateColumns="False"
runat="server">
<HeaderStyle BackColor="#00aaaa">
</HeaderStyle>
<FooterStyle BackColor="#00aaaa">
</FooterStyle>
<Columns>
<asp:BoundColumn DataField="IntegerValue"
Visible="True"
HeaderText="Item"/>
<asp:BoundColumn DataField="StringValue"
Visible="True"
HeaderText="Description"/>
<asp:BoundColumn DataField="CurrencyValue"
Visible="True"
HeaderText="Price"
DataFormatString="{0:c}">
<ItemStyle HorizontalAlign="Right">
</ItemStyle>
</asp:BoundColumn>
<asp:TemplateColumn HeaderText="Select Item"
Visible="True" >
<ItemTemplate>
<asp:CheckBox id="SelectCheckBox"
Text="Add to Cart"
Checked="False"
runat="server"/>
</ItemTemplate>
</asp:TemplateColumn>
</Columns>
</asp:DataGrid>
<br /><br />
<asp:Button id="SubmitButton"
Text="Submit"
OnClick = "Button_Click"
runat="server"/>
<br /><br />
<asp:Label id="Message"
runat="server"/>
<hr />
<asp:CheckBox id="ShowCheckBox"
Text="Show first column"
AutoPostBack="True"
OnCheckedChanged="Check_Change"
Checked="True"
runat="server"/>
</form>
</body>
</html>
Hinweise
Verwenden Sie die Eigenschaft, um programmgesteuert zu steuern, ob die Visible Spalte im DataGrid Steuerelement sichtbar ist.