Style.BackColor-Eigenschaft
Ruft die Hintergrundfarbe des Webserversteuerelements ab oder legt diese fest.
Namespace: System.Web.UI.WebControls
Assembly: System.Web (in system.web.dll)
Syntax
'Declaration
Public Property BackColor As Color
'Usage
Dim instance As Style
Dim value As Color
value = instance.BackColor
instance.BackColor = value
public Color BackColor { get; set; }
public:
property Color BackColor {
Color get ();
void set (Color value);
}
/** @property */
public Color get_BackColor ()
/** @property */
public void set_BackColor (Color value)
public function get BackColor () : Color
public function set BackColor (value : Color)
Eigenschaftenwert
Eine System.Drawing.Color, die die Hintergrundfarbe des Steuerelements darstellt. Der Standardwert ist Color.Empty und gibt an, dass diese Eigenschaft nicht festgelegt ist.
Hinweise
Mit der BackColor-Eigenschaft geben Sie die Hintergrundfarbe des Webserver-Steuerelements an. Diese Eigenschaft wird mit einem System.Drawing.Color-Objekt festgelegt.
Hinweis
Diese Eigenschaft wird nur bei bestimmten Steuerelementen dargestellt. Diese Eigenschaft wird z. B. von Table, Panel, DataGrid, Calendar und ValidationSummary dargestellt. Sie kann auch bei CheckBoxList, RadioButtonList und DataList verwendet werden, wenn deren RepeatLayout-Eigenschaft den Wert RepeatLayout.Table und nicht RepeatLayout.Flow hat.
Im Allgemeinen können in HTML 3.2 nur Steuerelemente eine Hintergrundfarbe anzeigen, die als <table>-Tag dargestellt werden, während das in HTML 4.0 bei fast allen Steuerelementen möglich ist.
In Microsoft Internet Explorer, Version 5 und höher, wird diese Eigenschaft von Steuerelementen unterstützt, die als <span>-Tag dargestellt werden. Dazu zählen Label, alle Validierungssteuerelemente und Listensteuerelemente, deren RepeatLayout-Eigenschaft auf RepeatLayout.Flow festgelegt ist. Dies gilt jedoch nicht für Microsoft Internet Explorer, Version 4.
Beispiel
In diesem Beispiel wird veranschaulicht, wie die Stileigenschaften mehrerer Steuerelemente mit einem Style-Objekt gleichzeitig geändert werden. Wenn sich einer der Style-Eigenschaftenwerte ändert, muss die ApplyStyle-Methode von jedem zugehörigen Steuerelement aufgerufen werden. Beachten Sie, dass nicht alle enthaltenen Steuerelemente alle veranschaulichten Eigenschaften unterstützen. Wenn ein Steuerelement eine bestimmte Eigenschaft nicht unterstützt, ändert sich das Erscheinungsbild des Steuerelements nicht, wenn der Eigenschaftenwert geändert wird.
Hinweis
Im folgenden Codebeispiel wird das Einfachdatei-Codemodell verwendet. Das Beispiel funktioniert möglicherweise nicht, wenn es direkt in eine CodeBehind-Datei kopiert wird. Dieses Codebeispiel muss in eine leere Textdatei mit einer ASPX-Erweiterung kopiert werden. Weitere Informationen zum Web Forms-Codemodell finden Sie unter Codemodell für ASP.NET-Webseiten.
<%@ Page language="VB" AutoEventWireup="true" %>
<%@ Import Namespace="System.Drawing" %>
<%@ Import Namespace="System.Data" %>
<html>
<head>
<script runat="server">
Private Dim primaryStyle As New Style()
Sub Page_Load(sender As Object, e As System.EventArgs)
If Not Page.IsPostBack Then
' Add data to the borderColorList,
' backColorList, and foreColorList controls.
Dim colors As New ListItemCollection()
colors.Add(Color.Black.Name)
colors.Add(Color.Blue.Name)
colors.Add(Color.Green.Name)
colors.Add(Color.Orange.Name)
colors.Add(Color.Purple.Name)
colors.Add(Color.Red.Name)
colors.Add(Color.White.Name)
colors.Add(Color.Yellow.Name)
borderColorList.DataSource = colors
borderColorList.DataBind()
backColorList.DataSource = colors
backColorList.DataBind()
foreColorList.DataSource = colors
foreColorList.DataBind()
' Add data to the borderStyleList control.
Dim styles As New ListItemCollection()
Dim styleType As Type = GetType(BorderStyle)
Dim s As String
For Each s in [Enum].GetNames(styleType)
styles.Add(s)
Next s
borderStyleList.DataSource = styles
borderStyleList.DataBind()
' Add data to the borderWidthList control.
Dim widths As New ListItemCollection()
Dim i As Integer
for i = 0 To 10
widths.Add(i.ToString() & "px")
Next i
borderWidthList.DataSource = widths
borderWidthList.DataBind()
' Add data to the fontNameList control.
Dim names As New ListItemCollection()
names.Add("Arial")
names.Add("Courier")
names.Add("Garamond")
names.Add("Time New Roman")
names.Add("Verdana")
fontNameList.DataSource = names
fontNameList.DataBind()
' Add data to the fontSizeList control.
Dim fontSizes As New ListItemCollection()
fontSizes.Add("Small")
fontSizes.Add("Medium")
fontSizes.Add("Large")
fontSizes.Add("10pt")
fontSizes.Add("14pt")
fontSizes.Add("20pt")
fontSizeList.DataSource = fontSizes
fontSizeList.DataBind()
' Set primaryStyle as the style for each control.
Label1.ApplyStyle(primaryStyle)
ListBox1.ApplyStyle(primaryStyle)
Button1.ApplyStyle(primaryStyle)
Table1.ApplyStyle(primaryStyle)
TextBox1.ApplyStyle(primaryStyle)
End If
End Sub
Sub ChangeBorderColor(sender As Object, e As System.EventArgs)
primaryStyle.BorderColor = _
Color.FromName(borderColorList.SelectedItem.Text)
Label1.ApplyStyle(primaryStyle)
ListBox1.ApplyStyle(primaryStyle)
Button1.ApplyStyle(primaryStyle)
Table1.ApplyStyle(primaryStyle)
TextBox1.ApplyStyle(primaryStyle)
End Sub
Sub ChangeBackColor(sender As Object, e As System.EventArgs)
primaryStyle.BackColor = _
Color.FromName(backColorList.SelectedItem.Text)
Label1.ApplyStyle(primaryStyle)
ListBox1.ApplyStyle(primaryStyle)
Button1.ApplyStyle(primaryStyle)
Table1.ApplyStyle(primaryStyle)
TextBox1.ApplyStyle(primaryStyle)
End Sub
Sub ChangeForeColor(sender As Object, e As System.EventArgs)
primaryStyle.ForeColor = _
Color.FromName(foreColorList.SelectedItem.Text)
Label1.ApplyStyle(primaryStyle)
ListBox1.ApplyStyle(primaryStyle)
Button1.ApplyStyle(primaryStyle)
Table1.ApplyStyle(primaryStyle)
TextBox1.ApplyStyle(primaryStyle)
End Sub
Sub ChangeBorderStyle(sender As Object, e As System.EventArgs)
primaryStyle.BorderStyle = _
CType([Enum].Parse(GetType(BorderStyle), _
borderStyleList.SelectedItem.Text), BorderStyle)
Label1.ApplyStyle(primaryStyle)
ListBox1.ApplyStyle(primaryStyle)
Button1.ApplyStyle(primaryStyle)
Table1.ApplyStyle(primaryStyle)
TextBox1.ApplyStyle(primaryStyle)
End Sub
Sub ChangeBorderWidth(sender As Object, e As System.EventArgs)
primaryStyle.BorderWidth = _
Unit.Parse(borderWidthList.SelectedItem.Text)
Label1.ApplyStyle(primaryStyle)
ListBox1.ApplyStyle(primaryStyle)
Button1.ApplyStyle(primaryStyle)
Table1.ApplyStyle(primaryStyle)
TextBox1.ApplyStyle(primaryStyle)
End Sub
Sub ChangeFont(sender As Object, e As System.EventArgs)
primaryStyle.Font.Name = _
fontNameList.SelectedItem.Text
Label1.ApplyStyle(primaryStyle)
ListBox1.ApplyStyle(primaryStyle)
Button1.ApplyStyle(primaryStyle)
Table1.ApplyStyle(primaryStyle)
TextBox1.ApplyStyle(primaryStyle)
End Sub
Sub ChangeFontSize(sender As Object, e As System.EventArgs)
primaryStyle.Font.Size = _
FontUnit.Parse(fontSizeList.SelectedItem.Text)
Label1.ApplyStyle(primaryStyle)
ListBox1.ApplyStyle(primaryStyle)
Button1.ApplyStyle(primaryStyle)
Table1.ApplyStyle(primaryStyle)
TextBox1.ApplyStyle(primaryStyle)
End Sub
</script>
</head>
<body>
<form id="Form1" runat="server">
<table cellPadding="6" border="0">
<tr>
<td>
<asp:label id="Label1"
Text="Border Properties Example" Runat="server">
<center><br>Label Styles</center>
</asp:label>
</td>
<td>
<asp:button id="Button1" runat="server"
Text="Button Styles">
</asp:button>
</td>
<td>
<asp:listbox id="ListBox1" Runat="server">
<asp:ListItem Value="0" Text="List Item 0">
</asp:ListItem>
<asp:ListItem Value="1" Text="List Item 1">
</asp:ListItem>
<asp:ListItem Value="2" Text="List Item 2">
</asp:ListItem>
</asp:listbox>
</td>
<td>
<asp:textbox id="TextBox1"
Text="TextBox Styles" Runat="server">
</asp:textbox>
</td>
<td>
<asp:table id="Table1" Runat="server">
<asp:TableRow>
<asp:TableCell Text="(0,0)"></asp:TableCell>
<asp:TableCell Text="(0,1)"></asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell Text="(1,0)"></asp:TableCell>
<asp:TableCell Text="(1,1)"></asp:TableCell>
</asp:TableRow>
</asp:table>
</td>
</tr>
<tr>
<td>
<asp:Label Runat="server" Text="Border Color:">
</asp:Label>
<asp:dropdownlist id="borderColorList"
Runat="server" AutoPostBack="True"
OnSelectedIndexChanged="ChangeBorderColor">
</asp:dropdownlist>
<br>
<asp:Label Runat="server" Text="Border Style:">
</asp:Label>
<asp:dropdownlist id="borderStyleList"
Runat="server" AutoPostBack="True"
OnSelectedIndexChanged="ChangeBorderStyle">
</asp:dropdownlist>
<br>
<asp:Label Runat="server" Text="Border Width">
</asp:Label>
<asp:dropdownlist id="borderWidthList"
Runat="server" AutoPostBack="True"
OnSelectedIndexChanged="ChangeBorderWidth">
</asp:dropdownlist>
</td>
<td>
<asp:Label Runat="server" Text="Back Color:">
</asp:Label>
<asp:dropdownlist id="backColorList"
Runat="server" AutoPostBack="True"
OnSelectedIndexChanged="ChangeBackColor">
</asp:dropdownlist>
<br>
<asp:Label Runat="server" Text="Foreground Color:">
</asp:Label>
<asp:dropdownlist id="foreColorList"
Runat="server" AutoPostBack="True"
OnSelectedIndexChanged="ChangeForeColor">
</asp:dropdownlist>
</td>
<td>
<asp:Label Runat="server" Text="Font Name:">
</asp:Label>
<asp:dropdownlist id="fontNameList"
Runat="server" AutoPostBack="True"
OnSelectedIndexChanged="ChangeFont">
</asp:dropdownlist>
<br>
<asp:Label Runat="server" Text="Font Size:">
</asp:Label>
<asp:dropdownlist id="fontSizeList"
Runat="server" AutoPostBack="True"
OnSelectedIndexChanged="ChangeFontSize">
</asp:dropdownlist>
</td>
</tr>
</table>
</form>
</body>
</html>
<%@ Page language="C#" AutoEventWireup="true" %>
<%@ Import Namespace="System.Drawing" %>
<%@ Import Namespace="System.Data" %>
<html>
<head>
<script runat="server">
private Style primaryStyle = new Style();
void Page_Load(object sender, System.EventArgs e)
{
if (!Page.IsPostBack)
{
// Add data to the borderColorList,
// backColorList, and foreColorList controls.
ListItemCollection colors = new ListItemCollection();
colors.Add(Color.Black.Name);
colors.Add(Color.Blue.Name);
colors.Add(Color.Green.Name);
colors.Add(Color.Orange.Name);
colors.Add(Color.Purple.Name);
colors.Add(Color.Red.Name);
colors.Add(Color.White.Name);
colors.Add(Color.Yellow.Name);
borderColorList.DataSource = colors;
borderColorList.DataBind();
backColorList.DataSource = colors;
backColorList.DataBind();
foreColorList.DataSource = colors;
foreColorList.DataBind();
// Add data to the borderStyleList control.
ListItemCollection styles = new ListItemCollection();
Type styleType = typeof(BorderStyle);
foreach (string s in Enum.GetNames(styleType))
{
styles.Add(s);
}
borderStyleList.DataSource = styles;
borderStyleList.DataBind();
// Add data to the borderWidthList control.
ListItemCollection widths = new ListItemCollection();
for (int i = 0; i < 11; i++)
{
widths.Add(i.ToString() + "px");
}
borderWidthList.DataSource = widths;
borderWidthList.DataBind();
// Add data to the fontNameList control.
ListItemCollection names = new ListItemCollection();
names.Add("Arial");
names.Add("Courier");
names.Add("Garamond");
names.Add("Time New Roman");
names.Add("Verdana");
fontNameList.DataSource = names;
fontNameList.DataBind();
// Add data to the fontSizeList control.
ListItemCollection fontSizes = new ListItemCollection();
fontSizes.Add("Small");
fontSizes.Add("Medium");
fontSizes.Add("Large");
fontSizes.Add("10pt");
fontSizes.Add("14pt");
fontSizes.Add("20pt");
fontSizeList.DataSource = fontSizes;
fontSizeList.DataBind();
//Set primaryStyle as the style for each control.
Label1.ApplyStyle(primaryStyle);
ListBox1.ApplyStyle(primaryStyle);
Button1.ApplyStyle(primaryStyle);
Table1.ApplyStyle(primaryStyle);
TextBox1.ApplyStyle(primaryStyle);
}
}
void ChangeBorderColor(object sender, System.EventArgs e)
{
primaryStyle.BorderColor =
Color.FromName(borderColorList.SelectedItem.Text);
Label1.ApplyStyle(primaryStyle);
ListBox1.ApplyStyle(primaryStyle);
Button1.ApplyStyle(primaryStyle);
Table1.ApplyStyle(primaryStyle);
TextBox1.ApplyStyle(primaryStyle);
}
void ChangeBackColor(object sender, System.EventArgs e)
{
primaryStyle.BackColor =
Color.FromName(backColorList.SelectedItem.Text);
Label1.ApplyStyle(primaryStyle);
ListBox1.ApplyStyle(primaryStyle);
Button1.ApplyStyle(primaryStyle);
Table1.ApplyStyle(primaryStyle);
TextBox1.ApplyStyle(primaryStyle);
}
void ChangeForeColor(object sender, System.EventArgs e)
{
primaryStyle.ForeColor =
Color.FromName(foreColorList.SelectedItem.Text);
Label1.ApplyStyle(primaryStyle);
ListBox1.ApplyStyle(primaryStyle);
Button1.ApplyStyle(primaryStyle);
Table1.ApplyStyle(primaryStyle);
TextBox1.ApplyStyle(primaryStyle);
}
void ChangeBorderStyle(object sender, System.EventArgs e)
{
primaryStyle.BorderStyle =
(BorderStyle)Enum.Parse(typeof(BorderStyle),
borderStyleList.SelectedItem.Text);
Label1.ApplyStyle(primaryStyle);
ListBox1.ApplyStyle(primaryStyle);
Button1.ApplyStyle(primaryStyle);
Table1.ApplyStyle(primaryStyle);
TextBox1.ApplyStyle(primaryStyle);
}
void ChangeBorderWidth(object sender, System.EventArgs e)
{
primaryStyle.BorderWidth =
Unit.Parse(borderWidthList.SelectedItem.Text);
Label1.ApplyStyle(primaryStyle);
ListBox1.ApplyStyle(primaryStyle);
Button1.ApplyStyle(primaryStyle);
Table1.ApplyStyle(primaryStyle);
TextBox1.ApplyStyle(primaryStyle);
}
void ChangeFont(object sender, System.EventArgs e)
{
primaryStyle.Font.Name =
fontNameList.SelectedItem.Text;
Label1.ApplyStyle(primaryStyle);
ListBox1.ApplyStyle(primaryStyle);
Button1.ApplyStyle(primaryStyle);
Table1.ApplyStyle(primaryStyle);
TextBox1.ApplyStyle(primaryStyle);
}
void ChangeFontSize(object sender, System.EventArgs e)
{
primaryStyle.Font.Size =
FontUnit.Parse(fontSizeList.SelectedItem.Text);
Label1.ApplyStyle(primaryStyle);
ListBox1.ApplyStyle(primaryStyle);
Button1.ApplyStyle(primaryStyle);
Table1.ApplyStyle(primaryStyle);
TextBox1.ApplyStyle(primaryStyle);
}
</script>
</head>
<body>
<form id="Form1" runat="server">
<table cellPadding="6" border="0">
<tr>
<td>
<asp:label id="Label1"
Text="Border Properties Example" Runat="server">
<center><br>Label Styles</center>
</asp:label>
</td>
<td>
<asp:button id="Button1" runat="server"
Text="Button Styles">
</asp:button>
</td>
<td>
<asp:listbox id="ListBox1" Runat="server">
<asp:ListItem Value="0" Text="List Item 0">
</asp:ListItem>
<asp:ListItem Value="1" Text="List Item 1">
</asp:ListItem>
<asp:ListItem Value="2" Text="List Item 2">
</asp:ListItem>
</asp:listbox>
</td>
<td>
<asp:textbox id="TextBox1"
Text="TextBox Styles" Runat="server">
</asp:textbox>
</td>
<td>
<asp:table id="Table1" Runat="server">
<asp:TableRow>
<asp:TableCell Text="(0,0)"></asp:TableCell>
<asp:TableCell Text="(0,1)"></asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell Text="(1,0)"></asp:TableCell>
<asp:TableCell Text="(1,1)"></asp:TableCell>
</asp:TableRow>
</asp:table>
</td>
</tr>
<tr>
<td>
<asp:Label Runat="server" Text="Border Color:">
</asp:Label>
<asp:dropdownlist id="borderColorList"
Runat="server" AutoPostBack="True"
OnSelectedIndexChanged="ChangeBorderColor">
</asp:dropdownlist>
<br>
<asp:Label Runat="server" Text="Border Style:">
</asp:Label>
<asp:dropdownlist id="borderStyleList"
Runat="server" AutoPostBack="True"
OnSelectedIndexChanged="ChangeBorderStyle">
</asp:dropdownlist>
<br>
<asp:Label Runat="server" Text="Border Width">
</asp:Label>
<asp:dropdownlist id="borderWidthList"
Runat="server" AutoPostBack="True"
OnSelectedIndexChanged="ChangeBorderWidth">
</asp:dropdownlist>
</td>
<td>
<asp:Label Runat="server" Text="Back Color:">
</asp:Label>
<asp:dropdownlist id="backColorList"
Runat="server" AutoPostBack="True"
OnSelectedIndexChanged="ChangeBackColor">
</asp:dropdownlist>
<br>
<asp:Label Runat="server" Text="Foreground Color:">
</asp:Label>
<asp:dropdownlist id="foreColorList"
Runat="server" AutoPostBack="True"
OnSelectedIndexChanged="ChangeForeColor">
</asp:dropdownlist>
</td>
<td>
<asp:Label Runat="server" Text="Font Name:">
</asp:Label>
<asp:dropdownlist id="fontNameList"
Runat="server" AutoPostBack="True"
OnSelectedIndexChanged="ChangeFont">
</asp:dropdownlist>
<br>
<asp:Label Runat="server" Text="Font Size:">
</asp:Label>
<asp:dropdownlist id="fontSizeList"
Runat="server" AutoPostBack="True"
OnSelectedIndexChanged="ChangeFontSize">
</asp:dropdownlist>
</td>
</tr>
</table>
</form>
</body>
</html>
Plattformen
Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.
Versionsinformationen
.NET Framework
Unterstützt in: 2.0, 1.1, 1.0
Siehe auch
Referenz
Style-Klasse
Style-Member
System.Web.UI.WebControls-Namespace
System.Drawing.Color
Table
Panel-Klasse
DataGrid-Klasse
Calendar-Klasse
ValidationSummary
CheckBoxList-Klasse
RadioButtonList-Klasse
DataList-Klasse
RepeatLayout-Enumeration
Weitere Ressourcen
ASP.NET-Webserversteuerelemente und CSS-Formatvorlagen
ASP.NET-Webserversteuerelemente und Browserfunktionen