Style.BackColor Property
Gets or sets the background color of the Web server control.
Assembly: System.Web (in System.Web.dll)
Property Value
Type: System.Drawing.ColorA System.Drawing.Color that represents the background color of the control. The default is Color.Empty, which indicates that this property is not set.
Use the BackColor property to specify the background color of the Web server control. This property is set using a System.Drawing.Color object.
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This property will render only for certain controls. For example, Table, Panel, DataGrid, Calendar, and ValidationSummary will render this property. It will also work for CheckBoxList, RadioButtonList and DataList if their RepeatLayout property is RepeatLayout.Table, and not RepeatLayout.Flow. |
In general, only controls that render as a <table> tag can display a background color in HTML 3.2, whereas almost any control can in HTML 4.0.
For controls that render as a <span> tag (including Label, all validation controls, and list controls with their RepeatLayout property set to RepeatLayout.Flow), this property will work in Microsoft Internet Explorer version 5 or later, but not for Microsoft Internet Explorer version 4.
This example demonstrates how to use a Style object to change the style properties of multiple controls at once. Each time one of the Style property values changes, each control must call its ApplyStyle method. Note that not all the controls included support all the properties demonstrated. If a control does not support a particular property, the appearance of the control will not change when the property value is changed.
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The following code sample uses the single-file code model and may not work correctly if copied directly into a code-behind file. This code sample must be copied into an empty text file that has an .aspx extension. For more information on the Web Forms code model, see ASP.NET Web Forms Page Code Model. |
<%@ Page Language="VB" %> <%@ Import Namespace="System.Drawing" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> Private primaryStyle As New Style() Sub Page_Load(ByVal sender As Object, ByVal 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("Times 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(ByVal sender As Object, ByVal 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(ByVal sender As Object, ByVal 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(ByVal sender As Object, ByVal 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(ByVal sender As Object, ByVal 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(ByVal sender As Object, ByVal 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(ByVal sender As Object, ByVal 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(ByVal sender As Object, ByVal 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> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server"> <title>Applied Style Example</title> </head> <body> <form id="form1" runat="server"> <div> <table cellpadding="6" border="0"> <tr> <td rowspan="10" style="border:solid 1px Gray"> <p> <asp:label id="Label1" Text="Border Properties Example" Runat="server"> Label Styles </asp:label> </p> <p> <asp:button id="Button1" runat="server" Text="Button Styles"> </asp:button> </p> <p> <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> </p> <p> <asp:textbox id="TextBox1" Text="TextBox Styles" Runat="server"> </asp:textbox> </p> <p> <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> </p> </td> <td align="right"> <asp:Label ID="Label2" runat="server" AssociatedControlID="borderColorList" Text="Border Color:"> </asp:Label> </td> <td> <asp:dropdownlist id="borderColorList" Runat="server" AutoPostBack="True" OnSelectedIndexChanged="ChangeBorderColor"> </asp:dropdownlist> </td> </tr> <tr> <td align="right"> <asp:Label ID="Label3" Runat="server" AssociatedControlID="borderStyleList" Text="Border Style:"> </asp:Label> </td> <td> <asp:dropdownlist id="borderStyleList" Runat="server" AutoPostBack="True" OnSelectedIndexChanged="ChangeBorderStyle"> </asp:dropdownlist> </td> </tr> <tr> <td align="right"> <asp:Label ID="Label4" Runat="server" AssociatedControlID="borderWidthList" Text="Border Width"> </asp:Label> </td> <td> <asp:dropdownlist id="borderWidthList" Runat="server" AutoPostBack="True" OnSelectedIndexChanged="ChangeBorderWidth"> </asp:dropdownlist> </td> </tr> <tr> <td align="right"> <asp:Label ID="Label5" Runat="server" AssociatedControlID="backColorList" Text="Back Color:"> </asp:Label> </td> <td> <asp:dropdownlist id="backColorList" Runat="server" AutoPostBack="True" OnSelectedIndexChanged="ChangeBackColor"> </asp:dropdownlist> </td> </tr> <tr> <td align="right"> <asp:Label ID="Label6" Runat="server" AssociatedControlID="foreColorList" Text="Foreground Color:"> </asp:Label> </td> <td> <asp:dropdownlist id="foreColorList" Runat="server" AutoPostBack="True" OnSelectedIndexChanged="ChangeForeColor"> </asp:dropdownlist> </td> </tr> <tr> <td align="right"> <asp:Label ID="Label7" Runat="server" AssociatedControlID="fontNameList" Text="Font Name:"> </asp:Label> </td> <td> <asp:dropdownlist id="fontNameList" Runat="server" AutoPostBack="True" OnSelectedIndexChanged="ChangeFont"> </asp:dropdownlist> </td> </tr> <tr> <td align="right"> <asp:Label ID="Label8" Runat="server" AssociatedControlID="fontSizeList" Text="Font Size:"> </asp:Label> </td> <td> <asp:dropdownlist id="fontSizeList" Runat="server" AutoPostBack="True" OnSelectedIndexChanged="ChangeFontSize"> </asp:dropdownlist> </td> </tr> </table> </div> </form> </body> </html>
Available since 1.1
