Style.BackColor Proprietà
Definizione
Importante
Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.
Ottiene o imposta il colore di sfondo del controllo server Web.
public:
property System::Drawing::Color BackColor { System::Drawing::Color get(); void set(System::Drawing::Color value); };[System.ComponentModel.Bindable(true)]
[System.ComponentModel.TypeConverter(typeof(System.Web.UI.WebControls.WebColorConverter))]
public System.Drawing.Color BackColor { get; set; }[System.ComponentModel.TypeConverter(typeof(System.Web.UI.WebControls.WebColorConverter))]
public System.Drawing.Color BackColor { get; set; }[<System.ComponentModel.Bindable(true)>]
[<System.ComponentModel.TypeConverter(typeof(System.Web.UI.WebControls.WebColorConverter))>]
member this.BackColor : System.Drawing.Color with get, set[<System.ComponentModel.TypeConverter(typeof(System.Web.UI.WebControls.WebColorConverter))>]
member this.BackColor : System.Drawing.Color with get, setPublic Property BackColor As ColorValore della proprietà
Oggetto Color che rappresenta il colore di sfondo del controllo. Il valore predefinito è Empty, che indica che la proprietà non è impostata.
- Attributi
Esempio
In questo esempio viene illustrato come utilizzare un Style oggetto per modificare le proprietà di stile di più controlli contemporaneamente. Ogni volta che uno dei valori della Style proprietà cambia, ogni controllo deve chiamare il relativo ApplyStyle metodo. Si noti che non tutti i controlli inclusi supportano tutte le proprietà illustrate. Se un controllo non supporta una proprietà specifica, l'aspetto del controllo non verrà modificato quando il valore della proprietà viene modificato.
Nota
L'esempio di codice seguente usa il modello di codice a file singolo e potrebbe non funzionare correttamente se copiato direttamente in un file code-behind. Questo esempio di codice deve essere copiato in un file di testo vuoto con estensione aspx. Per altre informazioni sul modello di codice Web Forms, vedere Web Forms ASP.NET Page Code Model.
<!-- -->
<!-- -->
<%@ Page Language="C#" %>
<%@ 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 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();
//<Snippet4>
// 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();
//</Snippet4>
// 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("Times 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);
}
}
//<Snippet5>
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);
}
//</Snippet5>
//<Snippet6>
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);
}
//</Snippet6>
//<Snippet7>
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);
}
//</Snippet7>
//<Snippet8>
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);
}
//</Snippet8>
//<Snippet9>
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);
}
//</Snippet9>
//<Snippet10>
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);
}
//</Snippet10>
//<Snippet11>
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);
}
//</Snippet11>
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</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>
<%@ 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()
'<Snippet4>
' 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()
'</Snippet4>
' 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
'<Snippet5>
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
'</Snippet5>
'<Snippet6>
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
'</Snippet6>
'<Snippet7>
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
'</Snippet7>
'<Snippet8>
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
'</Snippet8>
'<Snippet9>
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
'</Snippet9>
'<Snippet10>
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
'</Snippet10>
'<Snippet11>
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
'</Snippet11>
</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>
Commenti
Utilizzare la BackColor proprietà per specificare il colore di sfondo del controllo server Web. Questa proprietà viene impostata utilizzando un System.Drawing.Color oggetto .
Nota
Questa proprietà eseguirà il rendering solo per determinati controlli. Ad esempio, Table, Panel, DataGrid, Calendare ValidationSummary eseguirà il rendering di questa proprietà. Funzionerà anche per CheckBoxListe RadioButtonListDataList se la relativa RepeatLayout proprietà è RepeatLayout.Table, e non RepeatLayout.Flow.
In generale, solo i controlli di cui viene eseguito il rendering come <table> tag possono visualizzare un colore di sfondo in HTML 3.2, mentre quasi tutti i controlli possono essere in HTML 4.0.
Per i controlli di cui viene eseguito il rendering come <span> tag (inclusi Label, tutti i controlli di convalida e i controlli elenco con la relativa RepeatLayout proprietà impostata su RepeatLayout.Flow), questa proprietà funzionerà in Microsoft Internet Explorer versione 5 o successiva, ma non per Microsoft Internet Explorer versione 4.
Si applica a
Vedi anche
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