通过

Unit 结构

  • 项目

表示长度度量。

**命名空间:**System.Web.UI.WebControls
**程序集:**System.Web（在 system.web.dll 中）

语法

声明
<SerializableAttribute> _
Public Structure Unit
用法
Dim instance As Unit

[SerializableAttribute] 
public struct Unit

[SerializableAttribute] 
public value class Unit

/** @attribute SerializableAttribute() */ 
public final class Unit extends ValueType

JScript 支持使用结构，但不支持进行新的声明。

备注

Unit 结构表示可以用任何与 HTML 兼容的大小单位表示的长度度量。UnitType 枚举列出可以表示的度量单位。Unit 由 BorderWidth 和 Height 等属性用来表示属性的长度或宽度。例如，可以将 Web 服务器控件的 BorderWidth 属性设置为表示 5 个像素的 Unit。

提示

Unit 类只能表示 -32768 和 32767 之间的值。

使用 Value 属性确定度量长度。使用 Type 属性来确定度量单位。通过使用 Parse、Percentage、Pixel 和 Point 方法，可以将其他数据类型转换为 Unit。

有关 Unit 的实例的初始属性值列表，请参见 Unit 构造函数。

主题 位置
如何：设置 Web 服务器控件的单位属性 在 Visual Studio 中生成 ASP .NET Web 应用程序
如何：设置 Web 服务器控件的单位属性 在 Visual Studio 中生成 ASP .NET Web 应用程序
如何：设置 Web 服务器控件的单位属性 生成 ASP .NET Web 应用程序

示例

下面的代码示例演示如何使用 Style 对象一次更改多个控件的样式属性。每次更改 Style 属性值中的一个值时，各个控件必须调用其 ApplyStyle 方法。请注意，并非所有控件都支持演示的所有属性。如果某个控件不支持某个特定的属性，则当该属性值更改时，该控件的外观不会更改。

<%@ 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>

线程安全

此类型的任何公共静态（Visual Basic 中的 Shared）成员都是线程安全的，但不保证所有实例成员都是线程安全的。

平台

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 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

版本信息

.NET Framework

受以下版本支持：2.0、1.1、1.0

请参见

参考

Unit 成员
System.Web.UI.WebControls 命名空间
UnitType
Value
Type
Parse
Percentage
Pixel
Point

其他资源

ASP.NET Web 服务器控件和 CSS 样式