通过

HttpCapabilitiesBase.CanRenderEmptySelects 属性

  • 参考

定义

命名空间:
System.Web.Configuration
程序集:
System.Web.dll

获取一个值，该值指示浏览器是否支持空 HTML <select> 元素。

public:
 virtual property bool CanRenderEmptySelects { bool get(); };
public virtual bool CanRenderEmptySelects { get; }
member this.CanRenderEmptySelects : bool
Public Overridable ReadOnly Property CanRenderEmptySelects As Boolean

属性值

Boolean

如果浏览器支持空的 HTML <select> 元素，则为 true；否则为 false。 默认值为 true。

示例

下面的代码示例演示如何确定浏览器是否支持空 HTML <select> 元素。

<%@ page language="C#"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
    void Page_Load(Object Sender, EventArgs e)
    {
        CheckBrowserCaps();
    }

    void CheckBrowserCaps()
    {
        String labelText = "";
        System.Web.HttpBrowserCapabilities myBrowserCaps = Request.Browser;
        if (((System.Web.Configuration.HttpCapabilitiesBase)myBrowserCaps).CanRenderEmptySelects)
        {
            labelText = "Browser supports empty select markup language statements.";
        }
        else
        {
            labelText = "Browser does not support empty select markup language statements.";
        }

        Label1.Text = labelText;
    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>Browser Capabilities Sample</title>
</head>
<body>
    <form runat="server" id="form1">
        <div>
            Browser Capabilities:
            <p/><asp:Label ID="Label1" Runat="server" />
        </div>
    </form>
</body>
</html>

<%@ page language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
    Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
        CheckBrowserCaps()
    End Sub

    Function CheckBrowserCaps()

        Dim labelText As String = ""
        Dim myBrowserCaps As System.Web.HttpBrowserCapabilities = Request.Browser
        If (CType(myBrowserCaps, System.Web.Configuration.HttpCapabilitiesBase)).CanRenderEmptySelects Then
            labelText = "Browser supports empty select markup language statements."
        Else
            labelText = "Browser does not support empty select markup language statements."
        End If

        Label1.Text = labelText

    End Function 'CheckBrowserCaps
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>Browser Capabilities Sample</title>
</head>
<body>
    <form runat="server" id="form1">
        <div>
            Browser Capabilities:
            <p/><asp:Label ID="Label1" Runat="server" />
        </div>
    </form>
</body>
</html>

适用于