HttpCapabilitiesBase.SupportsUncheck Property

Reference

Definition

Namespace:: System.Web.Configuration

Assembly:: System.Web.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Gets a value indicating whether the clearing of a checked HTML <input type=checkbox> element is reflected in postback data.

public:
 virtual property bool SupportsUncheck { bool get(); };

public virtual bool SupportsUncheck { get; }

member this.SupportsUncheck : bool

Public Overridable ReadOnly Property SupportsUncheck As Boolean

Property Value

Boolean

true if the clearing of a checked HTML <input type=checkbox> element is reflected in postback data; otherwise, false. The default is true.

Examples

The following code example shows how to determine whether the clearing of a checked HTML <input type=checkbox> element is reflected in postback data.

<%@ 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).SupportsUncheck)
        {
            labelText = "Browser reflects the unchecking of a checked HTML CHECKBOX element in postback data.";
        }
        else
        {
            labelText = "Browser does not reflect the unchecking of a checked HTML CHECKBOX element in postback data.";
        }

        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)).SupportsUncheck Then
            labelText = "Browser reflects the unchecking of a checked HTML CHECKBOX element in postback data."
        Else
            labelText = "Browser does not reflect the unchecking of a checked HTML CHECKBOX element in postback data."
        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>

Remarks

If false, the value of the checked attribute of HTML <input type=checkbox> elements is omitted from postback data.

Applies to

共用方式為