HttpCapabilitiesBase.RequiresSpecialViewStateEncoding Property

 

Gets a value indicating whether the browser requires VIEWSTATE values to be specially encoded.

Namespace:   System.Web.Configuration
Assembly:  System.Web (in System.Web.dll)

public virtual bool RequiresSpecialViewStateEncoding { get; }

Property Value

Type: System.Boolean

true if the browser requires VIEWSTATE values to be specially encoded; otherwise, false. The default is false.

HTTP is a stateless protocol, and VIEWSTATE is one mechanism used to persist client changes across multiple requests. Each control on a Web page contains a ViewState property, which represents the accumulation of any changes made by the client. In a Web Forms page, these changes are encoded in postback data as the value of an HTML <input> element with a type attribute of hidden. For example:

<input type="hidden" name="__VIEWSTATE" value="t0PH_u56?cDxleHQ7P=" />

If true, non-alphabetic characters in the VIEWSTATE value will not be sent correctly by the browser, nor by an intermediate gateway. To correct this, server-control adapters replace non-alphabetic characters in the VIEWSTATE value with ones that do not require encoding in HTTP requests.

The following code example shows how to determine whether the browser requires VIEWSTATE values to be specially encoded.

<%@ 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).RequiresSpecialViewStateEncoding)
        {
            labelText = "Browser requires view state values to be specially encoded.";
        }
        else
        {
            labelText = "Browser does not require view state values to be specially encoded.";
        }

        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>

.NET Framework
Available since 2.0
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