asp.net IE11 dopostback is null or undefined 为空或未定义

个人认为这个问题一般是未按规范书写导致，但懒人嘛就有懒办法。

页面重构一般可以解决此问题，但是对于不便重写的情形，这里仍然有一个解决办法。

解决方法：

1.将文件ie11.browser拷贝到C:WindowsMicrosoft.NETFrameworkv4.0.30319ConfigBrowsers下，因操作系统及.netframework版本不同，路径可能会有所差异。
2.以管理员身份启动cmd.exe, 切换到目录C:WindowsMicrosoft.NETFrameworkv4.0.30319下。
3.输入命令“aspnet_regbrowsers -i”后回车，命令不包括引号部分。
4.输入命令“iisreset”后回车，命令不包括引号部分。
5.等待命令执行完成后，IE应该就可以了。

ie11.browser为text文件，内容如下：

<browsers>
  <browser id="IE11" parentID="Mozilla">
    <identification>
        <userAgent match="Trident/7.0; rv:(?'version'(?'major'd+)(.(?'minor'd+)?)(?'letters'w*))(?'extra'[^)]*)" />
        <userAgent nonMatch="IEMobile" />
    </identification>

    <capture>
        <userAgent match="Trident/(?'layoutVersion'd+)" />
    </capture>

    <capabilities>
        <capability name="browser"              value="IE" />
        <capability name="layoutEngine"         value="Trident" />
        <capability name="layoutEngineVersion"  value="${layoutVersion}" />
        <capability name="extra"                value="${extra}" />
        <capability name="isColor"              value="true" />
        <capability name="letters"              value="${letters}" />
        <capability name="majorversion"         value="${major}" />
        <capability name="minorversion"         value="${minor}" />
        <capability name="screenBitDepth"       value="8" />
        <capability name="type"                 value="IE${major}" />
        <capability name="version"              value="${version}" />
    </capabilities>
</browser>

<!-- Mozilla/5.0 (Windows NT 6.3; Trident/7.0; rv:11,0) like Gecko -->
<browser id="IE110" parentID="IE11">
    <identification>
        <capability name="majorversion" match="11" />
    </identification>

    <capabilities>
        <capability name="ecmascriptversion"    value="3.0" />
        <capability name="jscriptversion"       value="5.6" />
        <capability name="javascript"           value="true" />
        <capability name="javascriptversion"    value="1.5" />
        <capability name="msdomversion"         value="${majorversion}.${minorversion}" />
        <capability name="w3cdomversion"        value="1.0" />
        <capability name="ExchangeOmaSupported" value="true" />
        <capability name="activexcontrols"      value="true" />
        <capability name="backgroundsounds"     value="true" />
        <capability name="cookies"              value="true" />
        <capability name="frames"               value="true" />
        <capability name="javaapplets"          value="true" />
        <capability name="supportsCallback"     value="true" />
        <capability name="supportsFileUpload"   value="true" />
        <capability name="supportsMultilineTextBoxDisplay" value="true" />
        <capability name="supportsMaintainScrollPositionOnPostback" value="true" />
        <capability name="supportsVCard"        value="true" />
        <capability name="supportsXmlHttp"      value="true" />
        <capability name="tables"               value="true" />
        <capability name="supportsAccessKeyAttribute"    value="true" />
        <capability name="tagwriter"            value="System.Web.UI.HtmlTextWriter" />
        <capability name="vbscript"             value="true" />
    </capabilities>
</browser>
</browsers>