【轉】asp.net 項目在 IE 11 下出現 「__doPostBack」未定義 的解決辦法

解決方法：

在項目根目錄 App_Browsers 下新建 瀏覽器文件(.browser)，讓其與IE11的 UserAgent 匹配，使 .net framework 認識這是一個已知的瀏覽器，能夠正常地向客戶端輸出腳本。 
在文件裏輸入如下內容，保存便可。

<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>