Question

以下代码段在IE7中无效吗？

var http = new XMLHttpRequest();
var url = 'http://my_site.com/';
var obj = createJsonParamsObj();
http.open("POST", url, true);
http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
http.send(JSON.stringify(obj));

从文档中可以看出new XMLHttpRequest()应该有效，但是由于我无法测试它（仅在兼容模式下）而有疑问，所以也许我最好使用new ActiveXObject。

Answer 1

谷歌中的小搜索将为您的基本问题提供一个很好的答案

/*
   Provide the XMLHttpRequest constructor for Internet Explorer 5.x-6.x:
   Other browsers (including Internet Explorer 7.x-9.x) do not redefine
   XMLHttpRequest if it already exists.

   This example is based on findings at:
   http://blogs.msdn.com/xmlteam/archive/2006/10/23/using-the-right-version-of-msxml-in-internet-explorer.aspx
*/
if (typeof XMLHttpRequest === "undefined") {
  XMLHttpRequest = function () {
    try { return new ActiveXObject("Msxml2.XMLHTTP.6.0"); }
    catch (e) {}
    try { return new ActiveXObject("Msxml2.XMLHTTP.3.0"); }
    catch (e) {}
    try { return new ActiveXObject("Microsoft.XMLHTTP"); }
    catch (e) {}
    // Microsoft.XMLHTTP points to Msxml2.XMLHTTP and is redundant
    throw new Error("This browser does not support XMLHttpRequest.");
  };
}

或

/** 
 * Gets an XMLHttpRequest. For Internet Explorer 6, attempts to use MSXML 6.0,
 * then falls back to MXSML 3.0.
 * Returns null if the object could not be created. 
 * @return {XMLHttpRequest or equivalent ActiveXObject} 
 */ 
function getXHR() { 
  if (window.XMLHttpRequest) {
    // Chrome, Firefox, IE7+, Opera, Safari
    return new XMLHttpRequest(); 
  } 
  // IE6
  try { 
    // The latest stable version. It has the best security, performance, 
    // reliability, and W3C conformance. Ships with Vista, and available 
    // with other OS's via downloads and updates. 
    return new ActiveXObject('MSXML2.XMLHTTP.6.0');
  } catch (e) { 
    try { 
      // The fallback.
      return new ActiveXObject('MSXML2.XMLHTTP.3.0');
    } catch (e) { 
      alert('This browser is not AJAX enabled.'); 
      return null;
    } 
  } 
}

参考：http://en.wikipedia.org/wiki/XMLHttpRequest和http://www.webmasterworld.com/javascript/4027629.htm

Answer 2

来自jQuery source code：

/* Microsoft failed to properly
 * implement the XMLHttpRequest in IE7 (can't request local files),
 * so we use the ActiveXObject when it is available
 * Additionally XMLHttpRequest can be disabled in IE7/IE8 so
 * we need a fallback.
 */

最好在IE7中使用ActiveXObject，如下所示：

new window.ActiveXObject("Microsoft.XMLHTTP")

Answer 3

example from Microsoft几乎完全按照您的代码执行操作：

var oReq = new XMLHttpRequest();
oReq.open("POST", sURL, false);
oReq.setRequestHeader("Content-Type", "text/xml");
oReq.send(sRequestBody);

从这里开始，我甚至可以设想的唯一可能的失败点是支持application/x-www-form-urlencoded的特定Content-Type值的错误，我非常怀疑这是一个现存问题。< / p>

还要记住包含JSON库，因为IE7不包含本机JSON对象。

XMLHttpRequest浏览器支持

3 个答案: