createXHR(): 创建兼容浏览器的XMLHttpRequest 

 1 function createXHR()
 2 {
 3     if (typeof XMLHttpRequest != "undefined")
 4     {
 5         return new XMLHttpRequest();
 6     } // end if
 7     else if (window.ActiveXObject)
 8     {
 9         var aVersions = ["MSXML2.XMLHttp.6.0", "MSXML2.XMLHttp.3.0"];
10         for (var i = 0; i < aVersions.length; ++i)
11         {
12             try
13             {
14                 var oXHR = new ActiveXObject(aVersions[i]);
15                 return oXHR;
16             } // end try
17             catch (oError)
18             {
19                 // do nothing
20             } // end catch
21             
22         } // end for
23         
24     } // end else if
25     
26     throw new Error("XMLHttp object could not be created.")
27     
28 } // end createXHR();

 

来源: professional ajax 2nd edition, page39

 

1 function createXHR()
2 {
3   try { return new XMLHttpRequest(); } catch (e) {}
4   try { return new ActiveXObject("Msxml2.XMLHTTP.6.0"); } catch (e) {}
5   try { return new ActiveXObject("Msxml2.XMLHTTP.3.0"); } catch (e) {}
6   try { return new ActiveXObject("Msxml2.XMLHTTP"); } catch (e) {}
7   try { return new ActiveXObject("Microsoft.XMLHTTP"); } catch (e) {}
8   return null;
9 } // end createXHR()

来源: ajax完全手册中文版 62页

 

 

posted @ 2013-09-27 16:00  我的百科全书  阅读(1696)  评论(0)  编辑  收藏  举报