UC知道关于xmlhttprequest.readystate的一个问题
来源：百度知道 编辑：UC知道 时间：2024/06/28 01:29:21
在回调函数中监测xmlhttprequest.readystate,
使用alert(xmlhttprequest.readystate)
点击按钮之后，我发现有时候1，2，3，4都出现 ，
但有时候只有1，就停住了，然后我刷新页面就出现2，4
这是为什么
请高人指点
//come from Ajax hack书
onreadystatechange
Callback function; the function assigned to this property is called whenever readyState changes.
readyState
Number;
0 means uninitialized, open( ) has not yet been called;
1 means loading, send( ) has not been called;
2 means loaded, send( ) has been called, and headers/status are available;
3 means interactive, responseText holds partial data;
4 means completed.
responseText
string; the plain text of the response.
responseXML
DOM Document object; an XML return value.
status
Response status code, such as 200 (Okay) or 404 (Not Found).
statusText
string; the text associated with the HTTP response status.
The methods supported include:
abort( )
void; cancels the HTTP request.
getAllResponseHeaders( )
string; returns all of the res