callback的返回函数，onSuccess是返回成功的意思，onFailure是返回失败的意思，
onLoading是返回加载时的要做的事情，onLoaded是返回加载后时要做的事情，那其他的是什么意思呢？ 请教大神，如果之前这四个有问题的也请大神解答
0: (Uninitialized) the send( ) method has not yet been invoked.
3: (Interactive) the response is being parsed.
4: (Completed) the response has been parsed, is ready for harvesting.
0 － （未初始化）还没有调用send()方法
3 － （交互）正在解析响应内容
4 － （完成）响应内容解析完成，可以在客户端调用了
thank you very much
ajax就5种状态，不知道你哪来的8种。那些个onLoadSuccess都是插件依据底层ajax的状态生成的
0: (Uninitialized) the send( ) method has not yet been invoked.
1: (Loading) the send( ) method has been invoked, request in progress.
2: (Loaded) the send( ) method has completed, entire response received.
3: (Interactive) the response is being parsed.
4: (Completed) the response has been parsed, is ready for harvesting.
0 － （未初始化）还没有调用send()方法
1 － （载入）已调用send()方法，正在发送请求
2 － （载入完成）send()方法执行完成，已经接收到全部响应内容
3 － （交互）正在解析响应内容
4 － （完成）响应内容解析完成，可以在客户端调用了