Experiences in Ajax asynchronous calling of methods with parameters in Web Services

I was very depressed last night. I encountered a problem that was not solved for one night. It was always unsuccessful when I used ajax to asynchronously call a web service with parameters, because the status value of XMLHttpRequest is never equal to 200. I thought I was using Ajax to call the Web service in a wrong way. I used to refer to a previously written method without parameters, and found that it was correct. I finally found the problem this morning (--# It often takes a lot of time for cainiao to solve a problem. You're not experienced !!).

I added this sentence before the send method.Code: XMLHTTP. setRequestHeader ('content-type', 'application/X-WWW-form-urlencoded'); it's okay... depressing... it seems that this sentence must be added to the method with parameters to asynchronously call the web service. Otherwise, XMLHTTP. status is not 200. then... that is, the processing function ''' cannot be executed ''''

This is my experience, and I hope it will help you. At least don't be tripped up by a minor problem when you are a beginner. Remember to stick ''''