Ajax is returned with responseXML, and the client (IE) cannot analyze xml Problems

An IE found a problem in processing the returned result of an ajax request during work. The record is as follows:

 

Ajax is returned with responseXML, and the client (IE) cannot analyze xml Problems
When ajax is displayed using the alert method of js to display the returned results with responseText, an xml structure document is displayed. However, when xml is parsed using responseXML, the length of all nodes is 0, the key to this issue is that the server does not specify the correct document format:

Response. setContentType ("text/xml; charset = UTF-8"); (correct)
Response. setContentType ("text/html; charset = UTF-8"); (error)
At the same time, pay attention to response. setContentType ("text/xml; charset = UTF-8"); the location of this sentence should be at the beginning, that is, the beginning of the response creation.