jquery $.getJSON() cross-domain request_jquery

1. The same domain name and other requests can be the same
js:

Copy code The code is as follows:

var url="http://localhost:2589/a.ashx";
$(function(){
$.getJSON(url,function(data){
alert (data.Name);
})
});

The server returns a string:
{"Name":"loogn","Age":23}
2,
js under different domain names:

Copy code The code is as follows:

var url="http://localhost:2589/a.ashx?callback=?";
$(function(){
$.getJSON(url,function(data){
alert (data .Name);
})
});

The server returns the string:
jQuery1706543070425920333_1324445763158({"Name":"loogn","Age":23})
The returned string is a function called "jQuery1706543070425920333_1324445763158", and the parameters are {"Name":"loogn","Age":23}.
In fact, this very long function name is the function of callback=? in the request path. I think it should be like this: The $.getJSON method generates a name that references the callback method, replace it? . The above request will become
http://localhost:2589/a.ashx?callback=jQuery1706543070425920333_1324445763158&_=1324445763194. The server needs to process it when returning json, such as:

Copy code The code is as follows:

string cb = context.Request["callback"];
context.Response.Write(cb "(" json ")");

The parameter name callback can also be replaced by jsoncallback. I think it is for fear of conflict. jsoncallback should be detected first, and callback should not be detected again (not tested!!)
? It can also be a specific function name, so the callback function cannot be anonymous. Use? Generation is just a convenience provided by jQuery for our general operations.