Implementation method of using jsonp cross-domain access under jquery_jquery

$.ajax({
async:false,
url: '', // Cross-domain URL
type: 'GET',
dataType: 'jsonp',
jsonp: 'jsoncallback', //Default callback
data: mydata, // Request data
timeout: 5000,
beforeSend: function(){ //jsonp method is not triggered. The reason may be that if dataType is specified as jsonp, it is no longer an ajax event.
},
success: function (json) { //The callback function predefined by jquery on the client side. After successfully obtaining the json data on the cross-domain server, this callback function will be dynamically executed
if(json.actionErrors.length!= 0){
alert(json.actionErrors);
}

},
complete: function(XMLHttpRequest, textStatus){

},
error: function(xhr){
//Jsonp mode this method is not triggered
//Request error handling
alert("Request error (please check the correlation network status.)");
}
});

$.getJSON(url "?callback=?",
function(json){

});