Uncaught Error: Error calling method on NPObject.

1、错误描述

Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. 
For more help, check http://xhr.spec.whatwg.org/.

获取到第一个值：undefined

Uncaught Error: Error calling method on NPObject.
Uncaught 
Error: Error calling method on NPObject.

2、错误原因

function windowOnload() {
	Report.LoadFromURL("student.grf?date="+(new Date().getTime()));
	$.ajax({
		url:"param/isPrint",
		type:"get",
		dataType:"json",
		async:false,
	}).done(function(resp){
	   if(dt.success==false){
			return;
	   }
	   var isPrint=resp.isPrint;

	   $.ajax({
		    url:"student/stu/findStu",
			type:"get",
			dataType:"json",
			data:{},
			async:false
		}).done(function(data){
		   if(!data){
			   return;
		   }
		   var report = JSON.stringify(data);
		   Report.LoadDataFromAjaxRequest(report,"application/json;charset=UTF-8");
		   Report.Print(isPrint);
		});
	});
}

        利用Grid++Report制作报表时，是否打开打印窗口，利用一个参数isPrint来控制；当isPrint=true，显示打印窗口，否则不显示。但是，如果查询出来的结果没有这个参数，并且直接在Print(isPrint)使用，这时会报错Error calling method on NPObject

3、解决办法

     在Report.Print(isPrint)使用这个参数前，添加判断

function windowOnload() {
	Report.LoadFromURL("student.grf?date="+(new Date().getTime()));
	$.ajax({
		url:"param/isPrint",
		type:"get",
		dataType:"json",
		async:false,
	}).done(function(resp){
	   if(dt.success==false){
			return;
	   }
	   var isPrint=resp.isPrint;

	   $.ajax({
		    url:"student/stu/findStu",
			type:"get",
			dataType:"json",
			data:{},
			async:false
		}).done(function(data){
		   if(!data){
			   return;
		   }
		   var report = JSON.stringify(data);
		   Report.LoadDataFromAjaxRequest(report,"application/json;charset=UTF-8");
		   Report.Print(isPrint?true:false);
		});
	});
}