打包后,runtimeMainActivity对象方法报错

        var Intent,main;  

        function plusReady(){  
            if(plus.os.name == 'Android'){  
                Intent = plus.android.importClass("android.content.Intent");  
                main   = plus.android.runtimeMainActivity();                      
            }  
        }  
        if(window.plus){  
            plusReady();  
        }else{  
            document.addEventListener("plusready",plusReady,false);  
        }         

        function share(){  
            var intent = new Intent(Intent.ACTION_SEND);  
                intent.setType("text/plain");  
                intent.putExtra(Intent.EXTRA_SUBJECT, "易家");  
                intent.putExtra(Intent.EXTRA_TEXT, '测试内容');  
                intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);  
                main.startActivity(Intent.createChooser(intent,"分享"));                        
        }