if (plus.os.name == "iOS") {  
                plus.runtime.openURL("weixin://scanqrcode")  

            } else if (plus.os.name == "andriod") {  
                var Intent = plus.android.importClass("android.content.Intent");  
                var ComponentName = plus.android.importClass('android.content.ComponentName')  
                var intent = new Intent();  
                intent.setComponent(new ComponentName("com.tencent.mm", "com.tencent.mm.ui.LauncherUI"));  
                intent.putExtra("LauncherUI.From.Scaner.Shortcut", true);  
                intent.setFlags(335544320);  
                intent.setAction("android.intent.action.VIEW");  
                var main = plus.android.runtimeMainActivity();  
                main.startActivity(intent);  
            }