在发送intent启动activity之前判断是否有activity接收

通过packagemanager()的queryIntentAActivities(intent,0)的返回list<ResolveInfo>长度来判断
具体代码如下：

PackageManager packageManager = getPackageManager();
List<ResolveInfo> activities = packageManager.queryIntentActivities(intent, 0);
boolean isIntentSafe = activities.size() > 0;