1、调用计算器
记录一下,方便下次使用
PackageInfo pack = getAllApps("Calculator","calculator");
if(pack!=null){
Intent intent = activity.getPackageManager().getLaunchIntentForPackage(pack.packageName);
startActivity(intent);
}else {
Toast.makeText(activity,"不存在计算器",Toast.LENGTH_SHORT).show();
}