android检测手机是否安装某个app

public static boolean isAvilible(Context context, String packageName){
    //获取packagemanager
    final PackageManager packageManager = context.getPackageManager();
    //获取所有已安装程序的包信息
    List<PackageInfo> packageInfos = packageManager.getInstalledPackages(0);
    //用于存储所有已安装程序的包名
    List<String> packageNames = new ArrayList<String>();
    //从pinfo中将包名字逐一取出，压入pName list中
    if(packageInfos != null){
        for(int i = 0; i < packageInfos.size(); i++){
            String packName = packageInfos.get(i).packageName;
            packageNames.add(packName);
        }
    }
    //判断packageNames中是否有目标程序的包名，有TRUE，没有FALSE
    return packageNames.contains(packageName);
}