Android开发中判断手机是否安装了QQ或者微信

public static boolean isWeixinAvilible(Context context) {     final PackageManager packageManager = context.getPackageManager();// 获取packagemanager     List<PackageInfo> pinfo = packageManager.getInstalledPackages(0);// 获取所有已安装程序的包信息     if (pinfo != null) {       for (int i = 0; i < pinfo.size(); i++) {         String pn = pinfo.get(i).packageName;         if (pn.equals("com.tencent.mm")) {           return true;         }       }     }     return false;   }   /**    * 判断qq是否可用    *     * @param context    * @return    */   public static boolean isQQClientAvailable(Context context) {     final PackageManager packageManager = context.getPackageManager();     List<PackageInfo> pinfo = packageManager.getInstalledPackages(0);     if (pinfo != null) {       for (int i = 0; i < pinfo.size(); i++) {         String pn = pinfo.get(i).packageName;         if (pn.equals("com.tencent.mobileqq")) {           return true;         }       }     }     return false;   }