实例代码-判断是否安装app的代码

public static boolean isAppInstalled(Context context,String packageName){final PackageManager packageManager = context.getPackageManager();   List<PackageInfo> pInfos = packageManager.getInstalledPackages(0);        List<String> pNames = new ArrayList<String>();        if(pInfos != null){            for(int i = 0; i < pInfos.size(); i++){                String pname  = pInfos.get(i).packageName;                pNames.add(pname);            }        }   return pNames.contains(packageName);}