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);
}