Android如何判断手机里是否安装了某个应用

public static boolean isAppInstalled(Context context) {
PackageManager pm;
if ((pm = context.getApplicationContext().getPackageManager()) == null) {
return false;
}
List<PackageInfo> packages = pm.getInstalledPackages(0);
for (PackageInfo info : packages) {
String name = info.packageName.toLowerCase(Locale.ENGLISH);
if ("**.**.**".equals(name)) { //应用包名 eg:com.sina.weibo
return true;
}
}
return false;
}