我写一个Android应用程序，存储了大量的媒体文件。他们不是类型（以及太多太多），以扰乱用户的通知或其他媒体目录，但他们也必须由用户更新，所以我不能把他们的资源。我可以用getExternalFilesDir，以取得该SD卡的路径，但我只想要做的，如果应用程序本身被安装在SD卡。如果应用程序被安装在内部，我希望把媒体在内部存储器中。

I am writing an android app that stores a lot of media files. They are not the type (and are far too many) to clutter up the users notification or other media directories, but they also must be user-updatable, so I can't put them in the resources. I can use getExternalFilesDir to get a path on the sdcard, but I only want to do that if the app itself is installed on the sdcard. If the app is installed internally, I want to put the media in the internal memory.

那么，如何能确定我的应用程序是在内部或外部存储器运行？

So how can I determine if my app is running in internal or external memory?

推荐答案

您可以使用PackageManager得到ApplicationInfo，并从那里检查标志的FLAG_EXTERNAL_STORAG​​E。

You could use PackageManager to get the ApplicationInfo, and from there check the "flags" for FLAG_EXTERNAL_STORAGE.

http://developer.android.com/intl/de/reference/android/content/pm/ApplicationInfo.html#FLAG_EXTERNAL_STORAGE

下面是一个简单的例子，我作了演示：

Here's a quick example I made to demonstrate:

@Override
   public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);

      PackageManager pm = getPackageManager();
      try {
         PackageInfo pi = pm.getPackageInfo("com.totsp.helloworld", 0);
         ApplicationInfo ai = pi.applicationInfo;
         // this only works on API level 8 and higher (check that first)
         Toast
                  .makeText(
                           this,
                           "Value of FLAG_EXTERNAL_STORAGE:"
                                    + ((ai.flags & ApplicationInfo.FLAG_EXTERNAL_STORAGE) == ApplicationInfo.FLAG_EXTERNAL_STORAGE),
                           Toast.LENGTH_LONG).show();
      } catch (NameNotFoundException e) {
         // do something
      }
   }

不过，根据您的情况（你是否拥有所有的媒体的前面，或者用户获取/创建它，因为他们使用的应用程序），您可能希望把它放在外部存储不管。大尺寸的内部应用程序是令人难以接受，许多用户（以及大量的内部媒体可能会使其巨大的）。

Still, depending on your situation (whether or not you have all the "media" up front, or the user gets/creates it as they use the app), you may want to put it on the external storage regardless. A large size internal app is frowned upon by many users (and a lot of internal media would probably make it huge).