The list of files on the memory card is not returned?

Question

Android

The list of files on the memory card is not returned?
I wrote in the manifest:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

I get a link:

String path = Environment.getExternalStorageDirectory().getAbsolutePath();

trying to get a list of memory card files

File f = new File(path);
    if(f.listFiles()!=null)
    {
      File[] files = f.listFiles();
      Arrays.sort(files);
      for ( File aFile : files ){
        if ( aFile.isDirectory() ) {
          if(dir_opened(aFile.getPath())){
            FileDir.add(aFile.getName());
          }
        }
      }
    }

but File f is null. I check on a real device. What's wrong?

Answer 1

You are probably running on Android 6. Permissions from this version must be requested at runtime. Here is an article for you to study.