無法從內部根存儲中讀取文件

Question

我有一個紮根Android手機，我的客戶端有8個平板電腦（Unrooted）。他們將在明天晚上使用它來從Android平板電腦做一些比賽。我製作了一個應用程序，可以從我的內部存儲器的根文件夾中的自定義文件夾中讀取文件，該文件夾可以在我的根移動設備上運行良好，但無法在客戶端無根內存片上運行。

根據他們所有的文件將高達3GB存儲在內部存儲器。我被卡住了，他們真的需要幫助，並建議我應該怎麼做？

public class MainActivity extends AppCompatActivity { 

    Button button; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     getSupportActionBar().hide(); 
     setContentView(R.layout.activity_main); 

     ImageView welcomeLogo = (ImageView) findViewById(R.id.welcomeLogo); 
     welcomeLogo.setImageResource(R.drawable.iba); 

     //Get the text file 
     File dir = new File(Environment.getExternalStorageDirectory().getAbsolutePath()); 
     File file = new File(dir, "lvi/names.txt"); 
     //Read text from file 
     StringBuilder text = new StringBuilder(); 
     try { 
      BufferedReader br = new BufferedReader(new FileReader(file)); 
      String line; 
      while ((line = br.readLine()) != null) { 
       text.append(line); 
       text.append('\n'); 
      } 
      br.close(); 

      //Find the view by its id 
      TextView tv = (TextView)findViewById(R.id.welcomeJudge); 
      //Set the text 
      tv.setText("Welcome " + text.toString()); 
     } 
     catch (IOException e) { 
      //You'll need to add proper error handling here 
     } 

     //When the enter button is click goto the dashboard activity 
     button = (Button) findViewById(R.id.btnEnter); 
     button.setOnClickListener(new OnClickListener() { 
      public void onClick(View arg0) { 
       Intent dashboardIntent = new Intent(MainActivity.this, dashboard.class); 
       startActivity(dashboardIntent); 
      } 
     }); 
    } 
} 

我艙單權限

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

Answer 1

的Android 6.0（API等級23），你必須設置運行權限

if (Build.VERSION.SDK_INT >= 23 && 
      ContextCompat.checkSelfPermission(context, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED && 
      ContextCompat.checkSelfPermission(context, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) { 

     ActivityCompat.requestPermissions((BaseActivity) context, 
       new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE}, 
       MY_PERMISSIONS_REQUEST_READ_AND_WRITE_SDK); 
    } else { 
     ReadMethod();//your custom method 


    } 

onRequestPermissionsResult

@Override 
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) { 
super.onRequestPermissionsResult(requestCode, permissions, grantResults); 

switch (requestCode) { 
    case MY_PERMISSIONS_REQUEST_READ_AND_WRITE_SDK: 

     if (grantResults.length > 0 
       && grantResults[0] == PackageManager.PERMISSION_GRANTED) { 

      ReadMethod();//your custom method 
     } 
     break; 


    } 
}