title: How to write file to internal storage(/storage/sdcard1)?
body: <p>My phone(Ienovo A320t) has 3 storage device as below:</p>
  
  <p>System(<code>/data</code>), Internal(<code>/storage/sdcard1</code>) and External(<code>/storage/sdcard0</code>)</p>
  
  <p>I can read or write external storage(<code>/storage/sdcard0</code>), my app works very well. But when I try to write something to internal storage(<code>/storage/sdcard1</code>), it always fails, no file was created, and also this process did not throw any exception. How can I get a permission to access internal storage(<code>/storage/sdcard1</code>)?</p>
  
  <p>Here are some permission I defined in <code>AndroidManifest.xml</code>:</p>
  
  <pre><code>&lt;uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /&gt;
  &lt;uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /&gt;
  &lt;uses-permission android:name="android.permission.NFC" /&gt;
  &lt;uses-permission android:name="android.permission.read_phone_state" /&gt;
  &lt;uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" /&gt;
  </code></pre>