無法在外部存儲器上創建文件Android

Question

我想創建一個.txt文件並將其存儲在Android手機的外部存儲器中。我向Android Manifest添加了權限。當我運行代碼時，它不會給我任何錯誤，但是文件永遠不會被創建。不知道我做錯了什麼。

public void createExternalStoragePrivateFile(String data) { 
    // Create a path where we will place our private file on external 
    // storage. 
    File file = new File(myContext.getExternalFilesDir(null), "state.txt"); 

    try { 

     FileOutputStream os = null; 
     OutputStreamWriter out = null; 
     os = myContext.openFileOutput(data, Context.MODE_PRIVATE); 
     out = new OutputStreamWriter(os); 
     out.write(data); 
     os.close(); 

     if(hasExternalStoragePrivateFile()) { 
      Log.w("ExternalStorageFileCreation", "File Created"); 
     } else { 
      Log.w("ExternalStorageFileCreation", "File Not Created"); 
     } 

    } catch (IOException e) { 
     // Unable to create file, likely because external storage is 
     // not currently mounted. 
     Log.w("ExternalStorage", "Error writing " + file, e); 
    } 
} 

Answer 1

File file = new File(myContext.getExternalFilesDir(null), "state.txt"); 
try { 

    FileOutputStream os = new FileOutputStream(file, true); 
    OutputStreamWriter out = new OutputStreamWriter(os); 
     out.write(data); 
    out.close(); 
} 

Answer 2

，你需要一個適當的權限：

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

Answer 3

我可以使用下面的代碼來創建外部存儲的文件：

public void createExternalStoragePrivateFile(String data) { 
    // Create a path where we will place our private file on external 
    // storage. 
    File file = new File(myContext.getExternalFilesDir(null), "state.txt"); 


    try { 

     FileOutputStream os = new FileOutputStream(file); 
     OutputStreamWriter out = new OutputStreamWriter(os); 

     out.write(data); 
     out.close(); 

     if(hasExternalStoragePrivateFile()) { 
      Log.w("ExternalStorageFileCreation", "File Created"); 
     } else { 
      Log.w("ExternalStorageFileCreation", "File Not Created"); 
     } 

    } catch (IOException e) { 
     // Unable to create file, likely because external storage is 
     // not currently mounted. 
     Log.w("ExternalStorage", "Error writing " + file, e); 
    } 
}