將數據從片段傳遞到新活動

Question

我試圖將數據從我的主活動傳遞到我的相機活動，傳遞到相機片段，然後返回到我的主活動。我希望用戶能夠保存他們在主要活動中輸入的信息，以便在完成使用相機時保留它們。

在我主要活動，我傳遞了如下的意圖額外的相機活動：

（注：本作品）

Intent cameraIntent = new Intent(MainActivity.this, CameraActivity.class); 
    cameraIntent.putExtra("description" , editTextDescription.getText().toString()); 
    cameraIntent.putExtra("category" , editTextCategory.getText().toString()); 
    cameraIntent.putExtra("notes" , editTextNotes.getText().toString()); 
MainActivity.this.startActivity(cameraIntent); 

我則在收到臨時演員我的相機活動成功，並將它們傳遞到我的相機片段：

（注：本作品）

Intent intent = getIntent(); 

if (intent.getExtras() != null) { 

    description = intent.getExtras().getString("description"); 
    category = intent.getExtras().getString("category"); 
    notes = intent.getExtras().getString("notes"); 

    } 

if (null == savedInstanceState) { 

    CameraFragment cameraFragment = new CameraFragment(); 

    Bundle bundle = new Bundle(); 

    bundle.putString("description", description); 
    bundle.putString("category", category); 
    bundle.putString("notes", notes); 
    cameraFragment.setArguments(bundle); 

    Log.v(TAG, "Here is the bundle: " + bundle.toString()); 

    getFragmentManager().beginTransaction() 
     .replace(R.id.container, cameraFragment.newInstance()) 
     .add(cameraFragment, bundle.toString()) 
     .commit(); 

    } 

在我相機片段，我收到了包在我onCreateView如下：

（注：本作品）

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 

    if (getArguments() != null) { 

     description = getArguments().getString("description"); 
     category = getArguments().getString("category"); 
     notes = getArguments().getString("notes"); 
     Log.v(TAG, "Here are your arguments from the camera activity: " + description + " " + category + " " + notes); 

    } 

    else { 
     Log.v(TAG, "Your arguments are null"); 
    } 

    return inflater.inflate(R.layout.fragment_camera, container, false); 
} 

所有這些交易都正確執行，並且至此我已正確收到所有信息。我現在的目標是獲取信息，並將其傳回主要活動。

ISSUE **

case R.id.doneButton: { 

    Intent intent = new Intent(getActivity(), MainActivity.class); 
      intent.putExtra("description", description); 
      intent.putExtra("category", category); 
      intent.putExtra("notes", notes); 
      Log.v(TAG, "Here are the extras going back to the Main Activity " + description + " " + category + " " + notes); 
    startActivity(intent); 
      break; 

     } 

但是，我不能把我在片段接收到的信息，和其他地方使用的變量。我嘗試在除了onCreateView之外的方法中嘗試獲取參數，然後在將其他參數傳遞迴主要活動之前使用該方法。我也嘗試在我的onClick開關，大小寫方法中嘗試獲取參數，但是，當我嘗試將數據發送回我的主要活動時，它總是返回null，因爲它沒有接受它在參數中收到的內容，而是使用我之前聲明的字符串。

private String description; 
private String category; 
private String notes; 

有沒有辦法把我在爭論中我相機片段接收到的數據，並使用它們的onCreateView方法之外，並送他們回到我主要活動？

Answer 1

你爲什麼不在你的Fragment中做一個'get'方法。

cameraFragment.getXXXX(); 

Answer 2

我有一種改寫你的代碼，這個工程。

public class MainActivity extends AppCompatActivity { 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     Intent cameraIntent = new Intent(MainActivity.this, CameraActivity.class); 
     cameraIntent.putExtra("description" , "description"); 
     cameraIntent.putExtra("category" , "category"); 
     cameraIntent.putExtra("notes" , "notes"); 
     startActivity(cameraIntent); 
    } 
} 

public class CameraActivity extends Activity{ 

    private String description,category,notes; 

    @Override 
    protected void onCreate(@Nullable Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_camera); 
     Intent intent = getIntent(); 

     if (intent.getExtras() != null) { 

      description = intent.getExtras().getString("description"); 
      category = intent.getExtras().getString("category"); 
      notes = intent.getExtras().getString("notes"); 

     } 

     if (null == savedInstanceState) { 

      CameraFragment cameraFragment = new CameraFragment(); 

      Bundle bundle = new Bundle(); 

      bundle.putString("description", description); 
      bundle.putString("category", category); 
      bundle.putString("notes", notes); 
      cameraFragment.setArguments(bundle); 

      Log.v(TAG, "Here is the bundle: " + bundle.toString()); 

      getFragmentManager().beginTransaction() 
        .replace(R.id.container, cameraFragment) 
        .commit(); 

     } 
    } 
} 

即使在doneButton的onclick的3串越來越填充

public class CameraFragment extends Fragment{ 

    private String description,category,notes; 
    private Button doneButton; 

    @Nullable 
    @Override 
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) { 
     View view = inflater.inflate(R.layout.fragment_camera, container, false); 
     if (getArguments() != null) { 

      description = getArguments().getString("description"); 
      category = getArguments().getString("category"); 
      notes = getArguments().getString("notes"); 
      Log.v("CameraFragment", "Here are your arguments from the camera activity: " + description + " " + category + " " + notes); 

     } 

     else { 
      Log.v("CameraFragment", "Your arguments are null"); 
     } 
     doneButton = view.findViewById(R.id.doneButton); 
     doneButton.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       Intent intent = new Intent(getActivity(), MainActivity.class); 
       intent.putExtra("description", description); 
       intent.putExtra("category", category); 
       intent.putExtra("notes", notes); 
       Log.v("CameraFragment", "Here are the extras going back to the Main Activity " + description + " " + category + " " + notes); 
       startActivity(intent); 
      } 
     }); 
     return view; 
    } 

}