如何在（A，B）活動中管理'startActivityForResult'和'ActivityResult'？

Question

我有兩個活動A和B. 從A，我通過startActivityForResult向B發送一些數據，並從B獲取ActivityResult的回覆。 現在，如果我想處理髮送給我的任何B，然後將數據發送回B，那麼我還必須在B中使用startActivityForResult和ActivityResult。

它的聊天（來回）實物A和B.

任何幫助之間的通信中，將不勝感激。

Answer 1

我已經寫了使用LocalBroadcastReceiver到activities

活動A之間發送數據的代碼：

public class A extends AppCompatActivity { 

    @Override 
    protected void onCreate(@Nullable Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_a); 

     // Registering LocalBroadcastReceiver to receiver data from B 
     LocalBroadcastManager.getInstance(this).registerReceiver(mReceiverA, new IntentFilter("activity_a")); 
     findViewById(R.id.btnStartB).setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Intent i = new Intent(A.this, B.class); 
       i.putExtra("key_string", "Value"); // add stuffs to be sent to Activity B 
       startActivity(i); 
      } 
     }); 
    } 

    @Override 
    protected void onDestroy() { 
     // Don't forget to unregister receiver 
     LocalBroadcastManager.getInstance(this).unregisterReceiver(mReceiverA); 
     super.onDestroy(); 
    } 

    BroadcastReceiver mReceiverA = new BroadcastReceiver() { 
     @Override 
     public void onReceive(final Context context, Intent intent) { 
      // Get data from Intent, which we got from Activity B 
      if (intent.hasExtra("key_string")) { 
       Toast.makeText(context, intent.getStringExtra("key_string"), Toast.LENGTH_SHORT).show(); 
       // Here you can process the data, and send result to Activity B 
       // Adding delay temporary, so that Toast will be visible on by one 
       new Handler().postDelayed(new Runnable() { 
        @Override 
        public void run() { 
         Intent i = new Intent("activity_b"); 
         i.putExtra("key_string", "Value Of String From A"); 
         LocalBroadcastManager.getInstance(context).sendBroadcast(i); 
        } 
       }, 600); 
      } 
     } 
    }; 
} 

活動B：

public class B extends AppCompatActivity { 

    @Override 
    protected void onCreate(@Nullable Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_b); 

     // Registering LocalBroadcastReceiver to receiver data from A 
     LocalBroadcastManager.getInstance(this).registerReceiver(mReceiverB, new IntentFilter("activity_b")); 

     findViewById(R.id.button2).setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Intent i = new Intent("activity_a"); 
       i.putExtra("key_string", "Value Of String From B"); 
       LocalBroadcastManager.getInstance(B.this).sendBroadcast(i); 
      } 
     }); 
    } 

    @Override 
    protected void onDestroy() { 
     // Don't forget to unregister receiver 
     LocalBroadcastManager.getInstance(this).unregisterReceiver(mReceiverB); 
     super.onDestroy(); 
    } 

    BroadcastReceiver mReceiverB = new BroadcastReceiver() { 
     @Override 
     public void onReceive(Context context, Intent intent) { 
      // Get data from Intent, which we got from Activity B 
      if (intent.hasExtra("key_string")) { 
       Toast.makeText(context, intent.getStringExtra("key_string"), Toast.LENGTH_SHORT).show(); 
      } 
     } 
    }; 
} 

希望這有助於:-)

Answer 2

Intent yourFirstAct= new Intent(firstAct.this,second.class); 
yourFirstAct.putExtra("",""); 
startActivitForResult(yourFirstAct); 

在第一個活動，

public void onAcitivityResult(....){ 
super(); 
} 

在你的第二個活動

，當你做了，

Intent yoursecAct= new Intent(); 
yourSecAct.putExtra("",""); 
setResult(yourSecAct); 
finish(); 

如果您在片段的手段做startActivityResult（），

您的片段mainActivity必須返回超級（）

public void onAcitivityResult(...){super()}