有沒有辦法從活動的另一個活動恢復

Question

我有一個使用意圖去到活動B.有時活動A也開始另一個活動的活動一結束就知道了，活動C.有沒有一種方式活動A知道在這些活動完成時從哪個活動（B或C）重新啓動？ 謝謝先進。

Answer 1

使用靜態變量來存儲最後一個活動開始，所以在恢復活性的，您可以檢查它。

Answer 2

你可以使用方法startActivityForResult而不是startActivity來啓動你的活動B或C.如果B或C比返回標識本身，你可以讀取它的結果。

Answer 3

private boolean isB = false; 

public void startActivity(Class<?> activityName){ 
    Intent intent = new Intent(this, activityName); 
    isB = activityName.getName().equals(B.class.getName()); 
    startActivity(intent); 
} 

Answer 4

像Juanjo維加說， 使用activitylifecycle的方法來做到這一點..... 看一看方法.... LifecycleMethods-android

你可以設置一個全局變量或在您想要獲得通知的活動的onResume（）方法中使用某些（按照您的邏輯）。它的onPause觸發邏輯後的onResume（）將CAL ...

設立全局，您可以使用singleTons或Application class

Answer 5

退房你的自我，你會很容易地知道

public class MainActivity extends Activity { 

    Button clikBtn; 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     Log.e("onCreate", "111111111"); 

     Toast.makeText(MainActivity.this,"onCreate...",Toast.LENGTH_LONG).show(); 
     setContentView(R.layout.activity_main); 

     clikBtn = (Button)findViewById(R.id.clickBtn); 

     /*clikBtn.setOnClickListener(new OnClickListener() { 
      @Override 
      public void onClick(View view) { 

      } 
     });*/ 
    } 

    public void clickButton(View v){ 
     Intent intent = new Intent(MainActivity.this,SecondActivity.class); 
     startActivity(intent); 
    } 

    @Override 
    protected void onStart() { 
     super.onStart(); 
     Toast.makeText(MainActivity.this,"onStart...",Toast.LENGTH_LONG).show(); 
     Log.e("onStart","999999999"); 
    } 

    @Override 
    protected void onPause() { 
     super.onPause(); 
     Toast.makeText(MainActivity.this,"onPause...",Toast.LENGTH_LONG).show(); 
     Log.e("onPause", "222222222"); 
     // notify("onPause"); 
    } 

    @Override 
    protected void onResume() { 
     super.onResume(); 
     Toast.makeText(MainActivity.this,"onResume...",Toast.LENGTH_LONG).show(); 
     Log.e("onResume", "333333333"); 
     //notify("onResume"); 
    } 

    @Override 
    protected void onStop() { 
     super.onStop(); 
     Toast.makeText(MainActivity.this,"onStop...",Toast.LENGTH_LONG).show(); 
     Log.e("onStop", "444444444"); 
     //notify("onStop"); 
    } 

    @Override 
    protected void onDestroy() { 
     super.onDestroy(); 
     Toast.makeText(MainActivity.this,"onDestroy...",Toast.LENGTH_LONG).show(); 
     Log.e("onDestroy", "55555555"); 
     //notify("onDestroy"); 
    } 

    @Override 
    protected void onRestart() { 
     super.onRestart(); 
     Toast.makeText(MainActivity.this,"onRestart...",Toast.LENGTH_LONG).show(); 
     Log.e("onRestart","66666666"); 
    } 

    @Override 
    protected void onRestoreInstanceState(Bundle savedInstanceState) { 
     super.onRestoreInstanceState(savedInstanceState); 
     Toast.makeText(MainActivity.this,"onRestoreInstanceState...",Toast.LENGTH_LONG).show(); 
     Log.e("onRestoreInstanceState", "777777777"); 
     //notify("onRestoreInstanceState"); 
    } 

    @Override 
    protected void onSaveInstanceState(Bundle outState) { 
     super.onSaveInstanceState(outState); 
     Toast.makeText(MainActivity.this,"onSaveInstanceState...",Toast.LENGTH_LONG).show(); 
     Log.e("onSaveInstanceState", "8888888888"); 
     //notify("onSaveInstanceState"); 
    } 


} 

Answer 6

從活動A，調用下面的方法，假設你有兩個按鈕，並在他們的點擊啓動活動B或活動C：

public void StartOtherActivityB() { 
     Intent aIntent = new Intent(LauncherActivity.this, OtherActivityB.class); 
     startActivityForResult(aIntent, REQUEST_ACTIVITY_B); 


} 



public void StartOtherActivityC() { 
    Intent aIntent = new Intent(LauncherActivity.this, OtherActivityC.class); 
    startActivityForResult(aIntent, REQUEST_ACTIVITY_C); 


} 

和IMP lement onActivityResult（）方法如下

@Override 
protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
    super.onActivityResult(requestCode, resultCode, data); 

    if(requestCode == REQUEST_ACTIVITY_B){ 

     //class restarted from ACTIVITY_B 

    }else if (requestCode ==REQUEST_ACTIVITY_C){ 

     //class restarted from ACTIVITY_C 

    } 
}