調用同一個活動的多個實例和多個活動

Question

我有三個活動。 MainActivity，ActivityB和ActivityC。在活動A和B中，兩個活動中都有兩個按鈕源和目標。在Activity C中有一個數據列表。按鈕被點擊時（源或目標）從活動A和B兩者的活動呼叫活動Ç 爲活動A碼被以下

public class MainActivity extends Activity { 

TextView source,destination; 
Button sendSource,sendDestination,btnTob; 
String src,des,activity,checksrc,checkdes; 

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

    source=(TextView)findViewById(R.id.tv_rcvDataA); 
    destination=(TextView)findViewById(R.id.tv_rcvDataAa); 
    sendSource=(Button)findViewById(R.id.btn_sendA); 
    sendDestination=(Button)findViewById(R.id.btn_sendAa); 
    btnTob=(Button)findViewById(R.id.btn_toB); 

    sendSource.setText("source"); 
    sendDestination.setText("destination"); 
    src=sendSource.getText().toString(); 
    des=sendDestination.getText().toString(); 

    activity=getClass().getSimpleName(); 
    sendSource.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      Intent send= new Intent(MainActivity.this,ActivityC.class); 
      send.putExtra("source",src); 
      send.putExtra("Activity",activity); 
      startActivity(send); 
     } 
    }); 
    sendDestination.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      Intent senda= new Intent(MainActivity.this,ActivityC.class); 
      senda.putExtra("destination",des); 
      senda.putExtra("Activity",activity); 
      startActivity(senda); 

     } 
    }); 

    btnTob.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      Intent movetoB= new Intent(MainActivity.this,ActivityB.class); 
      startActivity(movetoB); 
      finish(); 
     } 
    }); }} 

和活動B代碼是

public class ActivityB extends Activity { 

TextView sourceB,destinationB; 
Button sendSourceB,sendDestinationB; 

String src,des,activity,checksrc,checkdes; 

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

    sourceB=(TextView)findViewById(R.id.tv_rcvDataB); 
    destinationB=(TextView)findViewById(R.id.tv_rcvDataBa); 
    sendSourceB=(Button)findViewById(R.id.btn_sendB); 
    sendDestinationB=(Button)findViewById(R.id.btn_sendDataBa); 
    activity=getClass().getSimpleName(); 

    sendDestinationB.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      Intent senda= new Intent(ActivityB.this,ActivityC.class); 
      senda.putExtra("destination",src); 
      senda.putExtra("Activity",activity); 
      startActivity(senda); 
     } 
    }); 

    sendSourceB.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      Intent send= new Intent(ActivityB.this,ActivityC.class); 
      send.putExtra("source",src); 
      send.putExtra("Activity",activity); 
      startActivity(send); 
     } 
    });}} 

現在如何檢查activityC哪些活動正在調用此活動以及哪個buttonclicklistener正在調用intent

Answer 1

在onCreate或之後的任何時間在Activity-C中調用該方法時，應該執行以下操作：

Intent intent = getIntent(); 
if (intent != null) { 
    String activity = intent.getStringExtra("Activity"); 
    String src = intent.getStringExtra("source"); 
    // Do something with those values 
} 

Answer 2

您需要通過Intent.putExtra()發送值以確定什麼值和什麼活動。請記住，你需要設置密鑰爲Intent.putExtra()第一個參數，如

intent.putExtra(THIS_IS_THE_KEY, THIS_IS_YOUR_VALUE); 

您需要創建這樣的事情：

// This is the key for your putExtra 
// you need to create this as global variable. 
public static final String FROM_KEY = "FROM"; 
public static final String ACTIVITY_KEY = "ACTIVITY"; 
public static final boolean IS_FROM_SOURCE = true; 

// This is a sample to send data to Activity C 
// where the activity caller is B and from source 
Intent senda= new Intent(ActivityB.this,ActivityC.class); 
senda.putExtra(FROM_KEY, IS_FROM_SOURCE); 
senda.putExtra(ACTIVITY_KEY,"activity_a"); 

然後在你的活動C，你需要接受意圖額外。 您可以在活動onCreate()獲得的價值，這樣的事情：

Bundle extras = getIntent().getExtras(); 
boolean from = extras.getBoolean(FROM_KEY); 
String act = extras.getString(ACTIVITY_KEY); 

// do something here if from activity a 
if(act.equals("activity_a")) { 
    if(IS_FROM_SOURCE) { 
    // do something if from source 
    } else { 
    // do something if from destination. 
    } 
} else { // if from activity a 
    if(IS_FROM_SOURCE) { 
    // do something if from source 
    } else { 
    // do something if from destination. 
    } 
}