如何获得以前的活动？

Question

我们在活动A和我们这样做下面的代码：

if (previousActivity){ // what method calling the previous activity ? 
         Intent intent = new Intent(
           LoginActivity.this, 
           CmdEndActivity.class); // I want to go in CmdEndActivity 
         intent.putExtra("username", user); 
         intent.putExtra("useremail", email); 
         startActivity(intent); 
         finish(); 

         overridePendingTransition(R.anim.push_left_in, R.anim.push_left_out); 

        } 
        else { 
         Intent intent = new Intent(
           LoginActivity.this, 
           Reservation4.class); // I want to go in Reservation4 
         intent.putExtra("username", user); 
         intent.putExtra("useremail", email); 
         startActivity(intent); 
         finish(); 

         overridePendingTransition(R.anim.push_left_in, R.anim.push_left_out); 

        } 

这可能吗？

Answer 1

试试这个

@Override 
    public boolean onOptionsItemSelected(MenuItem item) { 

     if (item.getItemId() == android.R.id.home) { 
      onBackPressed(); 
      return true; 
     } 
     return false; 

    } 

Answer 2

您可以使用IntentputExtra的活动名称传递到另一个。然后在目的地活动使用getIntent并检查这是否等于Activity 1或Activity 2。类似下面：

Intent intent = new Intent(this, Activity2.class); 
intent.putExtra("activity_name", "Activity 1"); 
startActivity(intent); 

而且在活动2检查额外价值：

String activity_name = getIntent().getStringExtra("activity_name"); 
if(activity_name.equal("Activity 1")){ 
    //... goto Activity B 
}else if(activity_name.equal("Activity 2")){ 
    // ... goto Activity C 
}