Get back to a fragment from an Activity

问题:

I have three fragment in an Activity C. they are behaving as tabs. I have to go from a fragment to a new Activity X. Now i want to come back to fragment from Activity X.

I have override onBackPressed but don't know how to go back to fragment/not fragmentActivity from an Activity.

if i want to go back to an Activity to another activity i override on back pressed and using intent call that actvity..

i want to do some thing like this .. this code is for coming back to previous activity

@Override
public void onBackPressed()
{

    Intent intent = new Intent(CurrentActivity.this,ActivityYouLikeToGo.class);

    intent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);

    startActivity(intent);
}

thanks in Advance..

回答1:

You can add a TAG (A string name for the fragment basically) and then load the fragment using findFragmentByTag().

Google documentation for findFragmentByTag() is here.

Or you can also addToBackStack() while calling the fragment from FragmentTransaction, doc link here. from google docs:

"By calling addToBackStack(), the replace transaction is saved to the back stack so the user can reverse the transaction and bring back the previous fragment by pressing the Back button."

回答2:

First, Override the back press to goto the activity where the fragments are :-

@Override
public void onBackPressed()
{

    Intent intent = new Intent(CurrentActivity.this,ActivityYouLikeToGo.class);

    intent.putExtra("Check",1);
    startActivity(intent);
}

then goto the ActivityYouLikeToGo.java file and in onCreate do this:-

Intent intent = getIntent();
String s1 = intent.getStringExtra("Check");

if(s1.equals("1"))
  {
s1 = "";
Fragment fragment = new YOURFRAMENTNAME();
if (fragment != null) {
            FragmentManager fragmentManager = getFragmentManager();
            fragmentManager.beginTransaction()
                    .replace(R.id.frame_container, fragment).commit();
  }
}

回答3:

Simplest way :

@Override
onBackPressed(){
finish();
}

回答4:

if i want to go back to an Activity to another activity i override on back pressed and using intent call that actvity

Normally, if you want to go back you don't have to do something. Pressing the device's hardware Back button will take you to the previous activity with the corresponding tab already opened.

回答5:

You can start the activity that you are navigating to using startActivityForResult() and then while coming back to the previous activity you set the result.In the activity that you are coming back to,show the fragment depending on the resultcode. You can accomplish this task by hiding all the fragments that you dont want to show. This can work even if you are going to another activity from another fragment.

回答6:

In the activity you have started from your fragment, you can do the following:

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        //do whatever you want here
        finish();
        return true;
    }

That works for me :)

回答7:

This code works in my case. I just make an Onclick method to the button . the code is below:I made onclick method clickForFriends in Button and Id is backFriendsList, And I use android.support.v4.app.Fragment class. This method should take back from new Activity to the fragment from the Activity was launched and this method should be in the Activity after the onCreate method

 public void clickedForFriends(View v){
    if (v.getId() == R.id.backFriendsList){
       onBackPressed();
    }
}

回答8:

viewPager.setCurrentItem(tabPosition);

This solution did wonders for me.