Develop Reference

Calling ShowViewModel on activity, does not show Child fragment

Following the MvvmCross sample here
I am trying to show an activity, that contains a fragment. When I call ShowViewModel on the Activity, I see the activity, without the contained fragment.
If I call ShowViewModel on the Fragment, the Activity AND the Fragment are created.
Does this mean, in order to show a fragment I need to call ShowViewModel on the fragment and not on the parent activity? surly I should be able to call ShowViewModel on the activity and have that create the fragment.
Sorry if i'm missing something here.
Thanks

Start loading url in fragment from othere fragment

I have two fragments in app. When user launch the app, in main layout fragment container shows first fragment, when user click on the button, second fragment replaces first fragment.
I want to do this: when app launch, in second fragment loading some text from the GET url request. And when user click on button to show seecond fragment, all text has already been loaded.
How can I do this ?
Maybe, make function "loadContent" in second fragment and when app launches call this function..
Is anybody have any ideas/info about this, please provide me^)

Make the GET call in Activity's onCreate method. Define your own interface which has an abstract getter. Implement the interface on Activity, and override the getter to return GET response.
In fragment onAttach(Activity) initialize interface like :
Interface callback = new Interface(activity);
now get the data, anywhere in fragment lifecycle after onAttach, from callback object like :
callback.getterFunction();

Android how to send data to a running fragment

is there a way to send some data from an activity to a running fragment?
In my app I'm adding a second fragment over another fragment. I intentionally use the add method instead of the replace method. So now I want to hide my second fragment with
fragmentManager.popBackStack();
and my first fragment reappears. After hiding the second fragment I want to send some data from my activity to the still running frist fragment.
Any idea how to do this? It doesn't work with bundles (put extra), because I don't rebuild the fragment, I just hide the second one!

one simple solution is:
MyFragment oldFragment = (MyFragment) fragmentManager.findFragmentById(R.id.fragment_place);
fragmentManager.popBackStackImmediate();
MyFragment newFragment = (MyFragment)fragmentManager.findFragmentById(R.id.fragment_place);
newFragment.postData(...);

You can use an EventBus library like this one, it's easy to use and very convenient.

You can use tags on the Fragments when you create them to call them when needed.
getFragmentManager().beginTransaction()
.add(R.id.content, new SomeFragment(), SomeFragment.class.getSimpleName())
.commit();
So above I use the simple name of the class to tag the fragment when I create and add it to the activity.
SomeFragment fragment = (SomeFragment) getFragmentManager().findFragmentByTag(SomeFragment.class.getSimpleName());
And I can call it back when I need it and know it is being displayed like above, now I can call send it data like normal by calling a public method in the custom fragment and passing it the data as a param.

How to update TextView in a fragment when exiting from another fragment?

So I have a fragment A which has a button to open another a fragment B. In fragment B I can pick some options, which is bundled into an Bundleobject. When I exit from fragment B, I want to refresh a TextView in fragment A.
Right now I'm using dismiss() method to remove the fragment, and then call back the fragment again so that onCreateView() is called. It works fine, but I don't want the animation where the fragment windows is run. So I like to not use dismiss() to remove the fragment instead I want to keep it on the Activity, but I need to know how I can refresh fragment A. I've tried overriding onActivityCreated() but it didn't result in the action I wanted.
So I wonder what's the approach if I want to refresh fragment A without having to dismiss it first so that onCreateView() can be called again.
I can attach code if needed. But maybe just an explanation is enough here?

you can use the life cycle function onResume() in fragment A to update the textview.

You can create your own Listener interface ( example how to do it or this) that listens when you remove your fragment, and you can get the event on Fragment A where you can setText to your TextView.

How to make call backs between Fragments of the same Ativity

I have 4 tabs in an Activity.
Each of them is a Fragment. And every Fragment has a ListView.
So, if i change the ListView in Fragment, it must change the ListView in all other Fragments ie.., Tabs.
The problem i face is while creating the interface instance.
It takes it's own onClick() method.
In case i want a callback to the parent activity i could have done that by overriding onAttach. But how to make a callback to a Fragment?
From Developers site:
Often you will want one Fragment to communicate with another, for example to change the content based on a user event. All Fragment-to-Fragment communication is done through the associated Activity. Two Fragments should never communicate directly.
So, make a callback to the Activity which in turn makes a callback to other fragments??
Thank You

It's pretty simple,all You need is steps below:
1) From onClick method in your first fragment make a function call of activity:
((IYourActivityInterface) getActivty()).activityMethod();
2) In your activity find fragment by tag or id and run it's method:
public void activityMethod(){
Fragment tabFragment = getFragmentManager().findFragmentByTag("second_fragment");
// or Fragment tabFragment = getFragmentManager().findFragmentById(R.id.frag);
if (tabFragment!=null){
((IFragmentInterface) tabFragment).fragmentMethod();
}
}
Hope this is what you are looking for.)