Develop Reference

Android Xamarin - FindViewById returns all except the top LinearLayout

Using Xamarin.Android native in Visual Studio 2017.
Here is an example of my layout. Let's call it 'headache.axml'.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/topLinearLayoutId"
android:paddingLeft="20dp"
android:paddingTop="0dp"
android:paddingRight="20dp"
android:paddingBottom="15dp"
android:layout_height="0dp"
android:layout_weight="1"
android:layout_width="match_parent"
android:onClick="showPasswordDialog"
android:orientation="horizontal" >
<TextView android:id="#+id/sampleId_0"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<TextView android:id="#+id/sampleId_1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
. . . more views . . .
</LinearLayout>
And here is the code where I inflate this layout.
View view = inflater.Inflate(Resource.Layout.fragment_selection, container, false);
ViewStub stub = (ViewStub) view.FindViewById(stubIds[i]);
stub.LayoutResource = Resource.Layout.headache;
View inflatedView = stub.Inflate();
Then I can use inflatedView.FindViewById() to get any view from my layout except the top LinearLayout.
For example, these lines work perfect:
var txtView0 = (TextView) inflatedView.FindViewById(Resource.Id.sampleId_0);
var txtView1 = (TextView) inflatedView.FindViewById(Resource.Id.sampleId_1);
Both txtView0 and txtView1 are initialized.
And here is my problem, when I try to get the top View from my layout I get null:
var top = (LinearLayout) inflatedView.FindViewById(Resource.Id.topLinearLayoutId); // returns null
As a workaround,
I've added a pre-top LinearLayout to my 'headache.axml'. It's become like this:
<?xml version="1.0" encoding="utf-8"?>
<!-- workaround: pre-top LinearLayout (still inaccessible) -->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/glitchyLinearLayout"
android:layout_height="match_parent"
android:layout_width="match_parent"
android:orientation="horizontal">
<!-- workaround: accessible LinearLayout -->
<LinearLayout
android:id="#+id/topLinearLayoutId"
android:paddingLeft="20dp"
android:paddingTop="0dp"
android:paddingRight="20dp"
android:paddingBottom="15dp"
android:layout_height="0dp"
android:layout_weight="1"
android:layout_width="match_parent"
android:orientation="vertical">
<TextView android:id="#+id/sampleId_0"
... all the same ... />
<TextView android:id="#+id/sampleId_1"
... all the same ... />
. . . more views . . .
</LinearLayout>
Now I can get my topLinearLayoutId.
var top = (LinearLayout) inflatedView.FindViewById(Resource.Id.topLinearLayoutId);
In this case, the top is initialized and my application works well.
But I'd like to understand why the hell I've got this problem.

Adding buttons below GraphView, all inside a Fragment

I have been trying to add Button's below a GraphView, and all these elements are part of a Fragment. Tried many approaches but none of them worked properly.
This is the layout file for the Fragment (fragment_graph.xml).
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.nma.util.sdcardtrac.GraphFragment">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/graph_fragment_layout"
android:orientation="vertical"
/>
</FrameLayout>
And this is the Java code dynamically adding a graph and button, placed in the Fragment's onViewCreated (View view, Bundle savedInstanceState).
storageGraph = new LineGraphView(getActivity(), graphLabel);
storageGraph.addSeries(graphSeries); // More config calls follow
...
LinearLayout view = (LinearLayout)getView().findViewById(R.id.graph_fragment_layout);
Button button = new Button(getActivity());
button.setText("Test");
view.addView(storageGraph);
view.addView(button);
The Button is not visible though I have set orientation to vertical for the LinearLayout containing it.
EDIT - solved!
I found that nesting the graph under its own LinearLayout and the buttons under another LinearLayout, and both of these wrapped in a LinearLayout fixed the problem! The LinearLayout containing the graph must be weighted (I chose a weight of 0.8).
Layout file looks like:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.nma.util.sdcardtrac.GraphFragment">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/graph_fragment_wrap"
android:orientation="vertical"
>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="0.8"
android:id="#+id/graph_fragment_layout"
android:orientation="vertical" />
<LinearLayout
android:id="#+id/graph_buttons"
android:orientation="horizontal"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_gravity="center_horizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:src="#drawable/ic_navigation_previous_item"/>
<ImageButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/ic_navigation_next_item"/>
</LinearLayout>
</LinearLayout>
</FrameLayout>

I've just tried it and it works. Perhaps your graph is taking all the available space, so added button is below the screen? Try to wrap your LinearLayout into a ScrollView and see if there is a button in the bottom.

How can we hide include layout programmatically in Android?

I have to include one layout in my application. So that I have used
<include
android:id="#+id/support_layout"
android:width="match_parent"
android:height="match_parent"
layout="#layout/support"/>
I have referenced this include tag in my java file using View.
View v = (View) findViewById(R.id.support_layout);
But at some point of my code I have to Hide this layout.
so that I used v.GONE
But it's not Hiding.
I want to reference those text and button attributes located in XML programatically.
How can I do that?
There is my support.xml:
<LinearLayout
android:id="#+id/support_layout"
android:width="match_parent"
android:height="match_parent">
<TextView
android:id="#+id/txt"
android:width="match_parent"
android:height="wrap_content"/>
<Button
android:id="#+id/btn"
android:width="match_parent"
android:height="wrap_content"
android:text="Button"/>
</LinearLayout>

Since <include/> is not a View type in android and visibility is the property of View, we can not access the visibility from included layout's reference.
However if you are using kotlin with view binding, we can get the reference of root of the included layout like binding.supportLayout.root which probably will be one of the View (ConstraintLayout, RelativeLayout, LinearLayout etc.)
Now we have reference of view means we can play with their visibility like below code.
binding.supportLayout.root.visibility = View.GONE
Hope you got the idea.

We need to see your actual implementation of hiding that View you mentioned.
But, straight from reading of your question, I presume that you've might do it the wrong way.
To hide or make a view invisible, use this:
yourView.setVisibility(View.INVISIBLE);
Bear in mind that this does not remove the view compeletly; it would still remain in your layout and you could get a reference to it or even try to manipulate it.
To remove it compeletly, use this instead:
yourView.setVisibility(View.GONE);
Now if you call this, yourView would be compeletly removed from the layout. You will no longer able to get a reference to it.

Put that view into a linearlayout and hide the linearlayout. It will work.
<LinearLayout
android:id="#+id/support_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<include
layout="#layout/support"
android:height="match_parent"
android:width="match_parent" /> </LinearLayout>
And don't forget writing Linearlayout instead of View.
Briefly, instead of
View v = (View) findViewById(R.id.support_layout);
Do this
LinearLayout v = (LinearLayout) findViewById(R.id.support_layout);

You can hide this "included" layout with calling setVisibility() :
v.setVisibility(View.GONE)
and show it later with calling :
v.setVisibility(View.VISIBLE)
To reference button and textview from support layout you can use findViewById method on your included View (I'm not sure but I think it's even not mandatory, you can call it directly on your activity's view) :
View supportLayout = (View) findViewById(R.id.support_layout);
Textview txv = (TextView) findViewById(R.id.txt);
Button btn = (Button) findViewById(R.id.btn);
(if it's not working try with : Button btn = (Button) supportLayout.findViewById(R.id.btn);)
-- FYI --
When you give attributs to include tags it override ones of the included layout (there support_layout LinearLayout) so you don't need to do that

you must use like this includedLayoutId.viewId.visibility = View.GONE in this case you can access to included view, now for example:
loading.xml
<com.airbnb.lottie.LottieAnimationView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/loading"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:lottie_autoPlay="true"
app:lottie_fileName="loading.json"
app:lottie_loop="true" />
in fragment_a.xml :
<include layout="#layout/loading"
android:id="#+id/anim_loading"
android:layout_width="match_parent"
android:layout_height="#dimen/_80sdp"/>
and finally use it animLoading.loading.visibility = View.GONE

Thanks to the new ConstraintLayout.
This is how I do it with widget.Group
<include
android:id="#+id/bottom_bar_action"
layout="#layout/bottom_bar_back_action"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent" />
<androidx.constraintlayout.widget.Group
android:id="#+id/bottom_bar_group"
android:layout_width="0dp"
android:layout_height="0dp"
app:constraint_referenced_ids="bottom_bar_action" />
Then you can hide the include layout by doing binding.bottomBarGroup.visibility = View.GONE. Cheers

// 1 - copy this
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".Add">
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="gone"
android:onClick="onclick_gone_include"/>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="visible"
android:onClick="onclick_visible_include"/>
<LinearLayout
android:id="#+id/support_layout"
android:gravity="center"
android:layout_width="match_parent"
android:layout_height="100dp"
>
<include
layout="#layout/support"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
</LinearLayout>
//code
//2 copy this to Add cliass
//this methods on click in Add class
public void onclick_gone_include(View view) {
View v = (View) findViewById(R.id.support_layout);//view is the v
v.setVisibility(View.GONE);
}
public void onclick_visible_include(View view) {
View v = (View) findViewById(R.id.support_layout);
v.setVisibility(View.VISIBLE);
}
//3 activity that included 'support activity'
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
tools:context=".Add"
android:gravity="center"
android:layout_height="wrap_content">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="textview1"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="textview2"
/>
</LinearLayout>

Android List Below Toggle Buttons

I have a list that is intended to be below toggle buttons. The list grabs data from a server and then parses them. My XML is as follows:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<ToggleButton
android:id="#+id/toggle_button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:textOff="Apps"
android:textOn="Apps" />
<ToggleButton
android:id="#+id/toggle_button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="#id/toggle_button1"
android:layout_weight="1"
android:textOff="VMs"
android:textOn="VMs" />
<ToggleButton
android:id="#+id/toggle_button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="#id/toggle_button2"
android:layout_weight="1"
android:textOff="Groups"
android:textOn="Groups" />
<ListView
android:id="#+id/mylist"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#id/toggle_button1" />
</RelativeLayout>
Code for the actual fragment:
public class ProblemFragment extends SherlockListFragment
{
private SeparatedListAdapter list;
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
this.getSherlockActivity().setContentView(R.layout.problem_layout);
list = new SeparatedListAdapter(this.getSherlockActivity(), new Layout(R.layout.separated_list_adapter_two_text, R.id.two_text_title, R.id.two_text_desc));
ToggleButton b1 = (ToggleButton) this.getSherlockActivity().findViewById(R.id.toggle_button1);
ToggleButton b2 = (ToggleButton) this.getSherlockActivity().findViewById(R.id.toggle_button2);
ToggleButton b3 = (ToggleButton) this.getSherlockActivity().findViewById(R.id.toggle_button3);
setListAdapter(list);
refresh();
}
public void refresh()
{
list = new SeparatedListAdapter(this.getSherlockActivity(), new Layout(R.layout.separated_list_adapter_two_text, R.id.two_text_title, R.id.two_text_desc));
refreshStats();
}
public void refreshStats()
{
//Omitted parsing code
list.addSection(new String("Hello world!!"));
setListAdapter(list);
}
}
However, when I use setListAdapter(list), the buttons are overwritten. They are visible before the app retrieves the data and parses it, but they are overwritten after I call setListAdapter. How can i fix this?

First, remove
android:orientation="horizontal"
from your root layout. RelativeLayout doesn't have an orientation property. Also, weight is for child elements of a LinearLayout and when you use it then you should assign the width of each child view to 0dp for horizontal orientation and height="0dp" for vertical orientation.
Then wrap your ToggleButtons in a LinearLayout, vertical or horizontal orientation, and give it the property
android:layout_alignParentTop="true"
then give your ListView the property
android:layout_below="#id/idOfLinearLayout"
So it may look something like
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<LinearLayout
android:id="#+id/toggleLL"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true">
<ToggleButton
android:id="#+id/toggle_button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textOff="Apps"
android:textOn="Apps" />
<ToggleButton
android:id="#+id/toggle_button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textOff="VMs"
android:textOn="VMs" />
<ToggleButton
android:id="#+id/toggle_button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textOff="Groups"
android:textOn="Groups" />
</LinearLayout>
<ListView
android:id="#+id/mylist"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#id/toggleLL" />
</RelativeLayout>
I also removed the RelativeLayout properties from the ToggleButtons since they are now wrapped in a LinearLayout. And you had a circular view error there with assigning the second ToggleButton to the right of itself which may have been a copy/paste error. Hope this helps.
Note that the default orientation for a LinearLayout is horizontal so leaving that property out will give you that effect.

Oh! I can not test your XML but I think that you need scrollbars! If the list is filled with a lot of entries, it can became bigger that the screen, making the buttons disappear because they are pushed up by the list. Try to add a scroll to the whole layout.
Something like this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<ScrollView
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<!-- Original layout here -->
</ScrollView>
</LinearLayout>
Of course, if you just put only one layout inside the scrollview, there is no need for the outer layout:
<?xml version="1.0" encoding="utf-8"?>
<ScrollView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
xmlns:android="http://schemas.android.com/apk/res/android">
<!-- Original layout here -->
</ScrollView>

RelativeLayout and ViewStub inflation

I have the following layout.
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content"
style="#style/list_item_bottom">
<TextView android:id="#+id/list_item_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<ViewStub android:id="#+id/stub_for_alt_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/list_item_name"
android:layout="#layout/text_view_alt_name"/>
<ImageView android:id="#+id/list_item_dopinfo1_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/stub_for_alt_name"
android:src="#drawable/ic_released"/>
</RelativeLayout>
I want ViewStub to be below TextView and ImageView to be below ViewStub.
Elements with ViewStub inflated are shown as I expect.
But elements without ViewStub have TextView overlapped with ImageView.
What's wrong with my layout?
UPDATE:
The only solution I've found is to give ViewStub and related TextView the same android:id value.

I know it's a bit of an old question but the trick in there is to set the inflatedId parameter to the same as the actual viewStub itself, like this:
<ViewStub android:id="#+id/stub_for_alt_name"
android:inflatedId="#id/stub_for_alt_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/list_item_name"
android:layout="#layout/text_view_alt_name"/>

The only solution I've found is to give ViewStub and related TextView the same android:id value.

It's an old question, but I've got a useful addition
1) Yes, like others have posted - use same id and inflatedId:
<ViewStub
android:id="#+id/view_stub_id"
android:inflatedId="#id/view_stub_id"
...
/>
2) When you need to inflate view or refresh its content it's convenient to act like this:
View v = parentView.findViewById(R.id.view_stub_id);
if (v instanceof ViewStub)
v = ((ViewStub) v).inflate();
// here v is always the inflated view
// ...

Hi you can try this one.
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content"
style="#style/list_item_bottom">
//you can add another relative layout containing your textview and imageview
<RelativeLayout
android:id="#+id/layout_content"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<TextView android:id="#+id/list_item_name"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<ImageView android:id="#+id/list_item_dopinfo1_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/stub_for_alt_name"
android:src="#drawable/ic_released"
android:layout_below="#+id/list_item_name" />
</RelativeLayout>
<ViewStub android:id="#+id/stub_for_alt_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/list_item_name"
android:layout="#layout/text_view_alt_name"
android:layout_below="#+id/layout_content" />
</RelativeLayout>