im trying to set background to my activity but it throws nullpointer exception everytime
here is my code
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
RelativeLayout layout = (RelativeLayout) findViewById(R.layout.activity_main);
layout.setBackground(getResources().getDrawable(R.drawable.welcome_2));
if(sdk < android.os.Build.VERSION_CODES.JELLY_BEAN) {
layout.setBackgroundDrawable( getResources().getDrawable(R.drawable.welcome_1) );
} else {
layout.setBackground(getResources().getDrawable(R.drawable.welcome));
}
setContentView(R.layout.activity_main);
and this is my layout
<RelativeLayout 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=".MainActivity" >
move
setContentView(R.layout.activity_main);
before
RelativeLayout layout = (RelativeLayout) findViewById(R.id.layout);
and defined relativelayout Id in XML
<RelativeLayout 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"
android:id="#+id/layout"
tools:context=".MainActivity" >
Firstly Give id to Layout in Xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:id="#+id/layout"
android:layout_height="match_parent"
tools:context=".MainActivity" >
Then Inside java Code Use like this
setContentView(R.layout.activity_main);
RelativeLayout layout = (RelativeLayout) findViewById(R.id.layout);
layout.setBackground(R.drawable.welcome_2);
Related
I've Activity with a custom titlebar loaded like this
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
final RelativeLayout frameLayout = new RelativeLayout(this);
setContentView(frameLayout);
getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE,
R.layout.lfpdftitlebar_v2);
View v = findViewById(R.id.pdftoolbar);
//v is Null only on some Android 7 devices
}
and the R.id.pdftoolbar
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/pdftoolbar"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#color/white"
android:orientation="vertical" >
<RelativeLayout
android:id="#+id/pdftoolbar_all"
android:layout_width="fill_parent"
android:layout_height="45dp"
android:background="#color/light_blue"
android:descendantFocusability="beforeDescendants"
android:elevation="5dp"
android:orientation="horizontal" >
</RelativeLayout>
</LinearLayout>
Only on some Android 7 devices I can't access View defined in layout R.layout.window_title because the this.findViewById or getWindow().findViewById() on this object return null
I am trying to add textviews dynamically to my activity and I am able to do so but the added textviews are getting added next to each other on the right side and what I want is to have each textview underneath each other.
Here is my code:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
LinearLayout linearLayout = (LinearLayout)findViewById(R.id.linearLayout);
for(int x = 0;x < 10; x++){
LinearLayout layout = new LinearLayout(this);
TextView tv = new TextView(this);
tv.setText("Text View "+x);
layout.setOrientation(LinearLayout.HORIZONTAL);
layout.addView(tv);
linearLayout.addView(layout);
}
}
Main XML:
<RelativeLayout 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" android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin" tools:context=".MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/linearLayout"
android:orientation="horizontal"></LinearLayout>
</RelativeLayout>
You can do this way:
You have to set orientation vertical of your parent Linear Layout:
Your xml should looks like this:
<RelativeLayout 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" android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin" tools:context=".MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/linearLayout"
android:orientation="vertical"></LinearLayout>
</RelativeLayout>
Your java code should looks like this:
for(int x = 0;x < 10; x++){
TextView tv = new TextView(this);
tv.setText("Text View "+x);
linearLayout.addView(tv);
}
Hope this will help you.
Instead of this:
layout.setOrientation(LinearLayout.HORIZONTAL);
Do this to your linear layout:
layout.setOrientation(LinearLayout.VERTICAL);
Why listView can't addHeaderView to itself?
I have added the params into the header rather than WRAP_CONTENT,MATCH_PARETN.
MainActivity:
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView list = (ListView) findViewById(R.id.lv);
LinearLayout head = (LinearLayout) getLayoutInflater().inflate(R.layout.layout, null);
AbsListView.LayoutParams params = new AbsListView.LayoutParams(
200,200
);
head.setLayoutParams(params);
list.addHeaderView(head);
}
}
activity_main.xml:
<RelativeLayout 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"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".MainActivity">
<ListView
android:id="#+id/lv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</RelativeLayout>
layout.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="#+id/iv"
android:layout_width="200dp"
android:layout_height="200dp"
android:src="#mipmap/ic_launcher" />
</LinearLayout>
What should i do?
Try to imprort LayoutParams from RelativeLayout class instead of AbsListView. I think it may be problem of Class casting.
I want to inflate a view with only an image to be above my main layout center screen, so far I only am able to add an inflated view as the first child of my main layout. How can I inflate an imageview to be above my other views and be in the center of the screen?
LayoutInflater inflater = (LayoutInflater)getApplicationContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
layout = inflater.inflate(R.layout.image_preview,(ViewGroup)findViewById(R.id.previewHolder));
((LinearLayout) (LinearLayout)findViewById(R.id.fullScreen)).addView(layout);//add inflated to main view
Main layout
<LinearLayout 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"
android:focusable="true"
android:orientation="vertical"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
>
<LinearLayout
android:id="#+id/fullScreen"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</LinearLayout>
<TableLayout
android:id="#+id/root"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:focusableInTouchMode="true"
android:stretchColumns="*" >
........................
</TableLayout>
</LinearLayout>
Activity
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_testing_cam);
badge.setOnClickListener(btnListener);
}
private OnClickListener btnListener = new OnClickListener() {
#Override
public void onClick(View v) {
//SELECTS BUTTON ACTIONS
switch(v.getId()){
case R.id.status:
finish();
break;
default:
previewImages(v.getId());
break;
}
}
};
//CARRY OUT IMAGE FUNCTIONS
public void previewImages(int index){
try{
LayoutInflater inflater = (LayoutInflater)getApplicationContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
layout = inflater.inflate(R.layout.image_preview,(ViewGroup)findViewById(R.id.previewHolder));
((LinearLayout) (LinearLayout)findViewById(R.id.fullScreen)).addView(layout);
ImageView iv = (ImageView)findViewById(R.id.previewImage);
BitmapDrawable drawable = (BitmapDrawable) ((ImageView) showCase.getChildAt(index)).getDrawable();
Bitmap bitmap = drawable.getBitmap();
iv.setImageBitmap(bitmap);
((LinearLayout) (LinearLayout)findViewById(R.id.fullScreen)).bringToFront();
}catch(Exception e){ Log.i("ERROR FLATE", e.toString()); }
return;
}
View being inflated
<?xml version="1.0" encoding="utf-8"?>
<ImageView
android:id="#+id/previewImage"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:adjustViewBounds="true"
android:scaleType="fitXY"/>
If you want to add the preview above fullScreen and root you should modify your parent layout.
LinearLayout arrange its children vertically, while in this case you need to use a FrameLayout or a RelativeLayoutinstead.
Something like this:
<RelativeLayout 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"
android:focusable="true">
<!-- your previous content -->
<LinearLayout 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"
android:orientation="vertical"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin">
<LinearLayout
android:id="#+id/fullScreen"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</LinearLayout>
<TableLayout
android:id="#+id/root"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:focusableInTouchMode="true"
android:stretchColumns="*" >
........................
</TableLayout>
</LinearLayout>
<!-- your preview -->
<ImageView
android:id="#+id/preview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:visibility="gone"/>
</RelativeLayout>
All you have to do on click is to change the visibility of preview ImageView to visible and set its source accordingly.
I've a layout activity_main.xml which contains this:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
</LinearLayout>
And I've a layout, new_bucket.xml which contains this code:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/newEntry"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
<LinearLayout
android:id="#+id/main"
android:layout_width="fill_parent"
android:layout_height="100dp"
android:background="#253514"
android:clickable="true"
android:onClick="toggleAmagar"
android:orientation="vertical" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="text1"
android:textColor="#ffffff" />
</LinearLayout>
<LinearLayout
android:id="#+id/child"
android:layout_width="fill_parent"
android:layout_height="150dp"
android:layout_below="#id/main"
android:background="#666666"
android:clickable="true"
android:onClick="toggleAmagar"
android:orientation="vertical">
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="text2" />
</LinearLayout>
</LinearLayout>
What I want to achieve, is to programatically add several "instances" of new_bucket.xml to the main layout in activity_main.xml. Those instances, should appear inside the LinearLayout of activity_main.xml.
I'm a bit stuck at the moment. I've tried to just add a TextView to activity_main.xml but I can't even handle that...
LinearLayout my_root = (LinearLayout) getLayoutInflater().inflate(R.layout.activity_main, null);
LinearLayout A = new LinearLayout(this);
A.setOrientation(LinearLayout.HORIZONTAL);
TextView tv = new TextView(this);
tv.setText("This text should appear somewhere");
A.addView(tv);
my_root.addView(A);
But that TextView is never shown.
Can you help me out?
You mean like this?
LinearLayout container = (LinearLayout)findViewById(R.id.container);
View child = getLayoutInflater().inflate(R.layout.new_bucket, container);
container.addView(child);
See documentation.
layout activity_main.xml
// i added an Id for LinearLayout
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
>
</LinearLayout>
This code will add your new_bucket to your main LinearLayout
LinearLayout my_root = (LinearLayout) findViewById(R.id.container, null);
LayoutInflater mInflater = (LayoutInflater) getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
View bucket= (View) mInflater.inflate(R.layout.new_bucket, null);
my_root.addView(bucket);
Hope this work for you.
LinearLayout container = (LinearLayout)findViewById(R.id.container);
View child = getLayoutInflater().inflate(R.layout.new_bucket, container, false);
child.setId(0);
container.addView(child);
if u want to inflate multiple layout use for loop for this.
After so many help from so nice guys, I managed to do that.
I have not changed any Layout from the main question.
BUT java code is like this now:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
LinearLayout my_root = (LinearLayout) findViewById(R.id.container);
LayoutInflater mInflater = (LayoutInflater) getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
View bucket= (View) mInflater.inflate(R.layout.new_bucket, null);
my_root.addView(bucket);
}