How to set background color of an Activity to white programmatically?
How can I se开发者_StackOverflowt the background color of an Activity to white programatically?
Add this single line in your activity, after setContentView()
call
getWindow().getDecorView().setBackgroundColor(Color.WHITE);
Get a handle to the root layout used, then set the background color on that. The root layout is whatever you called setContentView with.
setContentView(R.layout.main);
// Now get a handle to any View contained
// within the main layout you are using
View someView = findViewById(R.id.randomViewInMainLayout);
// Find the root view
View root = someView.getRootView();
// Set the color
root.setBackgroundColor(getResources().getColor(android.R.color.red));
I prefer coloring by theme
<style name="CustomTheme" parent="android:Theme.Light">
<item name="android:windowBackground">@color/custom_theme_color</item>
<item name="android:colorBackground">@color/custom_theme_color</item>
</style>
?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#FFFFFF"
android:id="@+id/myScreen"
</LinearLayout>
In other words, "android:background" is the tag in the XML you want to change.
If you need to dynamically update the background value, see the following:
Exercise: Change background color, by SeekBar
In your onCreate()
method:
getWindow().getDecorView().setBackgroundColor(getResources().getColor(R.color.main_activity_background_color));
Also you need to add to values folder a new XML file called color.xml
and Assign there a new color property:
color.xml:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="main_activity_background_color">#000000</color>
</resources>
Note that you can name the color.xml
any name you want but you refer to it by code as R.color.yourId
.
EDIT
Because getResources().getColor()
is deprecated, use getWindow().getDecorView().setBackgroundColor(ContextCompat.getColor(MainActivity.this, R.color.main_activity_background_color));
instead.
You can use this to call predefined android colours:
element.setBackgroundColor(android.R.color.red);
If you want to use one of your own custom colours, you can add your custom colour to strings.xml and then use the below to call it.
element.setBackgroundColor(R.color.mycolour);
However if you want to set the colour in your layout.xml you can modify and add the below to any element that accepts it.
android:background="#FFFFFF"
Button btn;
View root;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn = (Button)findViewById(R.id.button);
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
root =findViewById(R.id.activity_main).getRootView();
root.setBackgroundColor(Color.parseColor("#FFFFFF"));
}
});
}
To get the root view defined in your xml file, without action bar, you can use this:
View root = ((ViewGroup) findViewById(android.R.id.content)).getChildAt(0);
So, to change color to white:
root.setBackgroundResource(Color.WHITE);
View randview = new View(getBaseContext());
randview = (View)findViewById(R.id.container);
randview.setBackgroundColor(Color.BLUE);
worked for me. thank you.
final View rootView = findViewById(android.R.id.content);
rootView.setBackgroundResource(...);
for activity
findViewById(android.R.id.content).setBackgroundColor(color)
The best method right now is of course
getWindow().getDecorView().setBackgroundColor(ContextCompat.getColor(MainActivity.this, R.color.main_activity_background_color));
Please be aware though, if you have anything set as the background color in Designer, it will overwrite anything you try to set in your code.
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