How to set dialog to show in full screen?

I have a GridView and i want to make an implémentation of a dialog, on which the picture that i have selected should display in full screen.

so how can i make the dialog shows in a full screen mode ? thanks!

try

Dialog dialog=new Dialog(this,android.R.style.Theme_Black_NoTitleBar_Fullscreen)

based on this link , the correct answer (which i've tested myself) is:

put this code in the constructor or the onCreate() method of the dialog:

getWindow().setLayout(WindowManager.LayoutParams.MATCH_PARENT,
				WindowManager.LayoutParams.MATCH_PARENT);

in addition , set the style of the dialog to :

<style name="full_screen_dialog">
	<item name="android:windowFrame">@null</item>
	<item name="android:windowIsFloating">true</item>
	<item name="android:windowContentOverlay">@null</item>
	<item name="android:windowAnimationStyle">@android:style/Animation.Dialog</item>
	<item name="android:windowSoftInputMode">stateUnspecified|adjustPan</item>
</style>

this could be achieved via the constructor , for example :

public FullScreenDialog(Context context)
{
  super(context, R.style.full_screen_dialog);
  ...

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EDIT: an alternative to all of the above would be to set the style to android.R.style.ThemeOverlay and that's it.

EDIT2: To support material library, add Gradle dependency to app(module) build.gradle file

implementation "com.google.android.material:material:$material_version"

Then set dialog's theme to R.style.ThemeOverlay_MaterialComponents

The easiest way I found

Dialog dialog=new Dialog(this,android.R.style.Theme_Black_NoTitleBar_Fullscreen);
        dialog.setContentView(R.layout.frame_help);
        dialog.show();

EDIT Until such time as StackOverflow allows us to version our answers, this is an answer that works for Android 3 and below. Please don't downvote it because it's not working for you now, because it definitely works with older Android versions.

---

You should only need to add one line to your onCreateDialog() method:

@Override
protected Dialog onCreateDialog(int id) {
	//all other dialog stuff (which dialog to display)

	//this line is what you need:
	dialog.getWindow().setFlags(LayoutParams.FLAG_FULLSCREEN, LayoutParams.FLAG_FULLSCREEN);

	return dialog;
}

dialog = new Dialog(getActivity(),android.R.style.Theme_Translucent_NoTitleBar);
	dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
	dialog.setContentView(R.layout.loading_screen);
	Window window = dialog.getWindow();
	WindowManager.LayoutParams wlp = window.getAttributes();

	wlp.gravity = Gravity.CENTER;
	wlp.flags &= ~WindowManager.LayoutParams.FLAG_BLUR_BEHIND;
	window.setAttributes(wlp);
	dialog.getWindow().setLayout(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
	dialog.show();

try this.