Solution 1:

This is the solution I figured out to handle this issue:

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    Dialog dialog = super.onCreateDialog(savedInstanceState);    
    dialog.getWindow().requestFeature(Window.FEATURE_NO_TITLE);

    return dialog;
}

@Override
public void onStart() {
    super.onStart();

    Dialog dialog = getDialog();
    if (dialog != null) {
       dialog.getWindow().setLayout(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
       dialog.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
    }
}

Edit:

You can use the code below in onCrateView method of Fragment before return the inflated view.

getDialog().getWindow().requestFeature(Window.FEATURE_NO_TITLE);
getDialog().getWindow().setBackgroundDrawable(new ColorDrawable(android.graphics.Color.TRANSPARENT));

Solution 2:

Have you tried using the answer of Elvis from How to make an alert dialog fill 90% of screen size?

It is the following:

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

Update:

Above code should be added inside onStart() method of the DialogFragment.

Solution 3:

This is worked for me

Create your custom style :

   <style name="DialogStyle" parent="Base.Theme.AppCompat.Dialog">
    <item name="android:windowMinWidthMajor">97%</item>
    <item name="android:windowMinWidthMinor">97%</item>
   </style>

You can also try use the right parent to match your other dialogs. for example parent="ThemeOverlay.AppCompat.Dialog" and so on.

Use this style in your dialog

public class MessageDialog extends DialogFragment {

@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setStyle(DialogFragment.STYLE_NO_TITLE, R.style.DialogStyle);
}

// your code 
}

Solution 4:

For me, it worked when I replaced the LinearLayout parent of the layout inflated in onCreateView by RelativeLayout. No other code change required.

Solution 5:

    <!-- A blank view to force the layout to be full-width -->
    <View
        android:layout_width="wrap_content"
        android:layout_height="1dp"
        android:layout_gravity="fill_horizontal" />

in the top of my dialog layout did the trick.