I am new to Android dev and am having trouble formatting some buttons.

<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_margin="0dp"
android:padding="0dp">
<Button
android:id="@+id/char_str_plus"
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_margin="0dp"
android:padding="0dp"
android:text="+"
android:textSize="16sp" />
<Button
android:id="@+id/char_str_min"
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_margin="0dp"
android:padding="0dp"
android:text="-"
android:textSize="16sp" />
As you can see from the pic the button does not fill the blue square. I’m not sure why. Appreciate any help.
Not sure if this will work, but you can try this:
Thats what I use on imagebuttons.