add
android:layout_gravity="center_vertical"
to both your ImageView and your Button, that will give you the alignment you depicted in your image.
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:weightSum="100" >
<ImageView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_weight="80"
android:gravity="right"
android:src="https://stackoverflow.com/questions/25706451/@drawable/image" />
<Button
android:id="@+id/blah"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_weight="20"
android:gravity="left"
android:text="Blah blah blah blah"
android:textSize="15sp" />
</LinearLayout>
Also you didn’t set the height for your button.
0
solved I’m making weightSum but it can’t be sorted