适用于各种屏幕尺寸的Android ImageButton

Question

I am trying to create an image button which will cater for a variety of screens. However, I cannot get the image button to correctly fit a larger screen and instead shows a much smaller image on the image button.

What I have tried so far:

• I have used this link to generate nine-patch images, however even if i add the files to the drawable: ldpi, mdpi, ldpi, xhdpi and xxhdpi folders, the image is still shorter than the screen width
• I have tried using android:scaleType="fitXY" and android:adjustViewBounds="true" . This does adjust to each screen size but you can see the edges of the grey Image Button clickable area around the outskirts of the image.

Is there anything wrong with my layout file below or is there certain image dimensions which are required?

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >

<ScrollView
    android:id="@+id/homepageScrollView1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_alignParentLeft="true"
    android:layout_alignParentRight="true"
    android:layout_alignParentTop="true" >

    <RelativeLayout
        android:id="@+id/homepageRelLayout2"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="fill" >

    <ImageButton
        android:id="@+id/homepageImageButton"
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:layout_alignParentLeft="true"
        android:layout_marginTop="40dp"
        android:src="@drawable/someImage" />

    </RelativeLayout>

</ScrollView>

</RelativeLayout>

Answer 1

If you use ImageView + click listener, you will lose the button in/out effect. Maybe you can try to give your ImageButton a transparent background like this:

android:background="?android:selectableItemBackground"

Don't use @null or @android:color/transparent , they will lose the button effect as well.

Btw, android:selectableItemBackground doesn't work for old android version like 2.x