ImageView fills parent's width OR height, but maintains aspect ratio

These:

android:layout_height="wrap_content"
android:scaleType="fitStart"
android:adjustViewBounds="true"

should resize the image and change the size of the bounds to fit the new image size. If it does not do that on your device post the image you are using and what device you are testing on.

Use this code : android:scaleType="fitXY"

For more details about image scaling, look what's motioned in this article here

Summary:

• center

Center the image in the view, but perform no scaling

• centerCrop

Scale the image uniformly (maintain the image's aspect ratio) so that both dimensions (width and height) of the image will be equal to or larger than the corresponding dimension of the view (minus padding). The image is then centered in the view

• centerInside

Scale the image uniformly (maintain the image's aspect ratio) so that both dimensions (width and height) of the image will be equal to or less than the corresponding dimension of the view (minus padding)

• fitCenter

• fitEnd

• fitStart

• fitXY

• matrix

Scale using the image matrix when drawing

more details here new article

This xml code will work!. If you are specifying that your apps width is always same as the window, then the android:adjustViewBounds="true" will set the height respective to the ration of the image.

        <ImageView
        android:adjustViewBounds="true"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:src="@drawable/screen"/>

Use this code with view layout parameters as wrapcontent

android:adjustViewBounds="true"

Hope this it will work.

I had the same issue, android:adjustViewBounds not doing its job and having a padding at the top of the image. Into a relative layout that had match_parent values for the width and the height, I had:

   <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:orientation="vertical" android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:background="@color/transparent">

   <ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:scaleType="fitStart"
    android:adjustViewBounds="true" ...

I changed the Relative layout to a Linear layout with wrap_content values for width and height and now it is ok:

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"