I need to create an alpha-gradient on the edge of the ImageView. Preferably using only XML.
Here the solution
the image look like below picture
code for that:
- Prepare shape drawable
res/drawable/gradient_shape.xml:
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<gradient
android:startColor="#00FFFFFF"
android:endColor="#FFFFFFFF"
android:type="linear" />
</shape>
Define layout: activity_main.xml:
<ImageView
android:id="@+id/photo"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/photo"
android:src="@drawable/gradient_shape" />
here drawable/photo is just jpeg in drawables folder
EDIT for more information refer this Tutorial
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<gradient
android:startColor="#00FFFFFF"
android:endColor="#FFFFFFFF"
android:type="linear" />
</shape>
perfect transperancy. Make sure that the View below gradient is actually below and not just touching Gradient shape View.
If you have main RelativeLayout, ListView and View(Background:Gradient )
make sure that Gradient View is on top, of the ListView, and not a side. If Your gradient is aside it will be transparent by RelativeLayout Background Color and not by ListView .
i hope you understand what i want to say.
For transparency :
android:startColor="@null"
Or you can use a 8-digit hex color like that :
android:startColor="#FF000000"
The first two FF are for the alpha of the color, 00 is fully transparent and FF opaque
来源:https://stackoverflow.com/questions/14345824/alpha-gradient-on-android