I am having trouble applying a gradient background to a LinearLayout.
This should be relatively simple from what I have read but it just doesn't seem to work. For reference sakes I am developing on 2.1-update1.
header_bg.xml:
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<gradient
android:angle="90"
android:startColor="#FFFF0000"
android:endColor="#FF00FF00"
android:type="linear"/>
</shape>
main_header.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="50dip"
android:orientation="horizontal"
android:background="@drawable/header_bg">
</LinearLayout>
If I change @drawable/header_bg to a color - e.g. #FF0000 it works perfectly fine. Am I missing something obvious here?
This question is related to
android
android-layout
android-linearlayout
gradient
<?xml version="1.0" encoding="utf-8"?>
<gradient
android:angle="90"
android:startColor="@color/colorPrimary"
android:endColor="@color/colorPrimary"
android:centerColor="@color/white"
android:type="linear"/>
<corners android:bottomRightRadius="10dp"
android:bottomLeftRadius="10dp"
android:topRightRadius="10dp"
android:topLeftRadius="10dp"/>
In XML Drawable File:
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<shape>
<gradient android:angle="90"
android:endColor="#9b0493"
android:startColor="#38068f"
android:type="linear" />
</shape>
</item>
</selector>
In your layout file: android:background="@drawable/gradient_background"
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/gradient_background"
android:orientation="vertical"
android:padding="20dp">
.....
</LinearLayout>
Change color values in the array
val gradientDrawable = GradientDrawable(
GradientDrawable.Orientation.TOP_BOTTOM,
intArrayOf(Color.parseColor("#008000"),
Color.parseColor("#ADFF2F"))
);
gradientDrawable.cornerRadius = 0f;
//Set Gradient
linearLayout.setBackground(gradientDrawable);
Result
It is also possible to have the third color (center). And different kinds of shapes.
For example in drawable/gradient.xml:
<shape
xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<gradient
android:startColor="#000000"
android:centerColor="#5b5b5b"
android:endColor="#000000"
android:angle="0" />
</shape>
This gives you black - gray - black (left to right) which is my favorite dark background atm.
Remember to add gradient.xml as background in your layout xml:
android:background="@drawable/gradient"
It is also possible to rotate, with:
angle="0"
gives you a vertical line
and with
angle="90"
gives you a horizontal line
Possible angles are:
0, 90, 180, 270.
Also there are few different kind of shapes:
android:shape="rectangle"
Rounded shape:
android:shape="oval"
and problably a few more.
Hope it helps, cheers!
My problem was the .xml extension was not added to the filename of the newly created XML file. Adding the .xml extension fixed my problem.
Try removing android:gradientRadius="90". Here is one that works for me:
<shape
xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle"
>
<gradient
android:startColor="@color/purple"
android:endColor="@color/pink"
android:angle="270" />
</shape>
I would check your alpha channel on your gradient colors. For me, when I was testing my code out I had the alpha channel set wrong on the colors and it did not work for me. Once I got the alpha channel set it all worked!
You can used a custom view to do that. With this solution, it's finished the gradient shapes of all colors in your projects:
class GradientView(context: Context, attrs: AttributeSet) : View(context, attrs) {
// Properties
private val paint: Paint = Paint()
private val rect = Rect()
//region Attributes
var start: Int = Color.WHITE
var end: Int = Color.WHITE
//endregion
override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
super.onSizeChanged(w, h, oldw, oldh)
// Update Size
val usableWidth = width - (paddingLeft + paddingRight)
val usableHeight = height - (paddingTop + paddingBottom)
rect.right = usableWidth
rect.bottom = usableHeight
// Update Color
paint.shader = LinearGradient(0f, 0f, width.toFloat(), 0f,
start, end, Shader.TileMode.CLAMP)
// ReDraw
invalidate()
}
override fun onDraw(canvas: Canvas) {
super.onDraw(canvas)
canvas.drawRect(rect, paint)
}
}
I also create an open source project GradientView with this custom view:
https://github.com/lopspower/GradientView
implementation 'com.mikhaellopez:gradientview:1.1.0'
I don't know if this will help anybody, but my problem was I was trying to set the gradient to the "src" property of an ImageView like so:
<ImageView
android:id="@+id/imgToast"
android:layout_width="wrap_content"
android:layout_height="60dp"
android:src="@drawable/toast_bg"
android:adjustViewBounds="true"
android:scaleType="fitXY"/>
Not 100% sure why that didn't work, but now I changed it and put the drawable in the "background" property of the ImageView's parent, which is a RelativeLayout in my case, like so: (this worked successfully)
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:id="@+id/custom_toast_layout_id"
android:layout_height="match_parent"
android:background="@drawable/toast_bg">
Source: Stackoverflow.com