Changing gradient background colors on Android at runtime

Yes! Found a way!

Had to forget about XML, but here's how I did it:

On my getView() overloaded function (ListAdapter) I just had to:

    int h = v.getHeight();    ShapeDrawable mDrawable = new ShapeDrawable(new RectShape());    mDrawable.getPaint().setShader(new LinearGradient(0, 0, 0, h, Color.parseColor("#330000FF"), Color.parseColor("#110000FF"), Shader.TileMode.REPEAT));    v.setBackgroundDrawable(mDrawable);

And that gave me the same result as the XML background above. Now I can programmatically set the background color.

I tried using Phenome's solution for Button view. But somehow it did not work.

I came up with something else: (Courtesy: Android API Demo examples)

package com.example.testApp;import android.app.Activity;import android.graphics.drawable.GradientDrawable;import android.os.Bundle;import android.view.View;public class TetApp extends Activity {    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        View v = findViewById(R.id.btn);        v.setBackgroundDrawable( new DrawableGradient(new int[] { 0xff666666, 0xff111111, 0xffffffff }, 0).SetTransparency(10));    }    public class DrawableGradient extends GradientDrawable {        DrawableGradient(int[] colors, int cornerRadius) {            super(GradientDrawable.Orientation.TOP_BOTTOM, colors);            try {                this.setShape(GradientDrawable.RECTANGLE);                this.setGradientType(GradientDrawable.LINEAR_GRADIENT);                this.setCornerRadius(cornerRadius);            } catch (Exception e) {                e.printStackTrace();            }        }        public DrawableGradient SetTransparency(int transparencyPercent) {            this.setAlpha(255 - ((255 * transparencyPercent) / 100));            return this;        }    }}

Try my code below:

 int[] colors = new int[2];            colors[0] = getRandomColor();            colors[1] = getRandomColor();            GradientDrawable gd = new GradientDrawable(                    GradientDrawable.Orientation.TOP_BOTTOM, colors);            gd.setGradientType(GradientDrawable.RADIAL_GRADIENT);            gd.setGradientRadius(300f);            gd.setCornerRadius(0f);            YourView.setBackground(gd);

Method for generating random color:

public static int getRandomColor(){    Random rnd = new Random();    return Color.argb(255, rnd.nextInt(256), rnd.nextInt(56), rnd.nextInt(256));}