在这个例程中主要讲述了ShapeDrawable,以及各种Gradient
首先初始化了 mDrawables = new ShapeDrawable[7];默认的是矩形,
当然还有其他形状:
 mDrawables[0] = new ShapeDrawable(new RectShape());
 mDrawables[1] = new ShapeDrawable(new OvalShape());
 mDrawables[4] = new ShapeDrawable(new RoundRectShape(outerR, inset,
 innerR));
 mDrawables[5] = new ShapeDrawable(new PathShape(path, 100, 100));
float[] outerR = new float[] { 12, 12, 12, 12, 0, 0, 0, 0 };
 RectF inset = new RectF(20, 20, 20, 20);
 float[] innerR = new float[] { 12, 12, 0, 0, 12, 12, 0, 0 };
 Path path = new Path();
 path.moveTo(50, 0);
 path.lineTo(0, 50);
 path.lineTo(50, 100);
 path.lineTo(100, 50);
 path.close();
实例化ShapeDrawable后就可以对他们进行设置:
设置渐变
mDrawables[0].getPaint().setShader(makeTiling());
设置颜色
 mDrawables[1].getPaint().setColor(0xFF00FF00);
设置影响 影响呢有很多 可以设置单个 也可以用组合
PathEffect pe = new DiscretePathEffect(10, 2);
 PathEffect pe2 = new CornerPathEffect(8);
 mDrawables[3].getPaint().setPathEffect(
 new SumPathEffect(pe2, pe));
其中渐变又包括:
 private static Shader makeSweep() {
 return new SweepGradient(150, 25, new int[] { 0xFFFF0000, 0xFF00FF00, 0xFF0000FF, 0xFFFF0000 }, null);
 //return new SweepGradient(150, 25, new int[] { 0xFFFF0000, 0xFF00FF00, 0xFF0000FF }, new float[]{0.9f,0.1f,0.9f});
 }
 private static Shader makeLinear() {
 return new LinearGradient(0, 0, 50, 50,
 new int[] { 0xFFFF0000, 0xFF00FF00, 0xFF0000FF },
 null, Shader.TileMode.REPEAT);
 }
 private Shader makeTiling() {
 int[] pixels = new int[] { 0xFFFF0000, 0xFF00FF00, 0xFF0000FF, 0};
 Bitmap bm = Bitmap.createBitmap(pixels, 2, 2, Bitmap.Config.ARGB_8888);
 // Bitmap bm = Bitmap.createBitmap(mBitmap, 60, 45, Bitmap.Config.ARGB_8888);
 return new BitmapShader(bm, Shader.TileMode.REPEAT,
 Shader.TileMode.REPEAT);
 }
最后在这个实例中 可以自定义一个ShapeDrawable
private static class MyShapeDrawable extends ShapeDrawable {
 private Paint mStrokePaint = new Paint(Paint.LINEAR_TEXT_FLAG);
 public MyShapeDrawable(Shape s) {
 super(s);
 mStrokePaint.setStyle(Paint.Style.STROKE);
 mStrokePaint.setColor(Color.GREEN);
 }
 public Paint getStrokePaint() {
 return mStrokePaint;
 }
 @Override protected void onDraw(Shape s, Canvas c, Paint p) {
//第一个调用父类的p,第二个调用自己刚才设置的p,如果你不想使用默认的父类,默认的颜色为黑了 
 s.draw(c, p);
 s.draw(c, mStrokePaint);
 }
 mDrawables[6] = new MyShapeDrawable(new ArcShape(45, 360));
 MyShapeDrawable msd = (MyShapeDrawable)mDrawables[6];
 msd.getStrokePaint().setStrokeWidth(1);
 }