渲染器 Shader BitmapShader

渲染模式：tileX tileY：The tiling mode for x/y to draw the bitmap in. 在位图上 X/Y 方向 瓦工/花砖/瓷砖 模式 CLAMP ：如果渲染器超出原始边界范围，会复制范围内【边缘】染色REPEA ：横向和纵向的【重复】渲染器图片，平铺MIRROR：横向和纵向的重复渲染器图片，这个和REPEAT 重复方式不一样，他是以【镜像】方式平铺

public class LinearGradientView extends View {
private Paint mPaint = null;    private Shader mLinearGradient11 = null;    private Shader mLinearGradient12 = null;    private Shader mLinearGradient13 = null;    private Shader mLinearGradient21 = null;    private Shader mLinearGradient22 = null;    private Shader mLinearGradient23 = null;    private Shader mLinearGradient31 = null;    private Shader mLinearGradient32 = null;    private Shader mLinearGradient33 = null;    public LinearGradientView(Context context) {        super(context);        // 第一第二个参数表示渐变起点，可以设置在对角等任意位置；第三第四个参数表示渐变终点；第五个参数表示渐变颜色；        // 第六个参数可以为空，表示坐标值为0-1 new float[] {0.25f, 0.5f, 0.75f, 1 }  如果为空，颜色均匀分布，沿梯度线。          mLinearGradient11 = new LinearGradient(0, 0, 0, 200, new int[] { Color.RED, Color.GREEN, Color.BLUE, Color.BLACK }, null, TileMode.CLAMP);        mLinearGradient12 = new LinearGradient(0, 0, 0, 300, new int[] { Color.RED, Color.GREEN, Color.BLUE, Color.BLACK }, new float[] { 0, 0.1f, 0.5f, 0.5f }, TileMode.CLAMP);        mLinearGradient13 = new LinearGradient(0, 0, 0, 400, new int[] { Color.RED, Color.GREEN, Color.BLUE }, null, TileMode.CLAMP);        mLinearGradient21 = new LinearGradient(0, 320, 0, 320 + 200, new int[] { Color.RED, Color.GREEN, Color.BLUE, Color.BLACK }, null, TileMode.MIRROR);        mLinearGradient22 = new LinearGradient(0, 320, 0, 320 + 100, new int[] { Color.RED, Color.GREEN, Color.BLUE }, null, TileMode.MIRROR);        mLinearGradient23 = new LinearGradient(0, 320, 0, 320 + 100, new int[] { Color.RED, Color.GREEN, Color.BLUE }, new float[] { 0, 0.1f, 0.5f }, TileMode.MIRROR);        mLinearGradient31 = new LinearGradient(0, 640, 0, 640 + 200, new int[] { Color.RED, Color.GREEN, Color.BLUE, Color.BLACK }, null, TileMode.REPEAT);        mLinearGradient32 = new LinearGradient(0, 640, 0, 640 + 100, new int[] { Color.RED, Color.GREEN, Color.BLUE }, null, TileMode.REPEAT);        mLinearGradient33 = new LinearGradient(0, 640, 0, 640 + 100, new int[] { Color.RED, Color.GREEN, Color.BLUE }, new float[] { 0, 0.1f, 0.5f }, TileMode.REPEAT);        mPaint = new Paint();    }    @Override    protected void onDraw(Canvas canvas) {        //重复最后一个像素        mPaint.setStrokeWidth(2);        mPaint.setShader(mLinearGradient11);        canvas.drawRect(0, 0, 200, 300, mPaint);//200-300之间全部是最后的黑色        mPaint.setShader(mLinearGradient12);        canvas.drawRect(210, 0, 410, 300, mPaint);//0.5之后全部是黑色了        mPaint.setShader(mLinearGradient13);        canvas.drawRect(420, 0, 620, 300, mPaint); // LinearGradient的高度小于要绘制的矩形的高度时才会有重复、镜像等效果        canvas.drawLine(0, 310, 720, 310, mPaint);        //镜像效果        mPaint.setShader(mLinearGradient21);        canvas.drawRect(0, 320, 200, 620, mPaint);        mPaint.setShader(mLinearGradient22);        canvas.drawRect(210, 320, 410, 620, mPaint);        mPaint.setShader(mLinearGradient23);        canvas.drawRect(420, 320, 620, 620, mPaint);        canvas.drawLine(0, 630, 720, 630, mPaint);


//重复效果        mPaint.setShader(mLinearGradient31);        canvas.drawRect(0, 640, 200, 940, mPaint);        mPaint.setShader(mLinearGradient32);        canvas.drawRect(210, 640, 410, 940, mPaint);        mPaint.setShader(mLinearGradient33);        canvas.drawRect(420, 640, 620, 940, mPaint);    }}

public class MyShaderView extends View {
// Shader渲染器，专门用来渲染图像以及一些几何图形    private BitmapShader bitmapShader; //bitmap渲染器，主要用来渲染图像    private LinearGradient linearGradient; //线性渲染    private RadialGradient radialGradient; //环形渲染    private SweepGradient sweepGradient; //扫描渐变，围绕一个中心点扫描渐变就像电影里那种雷达扫描，用来梯度渲染    private ComposeShader composeShader; //混合渲染器，可以和其他几个子类组合起来使用    private Bitmap bitmap;    /**Bitmap的宽高*/    private int width, height;    private Paint paint;    /**渐变颜色数组*/    private final int[] colors = { Color.RED, Color.GREEN, Color.BLUE, Color.YELLOW };    /**用来指定颜色数组的相对位置，若为null则均匀分布*/    private final float[] positions = null;    public MyShaderView(Context context) {        super(context);        bitmap = ((BitmapDrawable) getResources().getDrawable(R.drawable.icon)).getBitmap();        width = bitmap.getWidth();        height = bitmap.getHeight();        paint = new Paint();    }    @SuppressLint("DrawAllocation")    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        canvas.drawColor(Color.WHITE); //背景色          //将Bitmap截取为圆形、圆角矩形        canvas.drawBitmap(bitmap, 0, 0, paint);//原图        bitmapShader = new BitmapShader(bitmap, TileMode.MIRROR, TileMode.MIRROR);        paint.setShader(bitmapShader);        canvas.drawOval(new RectF(width, 0, width * 2, height), paint);//圆形渲染图        canvas.drawRoundRect(width * 2, 0, width * 3, height, 30, 30, paint);//矩形渲染图        //绘制线性渐变的矩形        linearGradient = new LinearGradient(0, 200, 400, 400, colors, positions, TileMode.REPEAT);// 渐变起 初点/终点坐标 x/y 位置；        paint.setShader(linearGradient);        canvas.drawRect(0, 200, 400, 400, paint);//渲染范围最好和图形大小一致


//绘制环形渐变的圆和矩形        radialGradient = new RadialGradient(100, 500, 100, colors, positions, TileMode.REPEAT);// 中心坐标、半径        paint.setShader(radialGradient);        canvas.drawCircle(100, 500, 100, paint);        canvas.drawRect(200, 400, 300, 600, paint);        radialGradient = new RadialGradient(300, 500, 100, colors, positions, TileMode.MIRROR);        paint.setShader(radialGradient);        canvas.drawCircle(400, 500, 100, paint);        canvas.drawRect(500, 400, 600, 600, paint);        //绘制梯形渐变的矩形          sweepGradient = new SweepGradient(300, 710, colors, positions);//中心坐标        paint.setShader(sweepGradient);        canvas.drawRect(0, 610, 600, 810, paint);        //绘制混合渐变(线性与环形混合)的矩形        linearGradient = new LinearGradient(0, 820, 300, 1120, colors, positions, TileMode.REPEAT);        composeShader = new ComposeShader(linearGradient, bitmapShader, PorterDuff.Mode.SRC_OVER);        paint.setShader(composeShader);        canvas.drawRect(0, 820, 600, 1120, paint);    }}

来自为知笔记(Wiz)