[Android]path绘图demo

class MyView extends View {

    float phase;

    PathEffect[] effects = new PathEffect[7];

    int[] colors;

    private Paint paint;

    Path path;

    public MyView(Context context) {

        super(context);

        paint = new Paint();

        paint.setStyle(Paint.Style.STROKE);

        paint.setStrokeWidth(4);

        // 创建初始化Path

        path = new Path();

        path.moveTo(0, 0); // 设置绘制的起点在左上角

        for (int i = 1; i <= 15; i++) {

            path.lineTo(i * 20, (float) Math.random() * 60);

        }

        colors = new int[] { Color.BLACK, Color.BLUE, Color.CYAN, Color.GREEN, Color.MAGENTA, Color.RED,
                Color.YELLOW };

    }

    @Override
    protected void onDraw(Canvas canvas) {

        // 将背景填充成白色

        canvas.drawColor(Color.WHITE);

        // -------下面开始初始化7中路径的效果

        // 使用路径效果

        effects[0] = null;

        // 使用CornerPathEffect路径效果

        effects[1] = new CornerPathEffect(10);

        // 初始化DiscretePathEffect

        effects[2] = new DiscretePathEffect(3.0f, 5.0f);

        // 初始化DashPathEffect

        effects[3] = new DashPathEffect(new float[] { 20, 10, 5, 10 }, phase);

        // 初始化PathDashPathEffect

        Path p = new Path();

        p.addRect(0, 0, 8, 8, Path.Direction.CCW);

        effects[4] = new PathDashPathEffect(p, 12, phase, PathDashPathEffect.Style.ROTATE);

        // 初始化PathDashPathEffect

        effects[5] = new ComposePathEffect(effects[2], effects[4]);

        effects[6] = new SumPathEffect(effects[4], effects[3]);

        // 将画布移到8,8处开始绘制

        canvas.translate(8, 8);

        // 依次使用7中不同路径效果,7种不 同的颜色来绘制路径

        for (int i = 0; i < effects.length; i++)

        {

            paint.setPathEffect(effects[i]);

            paint.setColor(colors[i]);

            canvas.drawPath(path, paint);

            canvas.translate(0, 60);

        }

        // 改变phase值,形成动画效果

        phase += 1;

        invalidate();

    }

}