Android用Path类绘制路径

ゞ浴缸里的玫瑰 2022-08-03 08:40 160阅读 0赞

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);
    			//创建并初始化Path
    			path = new Path();
    			path.moveTo(0, 0);
    			for(int i = 1; i <= 15; i++) {
    				//生成15个点，随机生成他们的Y坐标，并将它们连成一条Path
    				path.lineTo(i*20, (float)Math.random()*60);
    			}
    			//初始化7个颜色
    			colors = new int[]{Color.BLACK, Color.BLUE, Color.CYAN, Color.GREEN,
    					Color.MAGENTA, Color.RED, Color.YELLOW};
    		}
    		@Override
    		protected void onDraw(Canvas canvas) {
    			//将背景色填充成白色
    			canvas.drawColor(Color.WHITE);
    			//----------下面开始初始化7中路径效果----------
    			//不使用路径效果
    			effects[0] = null;
    			//使用CornerPathEffect路径效果
    			effects[1] = new CornerPathEffect(10);
    			//初始化(不连续的、离散的)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PathDashPathEffects
    			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ComposePathEffect
    			effects[5] = new ComposePathEffect(effects[2], effects[4]);
    			//初始化SumPathEffect
    			effects[6] = new SumPathEffect(effects[4], effects[3]);
    			//将画布移动到(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();
    		}
    	}