§2绘制2D图像(635KB).pptVIP

绘制2D图像 本讲大纲： 1、绘制几何图形 2、绘制文本 支持网站： 3、绘制路径 4、绘制图片 5、范例1：绘制Android的机器人 6、范例2：实现简易涂鸭板 方法 描述 举例 绘图效果 drawArc(RectF oval, float startAngle, float sweepAngle, boolean useCenter, Paint paint) 绘制弧 RectF rectf=new RectF(10, 20, 100, 110); canvas.drawArc(rectf, 0, 60, true, paint); RectF rectf1=new RectF(10, 20, 100, 110); canvas.drawArc(rectf1, 0, 60, false, paint); drawCircle(float cx, float cy, float radius, Paint paint) 绘制圆形 paint.setStyle(Style.STROKE); canvas.drawCircle(50, 50, 15, paint); drawLine(float startX, float startY, float stopX, float stopY, Paint paint) 绘制一条线 canvas.drawLine(100, 10, 150, 10, paint); drawLines(float[] pts, Paint paint) 绘制多条线 canvas.drawLines(new float[]{10,10, 30,10, 30,10, 15,30, 15,30, 10,10}, paint); drawOval(RectF oval, Paint paint) 绘制椭圆 RectF rectf=new RectF(40, 20, 80, 40); canvas.drawOval(rectf,paint); drawPoint(float x, float y, Paint paint) 绘制一个点 canvas.drawPoint(10, 10, paint); drawPoints(float[] pts, Paint paint) 绘制多个点 canvas.drawPoints(new float[]{10,10, 15,10, 20,15, 25,10, 30,10}, paint); drawRect(float left, float top, float right, float bottom, Paint paint) 绘制矩形 canvas.drawRect(10, 10, 40, 30, paint); drawRoundRect(RectF rect, float rx, float ry, Paint paint) 绘制圆角矩形 RectF rectf=new RectF(40, 20, 80, 40); canvas.drawRoundRect(rectf, 6, 6, paint); 绘制几何图形 绘制文本 1．drawText()方法 drawText(String text, float x, float y, Paint paint) 2．drawPosText()方法 drawPosText(String text, float[] pos, Paint paint) 绘制路径 1．创建路径 2．将定义好的路径绘制在画布上 使用Canvas类提供的drawPath()方法可以将定义好的路径绘制在画布上。 方法 描述 addArc(RectF oval, float startAngle, float sweepAngle) 添加弧形路径 addCircle(float x, float y, float radius, Path.Direction dir) 添加圆形路径 addOval(RectF oval, Path.Direction dir) 添加椭圆形路径 addRect(RectF rect, Path.Direction dir) 添加矩形路径 addRoundRect(RectF rect, float rx, float ry, Path.Direction dir) 添加圆角矩形路径 moveTo(float x, float y) 设置开始绘制直线的起始点 lineTo(float x, float y) 在moveTo()方法设置的起始点与该方法指定的结束点之间画一条直线，如果在调用该方法之前没使用moveTo()方法设置起始点，那么将从（0,0）点开始绘制直线 quadTo(float x1, float y1