Canvas属性

drawRect()画矩形

• drawRect(float left, float top, float right, float bottom, @NonNull Paint paint)
• drawRect(@NonNull Rect r, @NonNull Paint paint)
• drawRect(@NonNull RectF r, @NonNull Paint paint)
  两者差别就是：Rect 坐标为integer 而RectF 坐标为float

drawCricle() 画圆形

• drawCircle(float cx, float cy, float radius, @NonNull Paint paint)
  radius:圆的半径
  cx:圆心的x坐标
  cy:圆心的y坐标

drawArc()画扇形

• drawArc(@NonNull RectF oval, float startAngle, float sweepAngle, boolean useCenter, @NonNull Paint paint)
  startAngle:开始绘制的角度
  sweepAngle:扇形扫过的角度,并不是停止的角度,停止的角度=startAngle+sweepAngle
  userCenter:true有焦点圆形;false没有焦点圆心

drawBitmap()画Bitmap

• drawBitmap(@NonNull Bitmap bitmap, float left, float top, @Nullable Paint paint)
  left:左上角横坐标
  top:左上角纵坐标

drawText()画文字

• drawText(@NonNull String text, float x, float y, @NonNull Paint paint)

drawLine()画线

• drawLine(float startX, float startY, float stopX, float stopY, @NonNull Paint paint)

drawRoundRect()画圆角矩形

drawOval()画椭圆