DrawView constructor

const DrawView({
  1. Key? key,
  2. required Size size,
  3. required dynamic onPaint(
    1. Canvas canvas,
    2. Size size
    ),
  4. Widget? child,
})

创建绘图板控件

@param size 绘图区域尺寸（必须） @param onPaint 绘图回调函数（必须） @param child 子控件（可选）

Implementation

const DrawView({
  Key? key,
  required this.size,
  required this.onPaint,
  this.child,
}) : super(key: key);