canvas.drawLine(hookStart.x, hookStart.y, hookMiddle.x + 2, hookMiddle.y + 2, mUncheckPaint);修改为canvas.drawLine(hookStart.x, hookStart.y, hookMiddle.x + 0, hookMiddle.y + 0, mUncheckPaint);，加2完全没必要，如果加2，控件宽高变小之后会不对齐的
canvas.drawLine(hookStart.x, hookStart.y, hookMiddle.x + 2, hookMiddle.y + 2, mUncheckPaint);修改为canvas.drawLine(hookStart.x, hookStart.y, hookMiddle.x + 0, hookMiddle.y + 0, mUncheckPaint);，加2完全没必要，如果加2，控件宽高变小之后会不对齐的