问如何在UIView中获取drawRect大小

EN

override func drawRect(rect: CGRect)
    let bds = DispatchQueue.main.sync {
        return self.bounds
    }
    // ....
}

- (void)layoutSubviews
{
    [super layoutSubviews];
    m_SelfBounds = self.bounds;
}

class MyTileView: UIView
{
  var drawBounds = CGRect(x: 0, y: 0, width: 0, height: 0)
  let drawBarrierQueue = DispatchQueue(label: "com.example.app",
                                             qos: .userInteractive, // draw operations require the highest priority threading available
                                             attributes: .concurrent,
                                             target: nil)

  override func layoutSubviews() {
    drawBarrierQueue.sync(flags: .barrier) { // a barrier operation waits for active operations to finish before starting, and prevents other operations from starting until this one has finished
      super.layoutSubviews();

      self.drawBounds = self.bounds

      // do other stuff that should hold up drawing
    }
  }

  override func draw(_ layer: CALayer, in ctx: CGContext)
  {
    drawBarrierQueue.sync {
      // do all of your drawing

      ctx.setFillColor(red: 1.0, green: 0, blue: 0, alpha: 1.0)
      ctx.fill(drawBounds)
    }
  }
}