swift - 如何在 NSTextView 周围绘制边框

Question

我只是想在 NSTextView 周围绘制一点黑色边框，但遇到了麻烦。下面的代码是 NSTextView 的子类:

override init(frame: NSRect, textContainer: NSTextContainer?)
{
    super.init(frame:frame, textContainer: textContainer)

    self.wantsLayer = true
    self.layer?.borderColor = NSColor.black.cgColor
    self.layer?.borderWidth = 1.0
    self.layer?.cornerRadius = 0.0
}

self.wantsLayer = true 代码导致 NSTextView 消失。还有其他方法可以实现这一点吗？

编辑:这就是我将 NSTextView 又名 PageView 添加到其父 view 的方式:

    let textContainer = NSTextContainer()
    textContainer.widthTracksTextView = true
    textContainer.heightTracksTextView = true

    let pageView = PageView(frame: CGRect(x: 0, y: pagesViewOriginY, width: self.paperSize.width, height: self.paperSize.height), textContainer: textContainer)
    self.addSubview(pageView);

    self.layoutManager.addTextContainer(textContainer);

Answer 1

另一种选择是为 TextView 创建一个单独的类并使用draw()来提供框架:

class TextView: NSTextView {
override func draw(_ rect: NSRect) {
  super.draw(rect)
  let border:NSBezierPath = NSBezierPath(rect: bounds)
  let borderColor = NSColor.black
  borderColor.set()
  border.lineWidth = 2.0
  border.stroke()
}
}