fileprivate let tv:NSTextView = {

        let textView = NSTextView(frame: NSMakeRect(30, 30, 200, 30))

        return textView

    }();

override func viewDidLoad() {

        super.viewDidLoad()

        // Do any additional setup after loading the view.

        self.view.addSubview(self.tv);

        //1设置textStorage的代理，实现NSTextStorageDelegate代理协议的textStorageDidProcessEiting方法

        //实现响应用户输入

        tv.textStorage?.delegate = self;

        /***

         textStorage存储富文本

         **/

        let attributedString = NSMutableAttributedString(string: "attringbutedString" as String)

        attributedString.addAttributes([NSAttributedString.Key.foregroundColor : NSColor.green as Any], range: NSMakeRange(0, 5))

        attributedString.addAttributes([NSAttributedString.Key.font : NSFont(name: "宋体", size: 14) as Any], range: NSMakeRange(5, 10))

        tv.textStorage?.setAttributedString(attributedString)

    }

//实现NSTextStorageDelegate代理协议的textStorageDidProcessEiting方法

    func textStorage(_ textStorage: NSTextStorage, didProcessEditing editedMask: NSTextStorageEditActions, range editedRange: NSRange, changeInLength delta: Int) {

        //文本框高度根据文字高度自适应增长

        self.perform(#selector(self.setHeightToMatchContents), with: nil, afterDelay: 0.0)

    }

    //计算当前输入文本的高度

    func naturalSize()->NSSize {

        let bounds:NSRect = self.tv.bounds;

        let layoutManager:NSLayoutManager = self.tv.textStorage!.layoutManagers[0]

        let textContainer:NSTextContainer = layoutManager.textContainers[0]

        textContainer.containerSize = NSMakeSize(bounds.size.width, 1.0e7)

        layoutManager.glyphRange(for: textContainer)

        let naturalSize: NSSize? = layoutManager.usedRect(for: textContainer).size

        return naturalSize!

    }

    //根据文本高度修改文本框对应的滚动条高度

   @objc func setHeightToMatchContents() {

        let naturalSize: NSSize = self.naturalSize()

        if let scrollView = self.tv.enclosingScrollView {

            let frame = scrollView.frame

            scrollView.frame = NSMakeRect(frame.origin.x, frame.origin.y, frame.size.width, naturalSize.height + 4)

        }

    }

}