一 使用场景

3DTouch在IOS应用中，主要有2种功能：
1 主屏幕上Icon快捷功能；

2 App内页面中的使用；

二 在APP中TableView中的使用

* 判断是否支持3DTouch

在使用之前，首先要判断当前设备是否支持3DTouch功能，不然可能造成崩溃，在使用3DTouch功能的控制器中这样判断：

if traitCollection.forceTouchCapability == .available {
        registerForPreviewing(with: self, sourceView: cell)
    }

* 设置代理，遵守协议，实现协议中需要实现的方法

 extension TouchTableViewController: UIViewControllerPreviewingDelegate {
func previewingContext(_ previewingContext: UIViewControllerPreviewing, viewControllerForLocation location: CGPoint) -> UIViewController? {
    if let index = tableView.indexPath(for: previewingContext.sourceView as! UITableViewCell) {
        let item = self.items[index.row] + "\(index.row + 1)"
        let touchDetail = TouchDetailViewController()
        touchDetail.item = item
        return touchDetail
    }
    return nil
}

func previewingContext(_ previewingContext: UIViewControllerPreviewing, commit viewControllerToCommit: UIViewController) {
    self.navigationController?.pushViewController(viewControllerToCommit, animated: true)        
}
}

* 设置上滑预览时快捷选项

然后在第二个控制器中，可以设置预览快捷键：

 override var previewActionItems: [UIPreviewActionItem] {
    let action1 = UIPreviewAction(title: item, style: .default) { [weak self](_, vc) in
        print(self?.item ?? "")
    }
    return [action1]
}

* 所有代码

//
//  TouchTableViewController.swift
//  Demo
//
//  Created by 王云 on 2017/11/29.
//  Copyright © 2017年 王云. All rights reserved.
//

import UIKit

class TouchTableViewController: UITableViewController {

var items: [String] = ["你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----", "你今天很漂亮----"]

    override func viewDidLoad() {
    super.viewDidLoad()
    view.backgroundColor = UIColor.white
    tableView.register(UITableViewCell.self, forCellReuseIdentifier: "TouchCellID")
}


// MARK: - Table view data source

override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return items.count
}

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "TouchCellID", for: indexPath)
    cell.textLabel?.text = items[indexPath.row] + "\(indexPath.row + 1)"
    if traitCollection.forceTouchCapability == .available {
        registerForPreviewing(with: self, sourceView: cell)
    }
    return cell
}

override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
    return 50
}

override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    let item = self.items[indexPath.row] + "\(indexPath.row + 1)"
    pushToTouchDetail(item: item)
}

func pushToTouchDetail(item: String) {
    let touchDetail = TouchDetailViewController()
    touchDetail.item = item
    self.navigationController?.pushViewController(touchDetail, animated: true)
}

}

extension TouchTableViewController: UIViewControllerPreviewingDelegate {
func previewingContext(_ previewingContext: UIViewControllerPreviewing, viewControllerForLocation location: CGPoint) -> UIViewController? {
    if let index = tableView.indexPath(for: previewingContext.sourceView as! UITableViewCell) {
        let item = self.items[index.row] + "\(index.row + 1)"
        let touchDetail = TouchDetailViewController()
        touchDetail.item = item
        return touchDetail
    }
    return nil
}

func previewingContext(_ previewingContext: UIViewControllerPreviewing, commit viewControllerToCommit: UIViewController) {
    self.navigationController?.pushViewController(viewControllerToCommit, animated: true)        
}
}

在第二个控制器中：

//
//  TouchDetailViewController.swift
//  Demo
//
//  Created by 王云 on 2017/11/29.
//  Copyright © 2017年 王云. All rights reserved.
//

import UIKit

class TouchDetailViewController: UIViewController {

var item: String!

fileprivate var titleLabel: UILabel!

override func viewDidLoad() {
    super.viewDidLoad()
    self.navigationItem.title = "TouchDetail"
    view.backgroundColor = UIColor.white
    setupUI()
    
    if let item = item {
        titleLabel.text = item
    }
    
}

func setupUI() {
    titleLabel = UILabel()
    titleLabel.textAlignment = .center
    titleLabel.textColor = UIColor.darkGray
    titleLabel.font = UIFont.systemFont(ofSize: 20)
    view.addSubview(titleLabel)
    
    titleLabel.snp.makeConstraints { (make) in
        make.centerX.equalToSuperview()
        make.centerY.equalToSuperview()
    }
}

override var previewActionItems: [UIPreviewActionItem] {
    let action1 = UIPreviewAction(title: item, style: .default) { [weak self](_, vc) in
        print(self?.item ?? "")
    }
    return [action1]
}


}