現(xiàn)在很多app功能點(diǎn)都非常多雌团，如果將功能點(diǎn)都放在首頁，這樣就感覺比較亂聘惦，而且功能的主次也不容易區(qū)分某饰，用戶有些功能點(diǎn)是不需要經(jīng)常操作的儒恋，像支付寶的功能點(diǎn)就非常多，因此支持用戶自定義排序就非常有必要黔漂，筆者現(xiàn)在的項(xiàng)目功能點(diǎn)也非常之多诫尽，因此也支持用戶自定義排序，用戶可以自己選擇在首頁展示多少個(gè)功能炬守，功能的順序牧嫉，用戶也可以自己設(shè)置。這是項(xiàng)目的效果圖：

屏幕快照 2017-09-23 09.46.13.png

屏幕快照 2017-09-23 09.46.24.png

其中首頁只展示7個(gè)功能入口减途，其余的入口用戶可以進(jìn)入去全部里面查看酣藻，且所有功能入口可拖拽排序，用戶可以根據(jù)自己的需要在首頁展示自己常用的功能鳍置。下面就給出該功能的實(shí)現(xiàn)思路辽剧。
這種九宮格的東西利用collectionView實(shí)現(xiàn)最簡單，對(duì)于iOS9.0以上系統(tǒng)税产，collectionView已支持拖拽排序怕轿，兩個(gè)代理方法即可：

func collectionView(_ collectionView: UICollectionView, canMoveItemAt indexPath: IndexPath) -> Bool 
func collectionView(_ collectionView: UICollectionView, moveItemAt sourceIndexPath: IndexPath, to destinationIndexPath: IndexPath) 

iOS9以下系統(tǒng)的實(shí)現(xiàn)思路：

1.給cell添加長按手勢

//
//  YRFunctionConfigCollectionViewCell.swift
//  YouRen
//
//  Created by MrZhaoCn on 2017/9/21.
//  Copyright ? 2017年 Zhou Shaolin. All rights reserved.
//

import UIKit
protocol YRFunctionConfigCollectionViewCellDelegate:NSObjectProtocol {
    func configButtonClik(view:YRFunctionConfigCollectionViewCell,id:Int32)
    func dragCellGestureAction(gesture:UIGestureRecognizer,id:Int32)
}
class YRFunctionConfigCollectionViewCell: UICollectionViewCell {
    
    @IBOutlet var configButton: UIButton!
    @IBOutlet var iconImageView: UIImageView!
    @IBOutlet var titleLabel: UILabel!
    @IBAction func configActionButtonClik(_ sender: Any) {
        guard let homeModel = homeModel else {
            return
        }
        delegate?.configButtonClik(view: self, id: homeModel.id)
    }
    weak var delegate:YRFunctionConfigCollectionViewCellDelegate?
    private var homeModel:YRHomeModuleModel?
    override func awakeFromNib() {
        super.awakeFromNib()
        //添加手勢
        let longPress = UILongPressGestureRecognizer(target: self, action: #selector(gestureAction(gesture:)))
        self.addGestureRecognizer(longPress)
    }
    func gestureAction(gesture:UIGestureRecognizer) {
        guard let delegate = delegate else {
            return
        }
        guard let homeModel = homeModel else {
            return
        }
        delegate.dragSortCellGestureAction(gesture:gesture,id: homeModel.id)
    }
}

2.長按開始時(shí)截取cell視圖，并將視圖添加到collectionView上辟拷，并隱藏該cell

func dragCellGestureAction(gesture: UIGestureRecognizer,id:Int32) {
        //判斷是哪個(gè)collectionView
        var collectionView:UICollectionView = deleteCollectionView
        for item in deleteHomeModels {
            if item.id == id {
                collectionView = deleteCollectionView
                break
            }
        }
        for item in addHomeModels {
            if item.id == id {
                collectionView = addCollectionView
                break
            }
        }
        let point = gesture.location(in: collectionView)
        switch gesture.state {
        case UIGestureRecognizerState.began:
            dragBegan(gesture:gesture,point: point,collectionView:collectionView)
        case UIGestureRecognizerState.changed:
            drageChang(gesture: gesture,point: point, collectionView: collectionView)
        case UIGestureRecognizerState.ended:
            drageEnd(point: point, collectionView: collectionView)
        default: break
        }
    }
//MARK: - 長按開始
func dragBegan(gesture: UIGestureRecognizer,point: CGPoint,collectionView:UICollectionView) {
        indexPath = collectionView.indexPathForItem(at: point)
        if indexPath == nil {
            return
        }
        let item = collectionView.cellForItem(at: indexPath!) as? YRFunctionConfigCollectionViewCell
       //截取視圖
        self.snapItem = item?.snapshotView(afterScreenUpdates: true)
        self.snapItem?.center = (item?.center)!
        collectionView.addSubview(self.snapItem ?? UIView())
       //原cell隱藏
        item?.isHidden = true
        startPoint = gesture.location(in: collectionView)
    }

3.在拖拽過程中撞羽，根據(jù)手勢的位置，不斷調(diào)整截取視圖的位置,交換數(shù)據(jù)源.

//MARK: - 長按過程
  func drageChang(gesture: UIGestureRecognizer,point: CGPoint,collectionView:UICollectionView) {
        if indexPath == nil {
            return
        }
        let tranX = gesture.location(ofTouch: 0, in: collectionView).x - startPoint.x
        let tranY = gesture.location(ofTouch: 0, in: collectionView).y - startPoint.y
        //設(shè)置截圖視圖位置
        self.snapItem?.center = __CGPointApplyAffineTransform((self.snapItem?.center)!, CGAffineTransform(translationX: tranX, y: tranY))
        startPoint = gesture.location(ofTouch: 0, in: collectionView)
        targetIndexPath = collectionView.indexPathForItem(at: point)
        if targetIndexPath == nil {
            return
        }
        // 更新數(shù)據(jù)
        if collectionView == deleteCollectionView {
            let obj = deleteHomeModels[indexPath!.item]
            deleteHomeModels.remove(at: indexPath!.item)
            deleteHomeModels.insert(obj, at: targetIndexPath!.item)
        } else {
            let obj = addHomeModels[indexPath!.item]
            addHomeModels.remove(at: indexPath!.item)
            addHomeModels.insert(obj, at: targetIndexPath!.item)
        }
        //交換位置
        collectionView.moveItem(at: indexPath!, to: targetIndexPath!)
        indexPath = targetIndexPath
    }

4.手勢結(jié)束時(shí)獲取手勢的位置,并移除掉截取的視圖即可衫冻。

//MARK: - 長按結(jié)束
   func drageEnd(point: CGPoint,collectionView:UICollectionView) {
        if indexPath == nil {
            return
        }
        let endCell = collectionView.cellForItem(at: indexPath!)
        UIView.animate(withDuration: 0.25, animations: 
            self.snapItem?.center = (endCell?.center)!
        }, completion: {
            (finish) -> () in
            endCell?.isHidden = false
            self.snapItem?.removeFromSuperview()
            self.indexPath = nil
        })
    }

注：筆者的項(xiàng)目要求上面的功能刪除完時(shí)也要留有固定大小的區(qū)域同來添加功能诀紊，因此采用兩個(gè)collectionView實(shí)現(xiàn)隅俘，但思路是一樣的渡紫。其中deleteCollectionView為上面已添加的，deleteHomeModels為該數(shù)據(jù)源考赛。addCollectionView為待添加的惕澎，addHomeModels為其數(shù)據(jù)源。