Ios 从collectionview的结果显示collentionview

我在一个视图控制器中有两个集合视图。我希望第二个collection视图根据在第一个collectionview中选择的项目显示其内容。我已经让它工作到可以显示数据的程度，但我认为因为viewcontroller没有重新加载，所以它没有显示数据（细胞图像、描述等）。如何强制刷新视图，或者是否有更好的方法或在第二个collectionview中显示结果

课程的完整代码如下：

import UIKit
import Parse

private let reuseIdentifierPart = "CellPart"
private let reuseIdentifierPiece = "CellPiece"

class JourneyViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate {

    // passed packName from PackViewController
    var selectedPack: String!
    var selectedPart: String!

    @IBOutlet var collectionViewPart: UICollectionView!
    @IBOutlet var collectionViewPiece: UICollectionView!

    struct partStruct {
        var partName : String
        var partDescription : String
        var partTitle : String
        var partImage : PFFile
        var partID: String
    }

    struct pieceStruct {
        var pieceName : String
        //var pieceDescription : String
        //var pieceTitle : String
        var pieceImage : PFFile
    }

    var partArray = [partStruct]()
    var pieceArray = [pieceStruct]()

    var refreshView: UIViewController!


    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        // if selected pack not nil
        //--------------------------------------------- PART DISPLAY IN COLLECTION ----
        if let partsToDisplay = selectedPack {
            let partQuery = PFQuery(className: "Part")
                //have to create PFObject from selectedPack
                partQuery.whereKey("fromPack", equalTo: PFObject(outDataWithClassName: "Pack", objectId: selectedPack))
                partQuery.findObjectsInBackground(block: { (objectsArray, error) in
                    if error != nil {
                        print(error!)
                    } else if let parts = objectsArray {
                        for object in parts {

                            let arrayName = object.object(forKey: "partName") as! String
                            let arrayDescription = object.object(forKey: "partDescription") as! String
                            let arrayTitle = object.object(forKey: "partTitle") as! String
                            let arrayImage = object.object(forKey: "partImage") as! PFFile
                            //let arrayPoint = object.object(forKey: "fromPack") as! String
                            let arrayID = object.objectId as String!
                            self.partArray.append(partStruct(partName: arrayName, partDescription: arrayDescription, partTitle: arrayTitle, partImage: arrayImage, partID: arrayID!))
                        }
                        self.partArray = self.partArray.sorted{ $0.partName < $1.partName }
                        self.collectionViewPart?.reloadData()
                    }
                })
        }

    }//viewwillappear

    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        if collectionView == self.collectionViewPart {
            //--------------------------------------------- PIECE DISPLAY IN COLLECTION ----
            print("I selected an item in the Parts stack")
            selectedPart = self.partArray[indexPath.item].partID
            print("i selected item \(selectedPart)")

            if let piecesToDisplay = selectedPart {
                let pieceQuery = PFQuery(className: "Piece")
                //have to create PFObject from selectedPack
                pieceQuery.whereKey("fromPart", equalTo: PFObject(outDataWithClassName: "Part", objectId: selectedPart))
                pieceQuery.findObjectsInBackground(block: { (objectsArray, error) in
                    if error != nil {
                        print(error!)
                    } else if let pieces = objectsArray {
                        print(objectsArray?.count)
                        for object in pieces {

                            let arrayName = object.object(forKey: "pieceName") as! String
                            let arrayImage = object.object(forKey: "pieceImage") as! PFFile

                            self.pieceArray.append(pieceStruct(pieceName: arrayName, pieceImage: arrayImage))
                        }
                        self.pieceArray = self.pieceArray.sorted{ $0.pieceName < $1.pieceName }
                        self.collectionViewPiece?.reloadData()
                    }
                })

            } else {
                // this is for selecting somehitng in the vertical stack
                print("WERE GOING TO GO TO THE NEXT SCREEN AND PLAY THE SOUND FILE")

            }
        }
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        if collectionView == self.collectionViewPart {

            //pass this to the piece query when selected
            let selectedPart = self.partArray[indexPath.item].partName
            //--------------------------------------------- PART HOW TO DISPLAY EACH ITEM ----

            let cellPart: PartCollectionViewCell = collectionViewPart.dequeueReusableCell(withReuseIdentifier: reuseIdentifierPart, for: indexPath) as! PartCollectionViewCell

            //cellPart.labelCell.text = self.packArray[indexPath.item].packDescription
            //cellPart.labelCell.textColor = MyFunctions.UIColorFromHEX(hexValue: 0x0c1537)
            cellPart.imageCellPart.file = self.partArray[indexPath.item].partImage

            cellPart.imageCellPart.loadInBackground()

            cellPart.imageCellPart.layer.masksToBounds = true
            cellPart.imageCellPart.layer.cornerRadius = cellPart.imageCellPart.frame.height/2
            cellPart.imageCellPart.layer.borderWidth = 3
            cellPart.imageCellPart.layer.borderColor = MyFunctions.UIColorFromHEX(hexValue: 0x62aca2).cgColor

            return cellPart

        } else {
            //--------------------------------------------- PIECE HOW TO DISPLAY EACH ITEM ----

            let cellPiece: PieceCollectionViewCell = collectionViewPiece.dequeueReusableCell(withReuseIdentifier: reuseIdentifierPiece, for: indexPath) as! PieceCollectionViewCell

            //cellPiece.labelCell.text = self.packArray[indexPath.item].packDescription
            //cellPiece.labelCell.textColor = MyFunctions.UIColorFromHEX(hexValue: 0x0c1537)
            cellPiece.imageCellPiece.file = self.pieceArray[indexPath.item].pieceImage

            cellPiece.imageCellPiece.loadInBackground()

            cellPiece.imageCellPiece.layer.masksToBounds = true
            cellPiece.imageCellPiece.layer.cornerRadius = cellPiece.imageCellPiece.frame.height/2
            cellPiece.imageCellPiece.layer.borderWidth = 3
            cellPiece.imageCellPiece.layer.borderColor = MyFunctions.UIColorFromHEX(hexValue: 0x62aca2).cgColor

            return cellPiece
        }

    }
    // MARK: UICollectionViewDataSource

    func numberOfSections(in collectionView: UICollectionView) -> Int {
        return 1
    }


    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        if collectionView == self.collectionViewPart {
            return self.partArray.count
        } else {
            return self.pieceArray.count
        }
    }

    override func viewDidLoad() {
        super.viewDidLoad()

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()

    }


}//class

导入UIKit
导入解析
private let reuseIdentifierPart=“CellPart”
private let reuseIdentifierPiece=“CellPiece”
类JourneyViewController:UIViewController、UICollectionViewDataSource、UICollectionViewDelegate{
//从PackViewController传递packName
var selectedPack:String！
var selectedPart:String！
@IBOutlet var collectionViewPart:UICollectionView！
@IBVar collectionViewPiece:UICollectionView！
结构部分结构{
var partName:String
var partDescription:字符串
var partTitle:String
var partImage:PFFile
var partID:String
}
结构片结构{
变量名称：字符串
//变量说明：字符串
//变量标题：字符串
var-piecimage:PFFile
}
var partArray=[partStruct]（）
var pieceArray=[pieceStruct]（）
var refreshView:UIViewController！
覆盖函数视图将出现（uo动画：Bool）{
超级。视图将显示（动画）
//如果选择，则包装不为零
//---------------------------------------------集合中的零件显示----
如果让partsToDisplay=selectedPack{
让partQuery=PFQuery（类名：“Part”）
//必须从selectedPack创建PFObject
partQuery.whereKey（“fromPack”，equalTo:PFObject（outDataWithClassName:“Pack”，objectId:selectedPack））
findObjectsInBackground（块：{（objectsArray，错误）位于
如果错误！=nil{
打印（错误！）
}如果let parts=objectsArray，则为else{
用于零件中的对象{
让arrayName=object.object（forKey：“partName”）作为！字符串
让arrayDescription=object.object（forKey：“partDescription”）作为！字符串
让arrayTitle=object.object（forKey：“partTitle”）作为！字符串
让arrayImage=object.object（forKey:“partImage”）作为！PFFile
//让arrayPoint=object.object（forKey:“fromPack”）作为！字符串
让arrayID=object.objectId作为字符串！
self.partArray.append（partStruct（partName:arrayName，partDescription:arrayDescription，partTitle:arrayTitle，partImage:arrayImage，partID:arrayID！））
}
self.partArray=self.partArray.sorted{$0.partName<$1.partName}
self.collectionViewPart？.reloadData（）
}
})
}
}//视图将出现
func collectionView（collectionView:UICollectionView，didSelectItemAt indexPath:indexPath）{
如果collectionView==self.collectionViewPart{
//---------------------------------------------藏品陈列----
打印（“我在零件堆栈中选择了一个项目”）
selectedPart=self.partArray[indexPath.item].partID
打印（“我选择的项目\（选择的部分）”）
如果让工件显示=所选零件{
让pieceQuery=PFQuery（类名：“Piece”）
//必须从selectedPack创建PFObject
pieceQuery.whereKey（“fromPart”，equalTo:PFObject（outDataWithClassName:“Part”，objectId:selectedPart））
findObjectsInBackground（块：{（objectsArray，错误）位于
如果错误！=nil{
打印（错误！）
}否则，如果let pieces=objectsArray{
打印（objectsArray？.count）
一件一件的东西{
让arrayName=object.object（forKey：“pieceName”）作为！字符串
将arrayImage=object.object（forKey：“pieceImage”）设为！PFFile
self.pieceArray.append（pieceStruct（pieceName:arrayName，pieceImage:arrayImage））
}
self.pieceArray=self.pieceArray.sorted{$0.pieceName<$1.pieceName}
self.collectionViewPiece？.reloadData（）
}
})
}否则{
//这用于选择垂直堆栈中的某个元素
打印（“我们将转到下一个屏幕并播放声音文件”）
}
}
}
func collectionView（collectionView:UICollectionView，cellForItemAt indexPath:indexPath）->UICollectionViewCell{
如果collectionView==self.collectionViewPart{
//选中后将其传递给工件查询
让selectedPart=self.partArray[indexPath.item].partName
//---------------------------------------------部分介绍如何显示每个项目----
将cellPart:PartCollectionViewCell=collectionViewPart.DequeueReuseAbleCell（带ReuseIdentifier:reuseIdentifierPart，for:indexPath）设为！PartCollectionViewCell
//cellPart.labelCell.text=self.packArray[indexath.item].packDescription
//cellPart.labelCell.textColor=MyFunctions.UIColorFromHEX（hexValue:0x0c1537）
cellPart.imageCellPart.file=self.partArray[indexPath.item].partImage
cellPart.imageCellPart.loadInBackground（）
cellPart.imageCellPart.layer.masksToBounds=true
cellPart.imageCellPart.layer.cornerRadius=cellPart.imageCell
DispatchQueue.main.async(execute: {
            self.collectionViewPiece?.reloadData()
        })

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    if collectionView == self.collectionViewPart {
        //--------------------------------------------- PIECE DISPLAY IN COLLECTION ----
        print("I selected an item in the Parts stack")
        selectedPart = self.partArray[indexPath.item].partID
        print("i selected item \(selectedPart)")

        if let piecesToDisplay = selectedPart {
            let pieceQuery = PFQuery(className: "Piece")
            //have to create PFObject from selectedPack
            pieceQuery.whereKey("fromPart", equalTo: PFObject(outDataWithClassName: "Part", objectId: selectedPart))
            pieceQuery.findObjectsInBackground(block: { (objectsArray, error) in
                if error != nil {
                    print(error!)
                } else if let pieces = objectsArray {
                    print(objectsArray?.count)
                    for object in pieces {

                        let arrayName = object.object(forKey: "pieceName") as! String
                        let arrayImage = object.object(forKey: "pieceImage") as! PFFile

                        self.pieceArray.append(pieceStruct(pieceName: arrayName, pieceImage: arrayImage))
                    }
                    self.pieceArray = self.pieceArray.sorted{ $0.pieceName < $1.pieceName }
                    DispatchQueue.main.async(execute: {
            self.collectionViewPiece?.reloadData()
        })
                }
            })

        } else {
            // this is for selecting somehitng in the vertical stack
            print("WERE GOING TO GO TO THE NEXT SCREEN AND PLAY THE SOUND FILE")

        }
    }
}

  self.collectionViewPiece?.reloadData()
  self.collectionViewPiece?.layoutIfNeeded();

override func viewDidLoad() {
    super.viewDidLoad()
    collectionViewPart.delegate = self
    collectionViewPiece.delegate = self
    collectionViewPart.dataSource = self
    collectionViewPiece.dataSource = self
}