UICollectionView以编程方式 [英] UICollectionView Programmatically

问题描述

我在故事板中创建了我自己的窗口，如下所示：

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        // Override point for customization after application launch.
        window = UIWindow(frame: UIScreen.main.bounds)
        window?.makeKeyAndVisible()
        window?.rootViewController = UINavigationController(rootViewController: HomeController())
        return true
    }

当我的类继承 UIViewController时，这实际上工作正常。

class HomeController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        view.backgroundColor = UIColor.red
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}

现在当我使用 UICollectionViewController继承我的类：

class HomeController: UICollectionViewController {

        override func viewDidLoad() {
            super.viewDidLoad()
            // Do any additional setup after loading the view, typically from a nib.
            Collectionview.backgroundColor = UIColor.red
        }

        override func didReceiveMemoryWarning() {
            super.didReceiveMemoryWarning()
            // Dispose of any resources that can be recreated.
        }


    }

在运行时它给我一个错误说：

At runtime it gives me an error saying:

由于未捕获的异常而终止应用
'NSInvalidArgumentException'，原因：'UICollectionView必须是
初始化为非零布局参数'
***第一次调用堆栈：

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'UICollectionView must be initialized with a non-nil layout parameter' *** First throw call stack:

在我的理解中我要求我为 UICollectionView 提供布局。如果我错了，请在这里告诉我。我试过这个 - ：

In my understanding it is asking me to give layout for UICollectionView.Correct me here if I am wrong.So I tried this-:

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        // Override point for customization after application launch.
        window = UIWindow(frame: UIScreen.main.bounds)
        window?.makeKeyAndVisible()
        let layout = UICollectionViewFlowLayout()
        window?.rootViewController = UINavigationController(rootViewController: HomeController(UICollectionViewLayout: layout))
        return true
    }

但仍然结束有错误：

参数标签'UICollectionViewLayout'与任何可用的
重载都不匹配。

Argument labels 'UICollectionViewLayout' do not match any available overloads.

我使用了错误的 swift3语法吗？如果是，解决这个问题是正确的。

Am I using a wrong swift3 syntax? If yes what is correct to solve out this issue.

推荐答案

你需要使用 UICollectionViewController 指定的intialiser如下。

You need to use UICollectionViewController's designated intialiser as below.

let layout = UICollectionViewLayout()
let homeViewController = HomeController(collectionViewLayout: layout)
window?.rootViewController = UINavigationController(rootViewController: homeViewController)

以及那么，您需要修改 HomeViewController 来实现 UICollectionViewDataSource 所需的方法。

Along with that, you will need to modify you HomeViewController to implement UICollectionViewDataSource required methods.

override func viewDidLoad() {
        super.viewDidLoad()

        // Uncomment the following line to preserve selection between presentations
        // self.clearsSelectionOnViewWillAppear = false

        // Register cell classes
        self.collectionView!.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "Cell")

        // Do any additional setup after loading the view.
    }


// MARK: UICollectionViewDataSource

    override func numberOfSections(in collectionView: UICollectionView) -> Int {
        // #warning Incomplete implementation, return the number of sections
        return 0
    }


    override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        // #warning Incomplete implementation, return the number of items
        return 0
    }

    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath)

        // Configure the cell

        return cell
    }

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