标签: uicollectionviewflowlayout

您好我想将collectionView完全显示为上图.我知道它负责UICollectionViewFlowLayout,但无法做到.非常感谢帮助.这是我的代码

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
     let yourWidth = (collectionView.bounds.width - 4) / 3.0
     let yourHeight = yourWidth
     return CGSize(width: yourWidth, height: yourHeight)
}

警告： The item width must be less than the width of the UICollectionView minus the section insets left and right values, minus the content insets left and right values.

代码：

extension SaleViewController {
    override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator){
        checkEstimatedSize()
    }

    func checkEstimatedSize(){
        if(DeviceType.IS_IPAD || UIDevice.current.orientation == .landscapeLeft || UIDevice.current.orientation == .landscapeRight){
            if let layout = myCollectionView.collectionViewLayout as? UICollectionViewFlowLayout {
                layout.estimatedItemSize = CGSize(width: 1, height: 1)
                layout.invalidateLayout()
            }
        }else{
            if let layout = myCollectionView.collectionViewLayout as? UICollectionViewFlowLayout {
                layout.estimatedItemSize …

我在用

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    return CGSize(width: 400, height: 600)
}

指定 myCollectionView的像元大小。它工作正常，但是一旦我(UILabel.width == ContentView.width)在单元格UILabel内部添加宽度约束ContentView，单元格的宽度就会缩小到 的固有宽度UILabel。

我正在使用UICollectionViewDelegateFlowLayout水平滚动。

如何强制坚持ContentView我指定的单元格大小并让子视图遵循自动布局约束？

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    
    
    if collectionView == self.collectionViewVideo {

        var collectionViewSize = collectionViewVideo.frame.size
        collectionViewSize.width = collectionViewSize.width/3.0 //Display Three elements in a row.
        return collectionViewSize
    } else {
        return CGSize(width: 60, height: 60)
    }
    
    
}

您好，我想使用 uicollectionview 进行拖放。当执行拖放时，它正在移动内容，我想像照片中那样进行操作。我想让盒子自己搬。例如; 当我将照片拖动到 4 时，我应该保留带有完整测量值的红色区域。将照片 6 交换到照片 1，就像将照片 3 移到左侧一样。我在 uicollectionview 中研究了很多，但我无法\xe2\x80\x99 找到类似的东西。请帮我

import UIKit\n\nfinal class ViewController: UIViewController {\n\n@IBOutlet weak var collectionView: UICollectionView!\n\n var cellIds = ["image 1","image 2","image 3","image 4","image 5","6","7"]\n  override func viewDidLoad() {\n    super.viewDidLoad()\n\n    let flowLayout = collectionView.collectionViewLayout as! UICollectionViewFlowLayout\n    flowLayout.estimatedItemSize = CGSize(width: 200, height: 10)\n\n    let gestureRecognizer = UILongPressGestureRecognizer(target: self,\n                                                         action: #selector(self.handleLongPress(gestureRecognizer:)))\n    collectionView.addGestureRecognizer(gestureRecognizer)\n}\n\n@objc func handleLongPress(gestureRecognizer: UILongPressGestureRecognizer) {\n\n    guard let view = gestureRecognizer.view else { return }\n    let location = gestureRecognizer.location(in: view)\n\n    switch gestureRecognizer.state {\n …