Ios 动态调整集合视图单元格的大小

我更新了这个较旧的代码示例，但我还是一个新手，不知道如何修复这个错误：

在保存集合视图的类中：

var array = ["Just testing this out"]

现在在UICollectionViewDelegateFlowLayout扩展中：

private func estimateFrameForText(text: String) -> CGRect {
    //we make the height arbitrarily large so we don't undershoot height in calculation
    let height: CGFloat = 1000

    let size = CGSize(width: 398, height: height)
    let options = NSStringDrawingOptions.usesFontLeading.union(.usesLineFragmentOrigin)
    let attributes = [NSAttributedString.Key.font: UIFont.systemFont(ofSize: 17, weight: UIFont.Weight.light)]

    return NSString(string: text).boundingRect(with: size, options: options, attributes: attributes, context: nil)
}

private func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
    var height: CGFloat = 295
    //we are just measuring height so we add a padding constant to give the label some room to breathe!
     var padding: CGFloat = 14
    //estimate each cell's height
    if let text = array[indexPath.item].text {
          height = estimateFrameForText(text).height + padding
     }
     return CGSize(width: 398, height: height)    }

if let text = array[indexPath.item].text

@IBOutlet weak var TextPosted: UILabel!

另外：

private func estimateFrameForText(text: String) -> CGRect {
    //we make the height arbitrarily large so we don't undershoot height in calculation
    let height: CGFloat = 1000

    let size = CGSize(width: 398, height: height)
    let options = NSStringDrawingOptions.usesFontLeading.union(.usesLineFragmentOrigin)
    let attributes = [NSAttributedString.Key.font: UIFont.systemFont(ofSize: 17, weight: UIFont.Weight.light)]

    return NSString(string: text).boundingRect(with: size, options: options, attributes: attributes, context: nil)
}

private func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
    var height: CGFloat = 295
    //we are just measuring height so we add a padding constant to give the label some room to breathe!
     var padding: CGFloat = 14
    //estimate each cell's height
    if let text = array[indexPath.item].text {
          height = estimateFrameForText(text).height + padding
     }
     return CGSize(width: 398, height: height)    }

if let text = array[indexPath.item].text

@IBOutlet weak var TextPosted: UILabel!

这就是我得到错误的地方：

private func estimateFrameForText(text: String) -> CGRect {
    //we make the height arbitrarily large so we don't undershoot height in calculation
    let height: CGFloat = 1000

    let size = CGSize(width: 398, height: height)
    let options = NSStringDrawingOptions.usesFontLeading.union(.usesLineFragmentOrigin)
    let attributes = [NSAttributedString.Key.font: UIFont.systemFont(ofSize: 17, weight: UIFont.Weight.light)]

    return NSString(string: text).boundingRect(with: size, options: options, attributes: attributes, context: nil)
}

private func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
    var height: CGFloat = 295
    //we are just measuring height so we add a padding constant to give the label some room to breathe!
     var padding: CGFloat = 14
    //estimate each cell's height
    if let text = array[indexPath.item].text {
          height = estimateFrameForText(text).height + padding
     }
     return CGSize(width: 398, height: height)    }

if let text = array[indexPath.item].text

@IBOutlet weak var TextPosted: UILabel!

这是我不知道在哪里实现的集合视图单元格类的UILabel:

private func estimateFrameForText(text: String) -> CGRect {
    //we make the height arbitrarily large so we don't undershoot height in calculation
    let height: CGFloat = 1000

    let size = CGSize(width: 398, height: height)
    let options = NSStringDrawingOptions.usesFontLeading.union(.usesLineFragmentOrigin)
    let attributes = [NSAttributedString.Key.font: UIFont.systemFont(ofSize: 17, weight: UIFont.Weight.light)]

    return NSString(string: text).boundingRect(with: size, options: options, attributes: attributes, context: nil)
}

private func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
    var height: CGFloat = 295
    //we are just measuring height so we add a padding constant to give the label some room to breathe!
     var padding: CGFloat = 14
    //estimate each cell's height
    if let text = array[indexPath.item].text {
          height = estimateFrameForText(text).height + padding
     }
     return CGSize(width: 398, height: height)    }

if let text = array[indexPath.item].text

@IBOutlet weak var TextPosted: UILabel!

---

您的测试阵列需要进行一些调整。尝试将其声明为可选（因为它可能包含从某处加载的实际数据）

那么这个,

override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return array?.count ?? 0
}

然后更新CollectOnView sizeForItemAtIndexPath函数中的if-let语句：

if let text = array?[indexPath.item]{
}

顺便说一句，几天前我写了一个开源软件来测量像这样的东西的字符串大小

---

希望这有帮助。

您的测试阵列需要一些调整。尝试将其声明为可选（因为它可能包含从某处加载的实际数据）

那么这个,

override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return array?.count ?? 0
}

然后更新CollectOnView sizeForItemAtIndexPath函数中的if-let语句：

if let text = array?[indexPath.item]{
}

顺便说一句，几天前我写了一个开源软件来测量像这样的东西的字符串大小

---

希望这能有所帮助。

您会遇到什么错误？您希望看到什么？宽度和高度？你得到了什么错误？你期望动态地得到什么？宽度和高度？