我一直在开发一个具有UICollectionView的应用程序，其工作方式与主屏幕类似，UICollectionViewCells作为不同的页面（水平滚动）。我在每个单元格上添加了一个文本字段进行编辑，但是当我单击文本字段时，键盘出现时单元格高度会延长。键盘隐藏后，单元格高度保持不变。我一直在寻找这个问题的答案，但我没有遇到一个有效的解决方案。
我试图使布局无效，将translatesAutoresizingMaskIntoConstraints设置为false，并直接将内容偏移设置为零。这些选项都没有解决问题。
以下是我的代码：
private let reuseIdentifier = ["Cell1", "Cell2", "Cell3", "Cell4", "Cell5"]
let navi_btn_array: [UIButton] = [navi_home_btn, navi_gavel_btn, navi_orders_btn, navi_profile_btn, navi_lightning_btn]
var collectionView: UICollectionView = {
var layout = UICollectionViewFlowLayout();
layout.sectionInset = UIEdgeInsets.zero
var cv = UICollectionView(frame: .zero, collectionViewLayout: layout);
cv.autoresizesSubviews = false
cv.contentInset = UIEdgeInsets.zero
cv.translatesAutoresizingMaskIntoConstraints = false;
return cv;
}();
class MainCVC: UICollectionViewController,UICollectionViewDelegateFlowLayout, CLLocationManagerDelegate, UITextFieldDelegate {
override func viewDidLoad() {
super.viewDidLoad()
collectionView?.register(SimpleDispensaryPage_Cell.self, forCellWithReuseIdentifier: reuseIdentifier[0])
collectionView?.delegate = self
collectionView?.dataSource = self
collectionView?.isPagingEnabled = true
let nc:NotificationCenter = NotificationCenter.default
nc.addObserver(self, selector: #selector(keyboardDidShow(notification:)), name: NSNotification.Name.UIKeyboardDidShow, object: nil)
nc.addObserver(self, selector: #selector(keyboardDidHide(notification:)), name: NSNotification.Name.UIKeyboardDidHide, object: nil)
}
@objc func keyboardDidShow(notification: Notification){
collectionViewLayout.invalidateLayout()
collectionView?.contentOffset.y = 0
}
@objc func keyboardDidHide(notification: Notification){
collectionViewLayout.invalidateLayout()
collectionView?.contentOffset.y = 0
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 5
}
override func numberOfSections(in collectionView: UICollectionView) -> Int {
return 1
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier[0], for: indexPath)
cell.backgroundColor = Custom_Colors.color_pine.withAlphaComponent(0.5)
var txt_fld = UITextField()
txt_fld.frame = CGRect(x: 0, y: 50, width: 100, height: 50)
cell_label.text = "Placeholder #"+String(indexPath.item)
cell_label.textAlignment = .center
cell.addSubview(cell_label)
return cell
}
}
}
运行时我也会收到此错误：
2019-03-14 11:41:20.770799-0700 app[57379:5390785] the item height must be less than the height of the UICollectionView minus the section insets top and bottom values, minus the content insets top and bottom values.
2019-03-14 11:41:20.771043-0700 app[57379:5390785] The relevant UICollectionViewFlowLayout instance is <UICollectionViewFlowLayout: 0x7fda15c13f40>, and it is attached to <UICollectionView: 0x7fda1706f000; frame = (0 0; 375 730.8); clipsToBounds = YES; autoresize = W+H; gestureRecognizers = <NSArray: 0x600000447bc0>; layer = <CALayer: 0x600000437720>; contentOffset: {8, -38.333333333333336}; contentSize: {1891, 579}; adjustedContentInset: {0, 0, 151.79999999999995, 0}> collection view layout: <UICollectionViewFlowLayout: 0x7fda15c13f40>.
2019-03-14 11:41:20.771245-0700 app[57379:5390785] Make a symbolic breakpoint at UICollectionViewFlowLayoutBreakForInvalidSizes to catch this in the debugger.
你在这里有一些奇怪的设置。我建议做一些改变：
1 - 永远不要在collectionView（_，cellForItemAt ...）中添加子视图。每次重复使用该单元时，这将导致多次添加。子视图应该由单元格添加（并且最好在创建时）。
2 - 删除cv.autoresizesSubviews = false和cv.translatesAutoresizingMaskIntoConstraints = false。
3 - 如果您想为单元格设置固定大小，可以设置layout.delegate = self并实现以下方法：
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: screenWidth, height: screenHeight)
}
4 - 如果你真的只想要几页，为什么不使用UIPageViewController？