我试图创建一个集合视图,其中单元格显示具有可变长度的字符串.
Im使用此功能设置单元格布局：
func collectionView(collectionView : UICollectionView,layout collectionViewLayout:UICollectionViewLayout,sizeForItemAtIndexPath indexPath:NSIndexPath) -> CGSize
{
var cellSize:CGSize = CGSizeMake(self.whyCollectionView.frame.width,86)
return cellSize
}
我想做的是根据我的cell.labelString.utf16Count长度操纵cellSize.height.
基本逻辑就是这样
if((cell.labelString.text) > 70){
cellSize.height = x
}
else{
cellSize.height = y
}
但是,我无法检索我的单元格标签长度,总是返回nil. (我觉得没有加载…
为了更好的理解,这里是完整的代码：
// WhyCell section
var whyData:NSMutableArray! = NSMutableArray()
var textLength:Int!
@IBOutlet weak var whyCollectionView: UICollectionView!
//Loading data
@IBAction func loadData() {
whyData.removeAllObjects()
var findWhyData:PFQuery = PFQuery(className: "PlacesWhy")
findWhyData.whereKey("placeName",equalTo: placeName)
findWhyData.findObjectsInBackgroundWithBlock({
(objects:[AnyObject]!,error:NSError!)->Void in
if (error == nil) {
for object in objects {
self.whyData.addObject(object)
}
let array:NSArray = self.whyData.reverSEObjectEnumerator().allObjects
self.whyData = array.mutableCopy() as NSMutableArray
self.whyCollectionView.reloadData()
println("loadData completed. datacount is \(self.whyData.count)")
}
})
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
self.loadData()
}
func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
return 1
}
func collectionView(collectionView: UICollectionView,numberOfItemsInSection section: Int) -> Int {
return whyData.count
}
func collectionView(collectionView: UICollectionView,cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell:whyCollectionViewCell = whyCollectionView.dequeueReusableCellWithReuseIdentifier("whyCell",forIndexPath: indexPath) as whyCollectionViewCell
// Loading content from NSMutableArray to cell
let therew:PFObject = self.whyData.objectAtIndex(indexPath.row) as PFObject
cell.userWhy.text = therew.objectForKey("why") as String!
textLength = (therew.objectForKey("why") as String!).utf16Count
self.whyCollectionView.layoutSubviews()
// Displaying user information
var whatUser:PFQuery = PFUser.query()
whatUser.whereKey("objectId",equalTo: therew.objectForKey("reasonGivenBy").objectId)
whatUser.findObjectsInBackgroundWithBlock({
(objects: [AnyObject]!,error: NSError!)->Void in
if !(error != nil) {
if let user:PFUser = (objects as NSArray).lastObject as? PFUser {
cell.userName.text = user.username
// TODO Display avatar
}
}
})
return cell
}
func collectionView(collectionView : UICollectionView,86)
return cellSize
}
您可以在cellForItemAtIndexPath函数中动态设置单元格的框架,因此如果忽略sizeForItemAtIndexPath函数,您可以根据标签自定义高度.通过自定义大小,您可能需要查看集合视图布局流程,但希望这可以指向正确的方向.它可能看起来像这样：
class CollectionViewController: UICollectionViewController,UICollectionViewDelegate,UICollectionViewDataSource,UICollectionViewDelegateFlowLayout {
var array = ["a","as","asd","asdf","asdfg","asdfgh","asdfghjk","asdfghjklas","asdfghjkl","asdghjklkjhgfdsa"]
var heights = [10.0,20.0,30.0,40.0,50.0,60.0,70.0,80.0,90.0,100.0,110.0] as [CGFloat]
override func viewDidLoad() {
super.viewDidLoad()
}
override func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
return 1
}
override func collectionView(collectionView: UICollectionView,numberOfItemsInSection section: Int) -> Int {
return array.count
}
override func collectionView(collectionView: UICollectionView,cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("CellID",forIndexPath: indexPath) as Cell
cell.textLabel.text = array[indexPath.row]
cell.textLabel.sizeToFit()
// Customize cell height
cell.frame = CGRectMake(cell.frame.origin.x,cell.frame.origin.y,cell.frame.size.width,heights[indexPath.row])
return cell
}
func collectionView(collectionView: UICollectionView,layout collectionViewLayout: UICollectionViewLayout,sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
return CGSizeMake(64,64)
}
}
这给了动态高度
