在我的 UICollecitonView 中，我使用 API 附加数据

self.DataTableCollectionView.reloadData()

但是随着我收藏中的数据越来越多，它的滚动变得粗糙，加载一些页面后，向上或向下滚动变得非常困难。它卡住了。

最终，当我尝试一次加载 1000 行时，滚动工作顺利，但当我尝试使用 API 一次分页和加载 50 行时，滚动变得困难。

谁能帮我解决这个问题？

我无法弄清楚哪里出了问题？ self.DataTableCollectionView.reloadData() 对此负责吗？

这是在滚动条上加载数据的代码:

func scrollViewDidScroll(scrollView: UIScrollView) {

     let offsetY = scrollView.contentOffset.y
     let contentHeight = scrollView.contentSize.height

     if(offsetY > (contentHeight - scrollView.frame.size.height)){              

         let seconds = 3.0
         let delay = seconds * Double(NSEC_PER_SEC)
         let dispatchTime = dispatch_time(DISPATCH_TIME_NOW, Int64(delay))

         self.loadMoreData()
         dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), {
             self.DataTableCollectionView.reloadData()

         })                
      }        

}

==========

我正在重用这些细胞

self.DataTableCollectionView .registerNib(UINib(nibName: "DCollectionViewCell", bundle: nil), forCellWithReuseIdentifier: dCellIdentifier)
self.DataTableCollectionView .registerNib(UINib(nibName: "CCollectionViewCell", bundle: nil), forCellWithReuseIdentifier: cCellIdentifier) 

为了重用:

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {

let dCell : DCollectionViewCell = collectionView .dequeueReusableCellWithReuseIdentifier(dCellIdentifier, forIndexPath: indexPath) as! DCollectionViewCell

let cCell : ContentCollectionViewCell = collectionView .dequeueReusableCellWithReuseIdentifier(cCellIdentifier, forIndexPath: indexPath) as! CCollectionViewCell       
}

=========

添加更具体的代码:

现在我更新了滚动功能，

func scrollViewDidScroll(scrollView: UIScrollView) {
    let offsetY = scrollView.contentOffset.y
    let contentHeight = scrollView.contentSize.height
    if(offsetY > (contentHeight - scrollView.frame.size.height)){
       var returnTableData = NSMutableArray()

       self.InspectPageId = self.InspectPageId+1
       self.dataSource.populateData(PageId:self.InspectPageId)
       returnTableData = self.dataSource.DTableDataArray

       if(returnTableData.count>0){
          for i in 0..<returnTableData.count {
             self.TableDataArray.addObject(returnTableData[i])
          }
       }
       self.NumberOfRows = self.TableDataArray.count

       dispatch_async(dispatch_get_main_queue(),{
          self.DataTableCollectionView.reloadData()
       })
   }
}

以下是手动创建 Collection View 的代码:

if indexPath.row == 0 {
//Here Header Cell is creating
                let dateCell : DateCollectionViewCell = collectionView .dequeueReusableCellWithReuseIdentifier(dateCellIdentifier, forIndexPath: indexPath) as! DateCollectionViewCell
                dateCell.dateLabel.font = UIFont(name:"HelveticaNeue", size: 12)
                dateCell.dateLabel.textColor = UIColor.blackColor()
                dateCell.dateLabel.textAlignment = .Left
                dateCell.dateLabel.text = UMIDDataArray[rowIndex-1] as? String
                dateCell.backgroundColor = UIColor.whiteColor()
                dateCell.layer.shouldRasterize = true
                dateCell.layer.rasterizationScale = UIScreen.mainScreen().scale
                return dateCell
            } else {
//Here Data Cell is Creating
                let contentCell : ContentCollectionViewCell = collectionView .dequeueReusableCellWithReuseIdentifier(contentCellIdentifier, forIndexPath: indexPath) as! ContentCollectionViewCell
                contentCell.contentLabel.font = UIFont(name:"HelveticaNeue", size: 12)
                contentCell.contentLabel.textColor = UIColor.blackColor()
                contentCell.contentLabel.textAlignment = .Left
                contentCell.bottomBorder.hidden  = false
                contentCell.layer.shouldRasterize = true
                contentCell.layer.rasterizationScale = UIScreen.mainScreen().scale

                let LensData:NSArray =  TableDataArray[rowIndex-1] as! NSArray
                let ColumnValue = LensData[colIndex-1] as? String
                contentCell.contentLabel.text = ColumnValue
                contentCell.backgroundColor = UIColor.whiteColor()

                return contentCell
            }

Following is the code which is use to take data from API:

//function of DataSource Class.
func populateData(PageId:Int){
var returnData = NSMutableArray()
let OtherColobjects = NSMutableArray()

let Urlpath = SetApiUrl()
let url: NSURL = NSURL(string: Urlpath)!
let urlRequest = NSURLRequest(URL: url)

let config = NSURLSessionConfiguration.defaultSessionConfiguration()
let session = NSURLSession(configuration: config)

let semaphore = dispatch_semaphore_create(0)
let task = session.dataTaskWithRequest(urlRequest) {
(data, response, error) in

guard error == nil else {
return
}

guard let responseData = data else {
return
}

do {
guard let Data = try NSJSONSerialization.JSONObjectWithData(responseData, options: []) as? [String: AnyObject] else {
return
}

for anItem in Data["result"]!["DATA"] as! [Dictionary<String, AnyObject>] {
let d1 = self.checkForNull(anItem["data1"]!)
let d2 = self.checkForNull(anItem["data2"]!)
let d3 = self.checkForNull(anItem["data3"]!)
let d4 = self.checkForNull(anItem["data4"]!)
...... // Total 20 Columns

let obj = [ d1, d2, d3, d4,.............,d20 ]

OtherColobjects.addObject(obj)
}
dispatch_semaphore_signal(semaphore)
} catch {
return
}
}
task.resume()

dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER)
self.NumberOfRows = returnData[0].count
self.DTableDataArray = returnData[1] as! NSMutableArray
}

最佳答案

在您的出队单元之后添加以下两行，

cell.layer.shouldRasterize = YES;
cell.layer.rasterizationScale = [UIScreen mainScreen].scale;

关于ios - UICollectionView 在重新加载数据时滚动不流畅，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/41058298/