我正在尝试将新数据附加到 Tableview，并且只为添加的新数据重新加载 Tableview。
我的应用程序一直崩溃给我这个错误：“尝试从第 0 部分删除第 19 行，它在更新前只包含 10 行”
一旦异步函数 contentQueryContinuous() 完成，我想重新加载这些行。
这是我的代码：
//Once User Scrolls all the way to bottom, beginContentBatchFetch() is called
func scrollViewDidScroll(_ scrollView: UIScrollView) {
let offsetY = scrollView.contentSize.height
let contentHeight = scrollView.contentSize.height
if offsetY > contentHeight - scrollView.frame.height {
beginContentBatchFetch()
}
}
//Content Batch Fetch looks up to 10 new elements, tries to append to current array's, and then reload's tableview only for those new elements
func beginContentBatchFetch() {
contentFetchMore = true
ProgressHUD.show()
let oldcount = contentObjectIdArray.count
var IndexPathsToReload = [IndexPath]()
var startIndex = Int()
var endIndex = Int()
DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
//Calls self.contentQueryContinous which adds new elements
self.contentQueryContinous()
let newElements = self.contentObjectIdArray.count - oldcount
startIndex = oldcount
endIndex = self.contentObjectIdArray.count
for index in startIndex..<endIndex {
let indexPath = IndexPath(row: index, section: 0)
IndexPathsToReload.append(indexPath)
}
if newElements > 0 {
self.MyTableView.reloadRows(at: IndexPathsToReload, with: .fade)
}
ProgressHUD.dismiss()
}
}
这是 contentQueryContinous()
func contentQueryContinous() {
if contentObjectIdArray.count != 0 {
contentSkip = contentObjectIdArray.count
let query = PFQuery(className: "ContentPost")
query.whereKey("Spot", equalTo: SpotText)
query.limit = 10
query.skip = contentSkip
query.addDescendingOrder("createdAt")
query.findObjectsInBackground(block: { (objects: [PFObject]?,error: Error?) in
if let objects = objects {
for object in objects {
let ProfileImageFile = object["ProfileImage"] as? PFFileObject
let urlString = ProfileImageFile?.url as! String
if let url = URL(string: urlString) {
let data = try? Data(contentsOf: url)
if let imageData = data {
self.contentPostProPicUrlArray.append(urlString as NSString)
self.contentPostProPicImageCache.setObject(UIImage(data: imageData)!, forKey: urlString as NSString)
}
}
if object["Post"] != nil && object["UserLikes"] != nil && object["Username"] != nil && object["UserTime"] != nil {
self.contentPostArray.append(object["Post"] as! String)
self.contentLikeArray.append(object["UserLikes"] as! Int)
self.contentUsernameArray.append(object["Username"] as! String)
self.contentTimeArray.append(object["UserTime"] as! String)
self.contentObjectIdArray.append(object.objectId!)
}
}
print(self.contentPostArray)
}
})
}
}