处理相册分批加载：每次36

SwiftProject/SwiftProject/Project/View/Album/CCSpaceAlbumFliterPopView/CCSpaceAlbumFilterPopView2.swift

@@ -133,15 +133,14 @@ class CCSpaceAlbumFilterPopView2: UIView {
     var selectedVideoHandler: ((URL,PHAsset) -> Void)?
     var selectedFileType:SelectedFileType = .all {
         didSet{
-            filterOffset = 0
             reloadData()
         }
     }
     
     var dataSource:[CCSpaceAlbumFliterModel] = []
-    var filterOffset = 0//筛选内容的当前下标
+    let filterLimit = 36//一次性获取的内容数量
-    let filterLimit = 80//一次性获取的内容数量
+    var isLoadingMoreData = false//标识是否正在加载更多的数据
-    
+    var shouldLoadDataCount = 0//标识本次总的加载数据是多少条
     
     lazy var backView: UIView = {
         let imageView = UIView(frame: CGRectMake(0, KScreenHeight + 10 , KScreenWidth, Back_Height))
@@ -333,11 +332,13 @@ class CCSpaceAlbumFilterPopView2: UIView {
     func reloadData(){
         print("重新装载数据。。。")
         self.dataSource.removeAll()
-        loadMoreData(offset: filterOffset)
+        self.listCollectView.reloadData()
+        loadMoreData(offset: 0)
     }
     
     func loadMoreData(offset:Int) {
-        
+        print("loadMoreData。。。")
+        isLoadingMoreData = true
         let fetchResult_collection = PHAssetCollection.fetchAssetCollections(with: PHAssetCollectionType.smartAlbum, subtype: PHAssetCollectionSubtype.any, options: nil);
         //筛选空间相册
         var spatialAC:PHAssetCollection?
@@ -361,9 +362,11 @@ class CCSpaceAlbumFilterPopView2: UIView {
             }
             let fetchResult_asset = PHAsset.fetchAssets(in: sac, options: fetchOptions)
             guard offset < fetchResult_asset.count else {//确保筛选有数据
+                self.isLoadingMoreData = false
                 return
             }
             
+            shouldLoadDataCount = min(fetchResult_asset.count - offset, filterLimit)
             var count = 0
             for i in offset ..< fetchResult_asset.count {
                 let asset = fetchResult_asset.object(at: i)
@@ -374,6 +377,9 @@ class CCSpaceAlbumFilterPopView2: UIView {
                 }
             }
         }
+        else {
+            isLoadingMoreData = false
+        }
         
         self.listCollectView.reloadData()
     }
@@ -384,7 +390,6 @@ class CCSpaceAlbumFilterPopView2: UIView {
         let requestOptions = PHImageRequestOptions()
         requestOptions.isSynchronous = false//设置成同步回调
         requestOptions.deliveryMode = .highQualityFormat
-        print("asset mediatype:\(asset.mediaType)")
         PHImageManager.default().requestImageDataAndOrientation(for: asset, options: requestOptions) {[weak self] data, dataUTI, imagePropertyOrientation, info in
             if let hasData = data {
                 let photoImage:UIImage = UIImage(data: hasData)!
@@ -392,6 +397,11 @@ class CCSpaceAlbumFilterPopView2: UIView {
                 let model = CCSpaceAlbumFliterModel.initWithAssetType(assetType: AssetType.init(rawValue: asset.mediaType.rawValue-1)!, asset: asset,image:photoImage, localIdentifier: asset.localIdentifier)
                 self?.dataSource.append(model)
                 self?.listReloadData()
+                self?.shouldLoadDataCount = (self?.shouldLoadDataCount ?? 0) - 1
+                if (self?.shouldLoadDataCount ?? 0) <= 0 {
+                    self?.isLoadingMoreData = false
+                }
+                
             }
             
         }
@@ -409,6 +419,26 @@ extension CCSpaceAlbumFilterPopView2:UICollectionViewDataSource, UICollectionVie
         return self.dataSource.count
     }
     
+    
+    func scrollViewDidScroll(_ scrollView: UIScrollView) {
+        let contentOffset = scrollView.contentOffset
+        let contentSize = scrollView.contentSize
+        let frameSize = scrollView.frame.size
+
+        // 判断是否滑动到底部
+        if contentOffset.y + frameSize.height >= contentSize.height {
+            // 此时 collectionView 即将滑动到底部
+            guard self.isLoadingMoreData == false else {
+                print("正在加载中，等加载完毕在装载更多。。。。")
+                return
+            }
+            self.loadMoreData(offset: self.dataSource.count)
+        }
+    }
+    
+  
+    
+
     func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
         let cell = collectionView.dequeueReusableCell(withReuseIdentifier: AlbumIdentifierCell, for: indexPath) as! CCSpaceAlbumFliterCollectionCell