优化照片预览时的体验，先展示缩略图，再展示大图...

TZImagePickerController/TZImagePickerController/TZAssetCell.m

@@ -28,7 +28,7 @@
 
 - (void)setModel:(TZAssetModel *)model {
     _model = model;
-    [[TZImageManager manager] getPhotoWithAsset:model.asset photoWidth:self.width completion:^(UIImage *photo, NSDictionary *info) {
+    [[TZImageManager manager] getPhotoWithAsset:model.asset photoWidth:self.width completion:^(UIImage *photo, NSDictionary *info, BOOL isDegraded) {
         self.imageView.image = photo;
     }];
     self.selectPhotoButton.selected = model.isSelected;

TZImagePickerController/TZImagePickerController/TZImageManager.h

@@ -27,8 +27,8 @@
 
 /// Get photo 获得照片
 - (void)getPostImageWithAlbumModel:(TZAlbumModel *)model completion:(void (^)(UIImage *postImage))completion;
-- (void)getPhotoWithAsset:(id)asset completion:(void (^)(UIImage *photo,NSDictionary *info))completion;
-- (void)getPhotoWithAsset:(id)asset photoWidth:(CGFloat)photoWidth completion:(void (^)(UIImage *photo,NSDictionary *info))completion;
+- (void)getPhotoWithAsset:(id)asset completion:(void (^)(UIImage *photo,NSDictionary *info,BOOL isDegraded))completion;
+- (void)getPhotoWithAsset:(id)asset photoWidth:(CGFloat)photoWidth completion:(void (^)(UIImage *photo,NSDictionary *info,BOOL isDegraded))completion;
 
 /// Get video 获得视频
 - (void)getVideoWithAsset:(id)asset completion:(void (^)(AVPlayerItem * playerItem, NSDictionary * info))completion;

TZImagePickerController/TZImagePickerController/TZImageManager.m

@@ -228,11 +228,11 @@
 #pragma mark - Get Photo
 
 /// Get photo 获得照片本身
-- (void)getPhotoWithAsset:(id)asset completion:(void (^)(UIImage *, NSDictionary *))completion {
+- (void)getPhotoWithAsset:(id)asset completion:(void (^)(UIImage *, NSDictionary *, BOOL isDegraded))completion {
     [self getPhotoWithAsset:asset photoWidth:[UIScreen mainScreen].bounds.size.width completion:completion];
 }
 
-- (void)getPhotoWithAsset:(id)asset photoWidth:(CGFloat)photoWidth completion:(void (^)(UIImage *, NSDictionary *))completion {
+- (void)getPhotoWithAsset:(id)asset photoWidth:(CGFloat)photoWidth completion:(void (^)(UIImage *, NSDictionary *, BOOL isDegraded))completion {
     if ([asset isKindOfClass:[PHAsset class]]) {
         PHAsset *phAsset = (PHAsset *)asset;
         CGFloat aspectRatio = phAsset.pixelWidth / (CGFloat)phAsset.pixelHeight;
@@ -240,9 +240,9 @@
         CGFloat pixelWidth = photoWidth * multiple;
         CGFloat pixelHeight = pixelWidth / aspectRatio;
         [[PHImageManager defaultManager] requestImageForAsset:asset targetSize:CGSizeMake(pixelWidth, pixelHeight) contentMode:PHImageContentModeAspectFit options:nil resultHandler:^(UIImage * _Nullable result, NSDictionary * _Nullable info) {
-            BOOL downloadFinined = (![[info objectForKey:PHImageCancelledKey] boolValue] && ![info objectForKey:PHImageErrorKey] && ![[info objectForKey:PHImageResultIsDegradedKey] boolValue]);
+            BOOL downloadFinined = (![[info objectForKey:PHImageCancelledKey] boolValue] && ![info objectForKey:PHImageErrorKey]);
             if (downloadFinined) {
-                if (completion) completion(result,info);
+                if (completion) completion(result,info,[[info objectForKey:PHImageResultIsDegradedKey] boolValue]);
             }
         }];
     } else if ([asset isKindOfClass:[ALAsset class]]) {
@@ -255,13 +255,13 @@
             imageRef = alAsset.thumbnail;
         }
         UIImage *image = [UIImage imageWithCGImage:imageRef scale:1.0 orientation:(UIImageOrientation)[assetRep orientation]];
-        if (completion) completion(image,nil);
+        if (completion) completion(image,nil,NO);
     }
 }
 
 - (void)getPostImageWithAlbumModel:(TZAlbumModel *)model completion:(void (^)(UIImage *))completion {
     if (iOS8Later) {
-        [[TZImageManager manager] getPhotoWithAsset:[model.result lastObject] photoWidth:80 completion:^(UIImage *photo, NSDictionary *info) {
+        [[TZImageManager manager] getPhotoWithAsset:[model.result lastObject] photoWidth:80 completion:^(UIImage *photo, NSDictionary *info, BOOL isDegraded) {
             if (completion) completion(photo);
         }];
     } else {

TZImagePickerController/TZImagePickerController/TZImagePickerController.m

@@ -38,7 +38,7 @@
         self.navigationBar.tintColor = [UIColor whiteColor];
         self.automaticallyAdjustsScrollViewInsets = NO;
     }
-    
+        
     UIBarButtonItem *barItem;
     if (iOS9Later) {
         barItem = [UIBarButtonItem appearanceWhenContainedInInstancesOfClasses:@[[TZImagePickerController class]]];

TZImagePickerController/TZImagePickerController/TZPhotoPickerController.m

@@ -195,7 +195,8 @@
     
     for (NSInteger i = 0; i < _selectedPhotoArr.count; i++) {
         TZAssetModel *model = _selectedPhotoArr[i];
-        [[TZImageManager manager] getPhotoWithAsset:model.asset completion:^(UIImage *photo, NSDictionary *info) {
+        [[TZImageManager manager] getPhotoWithAsset:model.asset completion:^(UIImage *photo, NSDictionary *info, BOOL isDegraded) {
+            if (isDegraded) return;
             if (photo) [photos addObject:photo];
             if (info) [infoArr addObject:info];
             if (_isSelectOriginalPhoto) [assets addObject:model.asset];

TZImagePickerController/TZImagePickerController/TZPhotoPreviewCell.m

@@ -63,7 +63,7 @@
 - (void)setModel:(TZAssetModel *)model {
     _model = model;
     [_scrollView setZoomScale:1.0 animated:NO];
-    [[TZImageManager manager] getPhotoWithAsset:model.asset completion:^(UIImage *photo, NSDictionary *info) {
+    [[TZImageManager manager] getPhotoWithAsset:model.asset completion:^(UIImage *photo, NSDictionary *info, BOOL isDegraded) {
         self.imageView.image = photo;
         [self resizeSubviews];
     }];

TZImagePickerController/TZImagePickerController/TZVideoPlayerController.m

@@ -35,7 +35,7 @@
 }
 
 - (void)configMoviePlayer {
-    [[TZImageManager manager] getPhotoWithAsset:_model.asset completion:^(UIImage *photo, NSDictionary *info) {
+    [[TZImageManager manager] getPhotoWithAsset:_model.asset completion:^(UIImage *photo, NSDictionary *info, BOOL isDegraded) {
         _cover = photo;
     }];
     [[TZImageManager manager] getVideoWithAsset:_model.asset completion:^(AVPlayerItem *playerItem, NSDictionary *info) {