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建立UIScrollView和UITableView的ViewController

1. 创建UIViewController类

首先，我们需要创建一个UIViewController类，并将其设置为UIScrollView和UITableView的代理。

#import 
   
      @protocol ICTableViewDelegate  -(void) cellImageDidLoad:(NSIndexPath *)indexPath image:(NSMutableArray *)imageArray;  @end  @interface ICTableViewController : UIViewController 
    
       @property (nonatomic, strong) id 
     
       delegate;  @property (nonatomic, strong):UITableView *tableView;  @property (nonatomic, strong) NSMutableArray *tableDataArray;  @end
     
    
   

2. 实现图片缓存的逻辑

我们需要在.loadCellImage方法中实现图片缓存和加载的逻辑。这将确保图片能够在视图中展示，同时避免重复请求

-(void) loadCellImage  {      NSArray *indexPathsForLoad = [self.tableView indexPathsForVisibleRows];      for (NSIndexPath *item in indexPathsForLoad) {          NSInteger rowNumberForCell = item.row;          if (rowNumberForCell >= [self.tableDataArray count]) {              return;          }          NSString *imageStr = self.tableDataArray[rowNumberForCell][@"photoFileUrl"];          if ([imageStr length] == 0) {              continue;          }          NSArray *photoUrl = [imageStr componentsSeparatedByString:MULTI_FILES_SEPARATOR];          for (NSInteger i = 0; i < photoUrl.count; i++) {              NSString *url = [photoUrl[i] stringByAppendingString:@".temp"];              NSString *imageDataPath = [NSHomeDirectory() stringByAppendingPathComponent:[                  @"Library/Caches/" stringByAppendingPathComponent:url              ]];              NSData *imageData = [NSData dataWithContentsOfFile:imageDataPath];              if (imageData) {                  UIImage *image = [UIImage imageWithData:imageData];                  if (!image) {                      continue;                  }                  UIImage *thumbImg = [FileTransferHelp thumbnailWithImage:image size:(CGSizeMake(60, 40))];                  if (thumbImg) {                      //设置图片到相应的控件中                      [photoBtn.imgView setImage:thumbImg];                      [cell.contentView addSubview:photoBtn];                  }              }          }      }  }

3. 子类化UIViewController并实现代理方法

在子类化UIViewController中，设置单元格内容并实现ICTableViewDelegate代理方法

@interface CustomPhotoTableViewCell : UITableViewCell  @property (nonatomic, strong) IBOutlet UIButton *photoBtn;  @property (nonatomic, strong) UILabel *urlLabel;  @property (nonatomic, strong) UIImageView *imgView;  @end  @interface CustomPhotoTableViewController : UIViewController 
   
      @property (nonatomic, strong) UITableView *tableView;  @property (nonatomic, strong) NSMutableArray *tableDataArray;  @end  @implementation CustomPhotoTableViewController  -(UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath  {      CustomPhotoTableViewCell *cell = (CustomPhotoTableViewCell *)[tableView dequeueReusableCellWithIdentifier:          [UITableViewCell 蒂PropertyValue:nil]];      if (!cell) {          [tableView dequeueReusableCellWithIdentifier:@"CustomPhotoTableViewCell"];      }      NSString *imageName = [url stringByAppendingString:@".temp"];      NSString *imageDataPath = [NSHomeDirectory() stringByAppendingPathComponent:[          @"Library/Caches/"          stringByAppendingPathComponent:imageName      ]];      UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfFile:imageDataPath]];      UIImage *thumbImg = [FileTransferHelp thumbnailWithImage:image size:(CGSizeMake(60, 40))];      if (thumbImg) {          [cell.imgView setImage:thumbImg];      } else {          [cell.imgView setImage:[UIImage imageNamed:@"placeholder"]];      }      [cell.photoBtn/fileFullName setText:url];      return cell;  }  -(void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath  {      // 单元格点击事件处理  }  - (void) cellImageDidLoad:(NSIndexPath *)indexPath image:(NSMutableArray *)imageArray  {      CustomPhotoTableViewCell *cell = (CustomPhotoTableViewCell *)[tableView cellForRowAtIndexPath:indexPath];      if (imageArray.count > 0) {          for (NSInteger i = 0; i < imageArray.count; i++) {              if (is_iOS8_or_later) {                  CustomPhotoBtn *photoBtn = (CustomPhotoBtn *)[cell.contentView viewWithTag:(i + 1) * 10];                  if (photoBtn) {                      UIImage *thumbImg = [FileTransferHelp thumbnailWithImage:(UIImage *)imageArray[i] size:(CGSizeMake(60, 40))];                      [photoBtn.imgView setImage:thumbImg];                      [cell.contentView addSubview:photoBtn];                  } else {                      [tableView beginUpdates];                      [cell(Layout setFrame:cell(Layout).frame);                      [tableView endUpdates];                  }              } else {                  CustomPhotoBtn *photoBtn = (CustomPhotoBtn *)[cell.contentView viewWithTag:(i + 1) * 10];                  if (photoBtn) {                      UIImage *thumbImg = [FileTransferHelp thumbnailWithImage:(UIImage *)imageArray[i] size:(CGSizeMake(60, 40))];                      [photoBtn.imgView setImage:thumbImg];                      [cell.contentView addSubview:photoBtn];                  } else {                      [tableView beginUpdates];                      [cell(Layout setFrame:cell(Layout).frame);                      [tableView endUpdates];                  }              }          }      }  }
   

4. 设置单元格内容

在cellForRowAtIndexPath中设置单元格内容

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"CustomPhotoTableViewCell"];  if (!cell) {      cell = [tableView dequeueReusableCellWithIdentifier:@"CustomPhotoTableViewCell"];  }  CustomPhotoBtn *photoBtn = [CustomPhotoBtn customPhotoBtn];  photoBtn.fileFullName.textColor = [UIColor blueColor];  NSString *imageName = [url stringByAppendingString:@".temp"];  NSString *imageDataPath = [NSHomeDirectory() stringByAppendingPathComponent:[      @"Library/Caches/"      stringByAppendingString:imageName  ]];  NSData *imageData = [NSData dataWithContentsOfFile:imageDataPath];  if (imageData) {      UIImage *image = [UIImage imageWithData:imageData];      if (image) {          UIImage *thumbImg = [FileTransferHelp thumbnailWithImage:image size:(CGSizeMake(60, 40))];          if (thumbImg) {              [photoBtn.imgView setImage:thumbImg];              [cell.contentView addSubview:photoBtn];          } else {              [cell.imgView setImage:[UIImage imageNamed:@"placeholder"]];          }      } else {          [cell.imgView setImage:[UIImage imageNamed:@"placeholder"]];      }  } else {      [cell.imgView setImage:[UIImage imageNamed:@"placeholder"]];  }[cell.contentView addSubview:photoBtn];  return cell;

5. 最后运行代码

确保项目中正确引入必要的头文件，并确保所有必要的控件已经在xib文件中定义。运行项目测试表格是否正确加载图片，如果图片缓存存在，直接显示；否则按需求加载和缓存。

通过这些步骤，您可以轻松实现带有UIScrollView和UITableView的缓存图片加载功能，同时确保性能优化和用户体验良好。