显示不消耗资源的时间线

Question

null

取照片：

if(feedArray.count > 0){
  for(NSString *person in feedArray){
  int count = [[Globals global] getMiscPicsCountForUser:person];
  for(int i = 1; i < count; i++){
    [[Globals global] getMiscPicForUser:person :i withFetchedPicture:^(WKImage *image) {
      if(image){
        [self.thisPersonsTimelineObjects  addObject:image];
        //[self createTimelineViewForImage:image];
        NSLog(@"person: %@ -- count:%i -- temp array count:%lu -- i:%i", person, count, self.thisPersonsTimelineObjects.count ,i);
        if(self.thisPersonsTimelineObjects.count == count - 1){
          [self sortTimelineByDate];
        }
      }
    }];
  }
}

}

-(void)createTimelineViewForImage :(WKImage *)image {
  dispatch_async(dispatch_queue_create("timeline", NULL), ^{
    dispatch_async(dispatch_get_main_queue(), ^{
      UIStoryboard *storyboard = [UIStoryboard storyboardWithName:[[NSBundle mainBundle].infoDictionary objectForKey:@"UIMainStoryboardFile"] bundle:[NSBundle mainBundle]];
      WKTimelineViewsViewController *view = [storyboard instantiateViewControllerWithIdentifier:@"WKTimelineViewViewController"];
      [view initWithImage:image andParentController:self];
      view.view.frame = CGRectMake(view.view.frame.origin.x,
                                   view.view.frame.origin.y,
                                   view.view.frame.size.width * 0.95,
                                   view.view.frame.size.height * 0.95);
      [self.thisPersonsTimelineViews addObject:view];
      [self.tableView reloadData];
    });
  });

}
-(void)sortTimelineByDate {
  if(self.thisPersonsTimelineObjects.count > 0){
    NSMutableArray *dateArray = [NSMutableArray array];
    for(WKImage *view in self.thisPersonsTimelineObjects){
      [dateArray addObject:[view timeStamp]];
    }
    NSMutableArray *tempArray = [NSMutableArray array];
    NSSortDescriptor *descriptor = [[NSSortDescriptor alloc] initWithKey:@"self" ascending:NO];
    NSArray *descriptors = [NSArray arrayWithObject:descriptor];
    NSArray *reverseOrder = [dateArray sortedArrayUsingDescriptors:descriptors];

    for(int i = 0; i < reverseOrder.count; i++){
      NSDate *date = reverseOrder[i];
      for(int j = 0; j < self.thisPersonsTimelineObjects.count; j++){
        NSDate *timestamp = [self.thisPersonsTimelineObjects[j] timeStamp];
        if(date == timestamp){
          [tempArray addObject:self.thisPersonsTimelineObjects[j]];
        }
      }
    }
    self.thisPersonsTimelineObjects = [NSMutableArray arrayWithArray:tempArray];
    [self.thisPersonsTimelineViews removeAllObjects];
    for(WKImage *image in self.thisPersonsTimelineObjects){
      [self createTimelineViewForImage:image];
    }
  }
}

Answer 1

您遇到了一个问题，因为所有的图像都是预先获取的。相反，你想要做的是在用户滚动时获取所需的图像，然后在下载时缓存它们（这是Instagram和Facebook所做的）。

首先，我建议将SDWebImage集成到您的项目中，因为它使所有这些都变得更容易。

接下来，您可以集成以下逻辑：

null

这里有一个例子：

1和2（在数据源中）：

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell"];
    if (!cell) {

        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"Cell"];

    }

    PhotoObject *object = [self objects][[indexPath row]];
    [[cell imageView] sd_setImageWithURL:[object photoURL]];

    return cell;

}

3：（表格单元格内）

-(void)prepareForReuse {

    [super prepareForReuse];

    [[self imageView] sd_cancelCurrentImageLoad];
    [[self imageView] setImage:nil];

}