ios - 从 YouTube JSON 数据 Objective C 获取缩略图

Question

我想在自定义单元格中显示 YouTube 视频的缩略图。我有 JSON 链接，但不确定如何获取实际图像？我的代码在下面!

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

*)indexPath
{
    static NSString *CellIdentifier = @"RemedyYouTubeTableViewCell";
    RemedyYouTubeTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil) {
        NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"RemedyYouTubeTableViewCell" owner:nil options:nil];
        for(id obj in topLevelObjects) {
            if([obj isKindOfClass:[UITableViewCell class]]) {
                cell = obj;
                break;
            }
        }


    }

    // Configure the cell...

   // cell.videoThumbnail.image = [UIImage imageNamed:[thumbNailArray objectAtIndex:indexPath.row]];

    NSArray *subArray = [subDict objectForKey:@"items"];
    if ([subArray count]) {
        for (NSDictionary *dictItem in subArray) {
            cell.titleLabel.text = [dictItem objectForKey:@"title"];

            NSNumber *totalSeconds = [dictItem objectForKey:@"duration"];
            int *minutes = totalSeconds.intValue/60;
            int *seconds = totalSeconds.intValue%60;
            NSString *finalDuration =[NSString stringWithFormat:@"%im %is", minutes,seconds];
            cell.durationLabel.text = finalDuration;


            NSString *separatorString = @"T";
            NSString *firstUploadString = [dictItem objectForKey:@"uploaded"];
            NSString *uploadString = [firstUploadString componentsSeparatedByString:separatorString].firstObject;
            cell.dateUploadLabel.text = uploadString;

            NSString *viewCount = [NSString stringWithFormat:@"%@",[dictItem objectForKey:@"viewCount"]];
            cell.viewsLabel.text = viewCount;

            NSString *thumbnailURL = [dictItem objectForKey:@"thumbnail"];

        }
    }



    return cell;
}

其他一切都很好，但我该如何处理缩略图 URL？谢谢!

我的代码现在看起来像这样......

NSString *viewCount = [NSString stringWithFormat:@"%@",[dictItem objectForKey:@"viewCount"]];
            cell.viewsLabel.text = viewCount;

            NSDictionary *thumbnailDict = [dictItem objectForKey:@"thumbnail"];
            //NSString *thumbnailURl = [thumbnailDict objectForKey:@"sqDefault"];
            //UIImage *thumbNailImage = nil;

            dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

                NSString *thumbnailURL = [thumbnailDict objectForKey:@"sqDefault"];
                NSLog(thumbnailURL);
                NSURL *url = [NSURL URLWithString:thumbnailURL];
                NSData *imageData = [NSData dataWithContentsOfURL:url];
                UIImage *thumbNailImage = [UIImage imageWithData:imageData];

                dispatch_async(dispatch_get_main_queue(), ^{
                    // Here in main thread set image to your cell imageView.
                    // e.g.
                    [cell.videoThumbnail setImage:thumbNailImage];
                });
            });





        };
    }



    return cell;
}

Answer 1

您只需要从该 url 获取 NSData。确保 url 有效且可用。

@try {

    UIImage *thumbNailImage = nil;

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

        NSString *thumbnailURL = [dictItem objectForKey:@"thumbnail"];
        NSURL *url = [NSURL URLWithString:thumbnailURL];
        NSData *imageData = [NSData dataWithContentsOfURL:url];
        UIImage *thumbNailImage = [UIImage imageWithData:imageData];

        dispatch_async(dispatch_get_main_queue(), ^{
            // Here in main thread set image to your cell imageView.
            // e.g.
            [cell.imageView setImage:thumbNailImage];
        });
    });

}
@catch (NSException *exception) {
    NSLog(@"Exception :%@",exception.debugDescription);
}