如何使用objective c从json获取collectionview单元格中的图像

Question

self->SCImageArr = [[NSMutableArray alloc]init];
            self->SCLabelArr = [[NSMutableArray alloc]init];

            NSDictionary *SCDic = [maindic objectForKey:@"specialcategories"];
            for (NSDictionary *SCDictionary in SCDic){
                NSString *strimage = [SCDictionary objectForKey:@"image"];
                [self->SCImageArr addObject:strimage];
                NSLog(@"SCImage :%@", strimage);  
                NSString *strname = [SCDictionary objectForKey:@"text"];
                [self->SCLabelArr addObject:strname];
                NSLog(@"SClabelname :%@", strname);
            } 
            [self.specialCategoriesCollectionView reloadData];

我的手机密码在这里

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{

    static NSString *CellIndentifer = @"Cell";
    SpecialCategoriesCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:CellIndentifer forIndexPath:indexPath];

    cell.categoriesImages.image = [UIImage imageWithData:SCImageArr];
    cell.categoriesNameLabel.text = self.specialCategoriesLabel[indexPath.row];

    return cell;
}

如何使用objective c从json中获取collectionview单元格中的图像？

Answer 1

你应该这样做：

 dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
    NSURL* url = [NSURL URLWithString:SCImageArr[indexPath.row]];
    NSData* data = [NSData dataWithContentsOfURL:url];

    UIImage* image = [UIImage imageWithData:data];

    dispatch_async(dispatch_get_main_queue(), ^{
        cell.categoriesImages.image = image;
    });
});

另外：它与问题无关，但不要给变量大写名称