Iphone SDWebImage始终从URL加载占位符图像，而不是图像

嗯,使用SDWeb镜像

这些是我的代码：

        UIImageView *sellerImage = [[UIImageView alloc]init];            
[sellerImage setImageWithURL:[NSURL URLWithString:[NSString stringWithFormat:productPicture]]
                        placeholderImage:[UIImage imageNamed:@"placeholder.png"]];

但它总是只加载占位符图像，而不是URL中的图像， 我尝试使用块来确定它是否加载了图像，并进入成功块，这意味着SDWebImage可以从URL加载图像，但不会更改占位符图像

以下是我尝试使用块时的代码：

            [sellerImage setImageWithURL:[NSURL URLWithString:[NSString stringWithFormat:productPicture]]
                placeholderImage:[UIImage imageNamed:@"placeholder.png"]
                         success:^(UIImage *image, BOOL cached) 
        {
            NSLog(@"success Block");
        }
                         failure:^(NSError *error) 
        {
            NSLog(@"failure Block");
        }];

正如我所说，它总是进入成功块，这意味着它可以从URL加载图像，但不会更改占位符图像

这是我问题的一个屏幕

尝试以下方法

UIImageView *sellerImage = [[UIImageView alloc]init];            
[sellerImage setImageWithURL:[NSURL URLWithString:[NSString stringWithFormat:
[productPicture stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]]]
placeholderImage:[UIImage imageNamed:@"placeholder.png"]];

[sellerImage setImageWithURL:[NSURL URLWithString:[productPicture stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]]
                placeholderImage:[UIImage imageNamed:@"placeholder.png"]
                         success:^(UIImage *image, BOOL cached) 
        {
            dispatch_async(dispatch_get_main_queue(), ^{
                sellerImage.image = image;
            });
            NSLog(@"success Block");
        }
                         failure:^(NSError *error) 
        {
            NSLog(@"failure Block");
        }];

也可以尝试以下方法

UIImageView *sellerImage = [[UIImageView alloc]init];            
[sellerImage setImageWithURL:[NSURL URLWithString:[NSString stringWithFormat:
[productPicture stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]]]
placeholderImage:[UIImage imageNamed:@"placeholder.png"]];

[sellerImage setImageWithURL:[NSURL URLWithString:[productPicture stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]]
                placeholderImage:[UIImage imageNamed:@"placeholder.png"]
                         success:^(UIImage *image, BOOL cached) 
        {
            dispatch_async(dispatch_get_main_queue(), ^{
                sellerImage.image = image;
            });
            NSLog(@"success Block");
        }
                         failure:^(NSError *error) 
        {
            NSLog(@"failure Block");
        }];

---

正确分配占位符图像。。我的问题是错误的图像扩展彼此不匹配，即占位符.jpeg和palceholder@2x.jpg

使用未声明的标识符调度\u get\u main\u队列已修复。你可以再次检查。检查此链接。