dry18813 2012-04-04 10:04
浏览 1284

在iOS上从网页请求BLOB

I have a BLOB image stored in a MySQL database, of which I would like to use in my iOS Application. I have created a PHP file to retrieve the BLOB from the database, but I am unsure of what I need to do to get the BLOB into my app.

Please can you give me an example, or point me in the direction of doing so?

Thanks in advanced!

  • 写回答

1条回答 默认 最新

  • douren5490 2012-04-04 11:22
    关注

    Use ASIIHTTPRequest to request the BLOB data from that PHP page.

    With the BLOB data, convert it to a UIImage.

    - (void) getBlobData:(NSURL *) url {
        NSURL *url = [NSURL URLWithString:url];
        __block ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
        [request setCompletionBlock:^{
           NSData *blobData = [request responseData];
           UIImage *blobImage = [UIImage imageWithData:blobData] retain];
           [someImageView performSelectorOnMainThread:@selector(setImage:)
           withObject:blobImage 
           waitUntilDone:YES];
        }];
    
        [request setFailedBlock:^{
          NSError *error = [request error];
        }];
        [request startAsynchronous];
    }
    

    Alternatively, you could use Grand Central Dispatch (GCD) to send a request to the web-page in order to receive the blob:

    - (void) getBlobData:(NSURL *) url {
    
        dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0ul); 
        dispatch_async(queue, ^{  
            NSData *blobData = [NSData dataWithContentsOfURL:url];       
            UIImage *blobImage = [UIImage imageWithData:blobData];
            dispatch_sync(dispatch_get_main_queue(), ^{
                 [someImageView setImage:blobImage];
             });
         }); 
    }
    
    评论

报告相同问题?

悬赏问题

  • ¥15 flask项目,怎么使用AJAX传数据库数据到echarts图表的data里,实现异步加载数据。
  • ¥15 本题的答案是不是有问题
  • ¥15 关于#r语言#的问题:(svydesign)为什么在一个大的数据集中抽取了一个小数据集
  • ¥15 C++使用Gunplot
  • ¥15 这个电路是如何实现路灯控制器的,原理是什么,怎么求解灯亮起后熄灭的时间如图?
  • ¥15 matlab数字图像处理频率域滤波
  • ¥15 在abaqus做了二维正交切削模型,给刀具添加了超声振动条件后输出切削力为什么比普通切削增大这么多
  • ¥15 ELGamal和paillier计算效率谁快?
  • ¥15 蓝桥杯单片机第十三届第一场,整点继电器吸合,5s后断开出现了问题
  • ¥15 file converter 转换格式失败 报错 Error marking filters as finished,如何解决?