使用 Xcode 和 PHP 将图像上传到网络服务器

几个反应：

1. 如果您使用 AFNetworking，则创建这些类型的请求的过程会更简单，让您摆脱自己构建请求的杂草：

   AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
   manager.responseSerializer = [AFHTTPResponseSerializer serializer];
   [manager POST:[url absoluteString] parameters:nil constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
       [formData appendPartWithFileData:imageData name:fieldName fileName:[imagePath lastPathComponent] mimeType:[self mimeTypeForPath:imagePath]];
   } success:^(AFHTTPRequestOperation *operation, id responseObject) {
       NSString *string = [[NSString alloc] initWithData:responseObject encoding:NSUTF8StringEncoding];
       NSLog(@"Success: %@", string);
   } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
       NSLog(@"Error: %@", error);
   }];
   

2. 顺便说一下，我通常使用MobileCoreServices.framework在扩展的基础上获取mime类型，而不是硬编码它：

   - (NSString *)mimeTypeForPath:(NSString *)path
   {
       // get a mime type for an extension using MobileCoreServices.framework
       CFStringRef extension = (__bridge CFStringRef)[path pathExtension];
       CFStringRef UTI = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, extension, NULL);
       assert(UTI != NULL);
       NSString *mimetype = CFBridgingRelease(UTTypeCopyPreferredTagWithClass(UTI, kUTTagClassMIMEType));
       assert(mimetype != NULL);
       CFRelease(UTI);
       return mimetype;
   }
   

3. 我注意到您正在将图像检索到UIImage中，然后使用UIImageJPEGRepresentation来获取NSData。如果您愿意或必须这样做，请执行此操作，但我通常更喜欢发送原始数据，直接绕过通过UIImage的往返，这可能会引入图像降级和元数据丢失。相反，您可能希望直接获取NSData：

   NSString *imagePath = [[NSBundle mainBundle] pathForResource:@"mypic" ofType:@"png"]; // note, I'm going back to bundle, not grabbing `UIImage` from imageview
   NSData   *imageData = [NSData dataWithContentsOfFile:imagePath];
   

   如果你真的必须通过UIImage进行往返，那么你可能想要使用imageWithContentsOfFile而不是imageNamed，因为后者会不必要地缓存图像。

4. 如果您决定自己创建请求，这是我过去使用的例程：

   - (void)uploadFileAtPath:(NSString *)imagePath
                   forField:(NSString *)fieldName
                        URL:(NSURL*)url
                 parameters:(NSDictionary *)parameters
   {
       NSString *filename = [imagePath lastPathComponent];
       NSData *imageData = [NSData dataWithContentsOfFile:imagePath];
       NSMutableData *httpBody = [NSMutableData data];
       NSString *boundary = [self generateBoundaryString];
       NSString *mimetype = [self mimeTypeForPath:imagePath];
       // configure the request
       NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url];
       [request setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData];
       [request setHTTPShouldHandleCookies:NO];
       [request setTimeoutInterval:30];
       [request setHTTPMethod:@"POST"];
       // set content type
       NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary];
       [request setValue:contentType forHTTPHeaderField: @"Content-Type"];
       // add params (all params are strings)
       [parameters enumerateKeysAndObjectsUsingBlock:^(NSString *parameterKey, NSString *parameterValue, BOOL *stop) {
           [httpBody appendData:[[NSString stringWithFormat:@"--%@'r'n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
           [httpBody appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name='"%@'"'r'n'r'n", parameterKey] dataUsingEncoding:NSUTF8StringEncoding]];
           [httpBody appendData:[[NSString stringWithFormat:@"%@'r'n", parameterValue] dataUsingEncoding:NSUTF8StringEncoding]];
       }];
       // add image data
       if (imageData) {
           [httpBody appendData:[[NSString stringWithFormat:@"--%@'r'n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
           [httpBody appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name='"%@'"; filename='"%@'"'r'n", fieldName, filename] dataUsingEncoding:NSUTF8StringEncoding]];
           [httpBody appendData:[[NSString stringWithFormat:@"Content-Type: %@'r'n'r'n", mimetype] dataUsingEncoding:NSUTF8StringEncoding]];
           [httpBody appendData:imageData];
           [httpBody appendData:[@"'r'n" dataUsingEncoding:NSUTF8StringEncoding]];
       }
       [httpBody appendData:[[NSString stringWithFormat:@"--%@--'r'n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
       // setting the body of the post to the reqeust
       [request setHTTPBody:httpBody];
       [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
           if (connectionError)
           {
               NSLog(@"sendAsynchronousRequest error=%@", connectionError);
               return;
           }
           NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
           NSLog(@"Success: %@", string);
       }];
   }
   

   显然，如果您没有使用任何parameters（您似乎没有这样做），则可以为该参数传递nil。但关键是，如果需要，它支持其他参数。我还使用异步网络请求，因为永远不应该在主队列上发出同步网络请求。

   这使用 Apple 的 SimpleURLConnections 示例中的 generateBoundaryString 方法：

   - (NSString *)generateBoundaryString
   {
       // generate boundary string
       //
       // adapted from http://developer.apple.com/library/ios/#samplecode/SimpleURLConnections
       //
       // Note in iOS 6 and later, you can just:
       //
       //    return [NSString stringWithFormat:@"Boundary-%@", [[NSUUID UUID] UUIDString]];
       CFUUIDRef  uuid;
       NSString  *uuidStr;
       uuid = CFUUIDCreate(NULL);
       assert(uuid != NULL);
       uuidStr = CFBridgingRelease(CFUUIDCreateString(NULL, uuid));
       assert(uuidStr != NULL);
       CFRelease(uuid);
       return [NSString stringWithFormat:@"Boundary-%@", uuidStr];
   }
   

5. 如果您愿意，我以上面的一些代码为模型改装了您的代码：

   NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url];
   [request setHTTPMethod:@"POST"];
   NSString *boundary = @"---------------------------14737809831466499882746641449";
   NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary];
   [request addValue:contentType forHTTPHeaderField: @"Content-Type"];
   NSMutableData *body = [NSMutableData data];
   [body appendData:[[NSString stringWithFormat:@"--%@'r'n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
   [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name='"%@'"; filename='"%@'"'r'n", fieldName, [imagePath lastPathComponent]] dataUsingEncoding:NSUTF8StringEncoding]];
   [body appendData:[[NSString stringWithFormat:@"Content-Type: %@'r'n'r'n", [self mimeTypeForPath:imagePath]] dataUsingEncoding:NSUTF8StringEncoding]];
   [body appendData:[NSData dataWithData:imageData]];
   [body appendData:[[NSString stringWithFormat:@"'r'n--%@--'r'n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
   [request setHTTPBody:body];
   NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
   NSString *returnString = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding];
   NSLog(@"%@",returnString);
   

6. 就个人而言，我建议更改PHP代码以生成JSON响应（因为这会使您的应用程序更容易使用）。

顺便说一下，我已经用我的PHP代码测试了上述内容。如果您仍然遇到问题，我建议您也与我们分享您的PHP代码，因为格式良好的请求的构造与PHP代码的要求密切相关。