php - 使用 xcode 和 php 将图像上传到网络服务器

Question

我在获取一些已获得的代码时遇到了一些问题，我在 php/html 方面的经验充其量是“有限的”，所以我希望我问这个问题不会看起来像个菜鸟。

我遇到的问题是无法将小图像上传到网络服务器。在过去的 4 到 5 个小时里，我一直在研究以下内容，现在英国已将近凌晨 2 点，我取得的唯一进展是不断变化

[NSString stringWithFormat:@"multipart/form-data; boundary=%@",boundary];

到

[NSString stringWithFormat:@"enctype=\"multipart/form-data\"; boundary=%@",boundary];

这让我的服务器在每次发送内容时停止给出内部错误。

代码在下面，它在这个网站的许多页面上，我找不到原作者来表示信任。当我在接收 php 文件中有 print_r($_FILES); 时，我目前得到一个空数组。

任何帮助都将不胜感激，在此先感谢。

NSString *urlString = @"http://mysite/upload_image.php";

UIImage * img = [UIImage imageNamed:@"mypic.png"];
NSData *imageData = UIImageJPEGRepresentation(img, 90);

NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init] ;
[request setURL:[NSURL URLWithString:urlString]];
[request setHTTPMethod:@"POST"];

NSString *boundary = @"---------------------------14737809831466499882746641449";
NSString *contentType = [NSString stringWithFormat:@"enctype=\"multipart/form-data\"; boundary=%@",boundary];
[request addValue:contentType forHTTPHeaderField: @"Content-Type"];


NSMutableData *body = [NSMutableData data];
[body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[@"Content-Disposition: attachment; name=\"image\"; filename=\"davesfile.jpg\"\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[@"Content-Type: application/octet-stream\r\n\r\n" 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);

Answer 1

几个 react :

1. 如果您使用 AFNetworking ，创建这类请求的过程更简单，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 来根据扩展名获取 mime 类型，而不是对其进行硬编码:

   - (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 获取 NSData。如果你想或必须这样做，但我通常更喜欢发送原始数据，直接通过 UIImage 绕过往返，这会导致图像质量下降和元数据丢失。相反，您可能想直接获取 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];
   

   如果您真的必须通过 UIImage 进行往返，那么您可能希望使用 imageWithContentsOfFile 而不是 imageNamed，因为后者会缓存不必要的图像。

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参数(您似乎没有这样做)，您可以只为该参数传递nil。但关键是它支持额外的参数，如果你需要的话。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。

   这使用了 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，我仿照上面的一些代码改进了您的代码:

   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. 就我个人而言，我建议更改您的 PHP 代码以生成 JSON 响应(因为这将更容易让您的应用使用)。

顺便说一下，我已经用我的 PHP 代码测试了上面的内容。如果您仍有问题，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。