使用xcode和php将图像上传到网络服务器

时间：2013-11-17 01:45:54

标签： php objective-c image webserver

我在获取一些我已经获得的代码时遇到了一些麻烦，我对php / html的体验充其量只是“有限”，所以我希望通过询问这一点，我看起来不像太多的菜鸟。

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4-5个小时里，我已经玩过以下几个小时，在英国已经快到凌晨2点，我所取得的唯一进步一直在变化

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

到

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

这使我的服务器每次发送内容时都会停止发出内部错误。

代码如下，它位于本网站的多个页面上，我找不到原作者给予的信任。当我在接收php文件中有print_r($_FILES);时，我正在获取一个空数组。

提前感谢任何帮助，非常感谢。

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);

1 个答案:

答案 0 :(得分：7)

一些反应：

  1. 如果您使用AFNetworking，创建这些请求的过程会更简单，让您自己摆脱构建请求的杂草：

    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. 顺便说一句，我通常使用MobileCoreServices.framework来获取基于扩展名的mime类型，而不是硬编码：

    - (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片检索到UIImage，然后使用UIImageJPEGRepresentation获取NSData。如果您愿意或必须这样做，但我通常更喜欢发送原始数据，直接绕过UIImage的往返，这会导致图像质量下降和元数据丢失。相反，您可能想直接抓取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。

    < / LI>

  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还支持其他参数。我还使用异步网络请求，因为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，我会根据以上代码模拟您的代码：

    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，我建议您更改PHP代码以生成JSON响应（因为这会让您的应用更容易使用）。

    7. 顺便说一下，我用我的PHP代码测试了上面的内容。如果您仍然遇到问题，我建议您与我们共享您的PHP代码，因为构造格式良好的请求与PHP代码所需的内容密切相关。

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