我已经连续两天在上传图片到服务器方面进行了工作，因为有很多关于通过AFNetworking和NSURLSession以及其他上传方法的问题，所以我想问的是，我没有找到一个单一的答案来解释整个概念以及底层发生了什么事情。我还在YouTube上搜索过，但所有的内容都是使用Swift语言的，而且没有任何解释。最后，我发现这个答案与我之前看到的某些东西非常相似。
//Init the NSURLSession with a configuration
NSURLSessionConfiguration *defaultConfigObject = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *defaultSession = [NSURLSession sessionWithConfiguration: defaultConfigObject delegate: nil delegateQueue: [NSOperationQueue mainQueue]];
//Create an URLRequest
NSURL *url = [NSURL URLWithString:@"yourURL"];
NSMutableURLRequest *urlRequest = [NSMutableURLRequest requestWithURL:url];
//Create POST Params and add it to HTTPBody
NSString *params = @"api_key=APIKEY&email=example@example.com&password=password";
[urlRequest setHTTPMethod:@"POST"];
[urlRequest setHTTPBody:[params dataUsingEncoding:NSUTF8StringEncoding]];
//Create task
NSURLSessionDataTask *dataTask = [defaultSession dataTaskWithRequest:urlRequest completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
//Handle your response here
}];
[dataTask resume];
关于这个话题，最受欢迎的回答是由用户XJones给出的：
Here's code from my app to post an image to our web server:
// Dictionary that holds post parameters. You can set your post parameters that your server accepts or programmed to accept.
NSMutableDictionary* _params = [[NSMutableDictionary alloc] init];
[_params setObject:[NSString stringWithString:@"1.0"] forKey:[NSString stringWithString:@"ver"]];
[_params setObject:[NSString stringWithString:@"en"] forKey:[NSString stringWithString:@"lan"]];
[_params setObject:[NSString stringWithFormat:@"%d", userId] forKey:[NSString stringWithString:@"userId"]];
[_params setObject:[NSString stringWithFormat:@"%@",title] forKey:[NSString stringWithString:@"title"]];
// the boundary string : a random string, that will not repeat in post data, to separate post data fields.
NSString *BoundaryConstant = [NSString stringWithString:@"----------V2ymHFg03ehbqgZCaKO6jy"];
// string constant for the post parameter 'file'. My server uses this name: `file`. Your's may differ
NSString* FileParamConstant = [NSString stringWithString:@"file"];
// the server url to which the image (or the media) is uploaded. Use your server url here
NSURL* requestURL = [NSURL URLWithString:@""];
// create request
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData];
[request setHTTPShouldHandleCookies:NO];
[request setTimeoutInterval:30];
[request setHTTPMethod:@"POST"];
// set Content-Type in HTTP header
NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", BoundaryConstant];
[request setValue:contentType forHTTPHeaderField: @"Content-Type"];
// post body
NSMutableData *body = [NSMutableData data];
// add params (all params are strings)
for (NSString *param in _params) {
[body appendData:[[NSString stringWithFormat:@"--%@\r\n", BoundaryConstant] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n\r\n", param] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:@"%@\r\n", [_params objectForKey:param]] dataUsingEncoding:NSUTF8StringEncoding]];
}
// add image data
NSData *imageData = UIImageJPEGRepresentation(imageToPost, 1.0);
if (imageData) {
[body appendData:[[NSString stringWithFormat:@"--%@\r\n", BoundaryConstant] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"; filename=\"image.jpg\"\r\n", FileParamConstant] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[[NSString stringWithString:@"Content-Type: image/jpeg\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:imageData];
[body appendData:[[NSString stringWithFormat:@"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
}
[body appendData:[[NSString stringWithFormat:@"--%@--\r\n", BoundaryConstant] dataUsingEncoding:NSUTF8StringEncoding]];
// setting the body of the post to the reqeust
[request setHTTPBody:body];
// set the content-length
NSString *postLength = [NSString stringWithFormat:@"%d", [body length]];
[request setValue:postLength forHTTPHeaderField:@"Content-Length"];
// set URL
[request setURL:requestURL];
我的意思是，我自学时很难理解，因为没有解释，所以我想要一份详细的解释。如果有人发现这个问题很难，那么请给出一个关于整个过程的详细解释。直到现在，我找不到有关整个过程的教程，也没有任何面向初学者的解释。如果有人现在可以讲解一下这个概念以及上传过程，并提供一些参考步骤，那么明天要学习的学生就会更容易理解了。因此，任何可以详细解释上传过程并提供一些参考步骤的人都将受到高度赞赏。
注意：假设我有一个API和一个键“image”。