AFN 的表单请求 （iOS）

今天遇到一个问题，图灵机器人平台的接口使用的是表单请求的方式，由于项目一开始是使用的iOS原生的NSURLSession，公司的项目一直都是使用的application/json的请求方式，一时之间很尴尬，因为很少使用multipart/form-data 表单方式请求;
接着用Postman 工具测了一下，请求是没有问题的，但是尝试把Postman提供的Objectve-C代码拷贝到iOS Demo上运行，但是并行不通，代码如下：

#import <Foundation/Foundation.h>

NSDictionary *headers = @{ @"content-type": @"multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW",
                           @"Content-Type": @"application/x-www-form-urlencoded",
                           @"cache-control": @"no-cache",
                           @"Postman-Token": @"e714247c-6bba-4e6a-9732-36a3672bcbba" };
NSArray *parameters = @[ @{ @"name": @"apiKey", @"value": @"1" },
                         @{ @"name": @"deviceId", @"value": @"123456789" },
                         @{ @"name": @"uid", @"value": @"10000" } ];
NSString *boundary = @"----WebKitFormBoundary7MA4YWxkTrZu0gW";

NSError *error;
NSMutableString *body = [NSMutableString string];
for (NSDictionary *param in parameters) {
    [body appendFormat:@"--%@\r\n", boundary];
    if (param[@"fileName"]) {
        [body appendFormat:@"Content-Disposition:form-data; name=\"%@\"; filename=\"%@\"\r\n", param[@"name"], param[@"fileName"]];
        [body appendFormat:@"Content-Type: %@\r\n\r\n", param[@"contentType"]];
        [body appendFormat:@"%@", [NSString stringWithContentsOfFile:param[@"fileName"] encoding:NSUTF8StringEncoding error:&error]];
        if (error) {
            NSLog(@"%@", error);
        }
    } else {
        [body appendFormat:@"Content-Disposition:form-data; name=\"%@\"\r\n\r\n", param[@"name"]];
        [body appendFormat:@"%@", param[@"value"]];
    }
}
[body appendFormat:@"\r\n--%@--\r\n", boundary];
NSData *postData = [body dataUsingEncoding:NSUTF8StringEncoding];

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://iot-ai.tuling123.com/app-author/unbind"]
                                                       cachePolicy:NSURLRequestUseProtocolCachePolicy
                                                   timeoutInterval:10.0];
[request setHTTPMethod:@"POST"];
[request setAllHTTPHeaderFields:headers];
[request setHTTPBody:postData];

NSURLSession *session = [NSURLSession sharedSession];
NSURLSessionDataTask *dataTask = [session dataTaskWithRequest:request
                                            completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
                                                if (error) {
                                                    NSLog(@"%@", error);
                                                } else {
                                                    NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *) response;
                                                    NSLog(@"%@", httpResponse);
                                                }
                                            }];
[dataTask resume];

在网上找了各种文章，结果都没有给整通，后来看到有的博客介绍了AFN上面对表单请求的支持，然后尝试了一下，先把代码贴出来，记录一下：

NSMutableURLRequest *request = [[AFHTTPRequestSerializer serializer] multipartFormRequestWithMethod:@"POST" URLString:URLString parameters:nil constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
        
        NSArray *keys = [parameters allKeys];
        for (id key in keys) { //拼接表单数据
            [formData appendPartWithFormData:[parameters[key] dataUsingEncoding:NSUTF8StringEncoding] name:key];
        }
        
    } error:nil];
    
    
    AFURLSessionManager *manager = [[AFURLSessionManager alloc] initWithSessionConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]];
    
    NSURLSessionUploadTask *uploadTask;
    uploadTask = [manager uploadTaskWithStreamedRequest:request progress:nil completionHandler:^(NSURLResponse * _Nonnull response, id  _Nullable responseObject, NSError * _Nullable error) {
        if (error) {
            NSLog(@"Error: %@", error);
            if (failure) {
                failure(error);
            }
        } else {
            NSLog(@"%@", responseObject);
            if (success) {
                success(responseObject);
            }
        }
    }];
    
    [uploadTask resume];