iOS–表单formdata上传文件

背景：使用multipart/form-data格式提交图片或者文件到服务器。

方法：使用http请求POST方式，然后在请求头里设置Content-Type为multipart/from-data指定请求的格式。

参数格式：

普通参数： --boundry\r\n Content-Disposition: form-data; name=\"%@\"\r\n            \r\n value \r\n 文件参数： --boundry\r\n Content-Disposition:form-data; name=\"%@\"; filename=\"%@\"\r\nContent-Type: %@\r\n          \r\n data \r\n 参数结尾： --boundry--\r\n

例子：

服务器要求传参：{”upload”: imgdata, “uid”: uid}

#pragma mark ------ 上传头像 POST /file/uploadHead - (void)uploadHeadImage:(UIImage *)image usrId:(NSString *)usrId onSuccess:(void (^)(NSDictionary *dict))onSuccess onFailure:(void(^)(NSError *error))onFailure { //BaseWebAddr：服务器地址 NSString *urlStr = [BaseWebAddr stringByAppendingString:@"file/uploadHead"]; NSURL *url = [NSURL URLWithString:urlStr]; //在此声明一个字符串常量,代替下面的 BOUNDARY 字符串 // NSString * const POST_BOUNDS = @"----iOSKitFormBoundarycIO0B6mmsXU6koBg"; NSData *imageData; NSString *imageFormat; if (UIImagePNGRepresentation(image) != nil) { imageFormat = @"Content-Type: image/png \r\n"; imageData = UIImagePNGRepresentation(image); }else{ imageFormat = @"Content-Type: image/jpeg \r\n"; imageData = UIImageJPEGRepresentation(image, 1.0); } NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url]; request.HTTPMethod = @"POST"; //设置请求实体 NSMutableData *body = [NSMutableData data]; ///文件参数 [body appendData:[self getDataWithString:@"--BOUNDARY\r\n" ]]; NSString *disposition = [NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"; filename=\"%@.jpg\"\r\n",@"upload",usrId]; [body appendData:[self getDataWithString:disposition ]]; [body appendData:[self getDataWithString:imageFormat]]; [body appendData:[self getDataWithString:@"\r\n"]]; [body appendData:imageData]; [body appendData:[self getDataWithString:@"\r\n"]]; //普通参数 [body appendData:[self getDataWithString:@"--BOUNDARY\r\n" ]]; //上传参数需要key NSString *dispositions = [NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n",@"uid"]; [body appendData:[self getDataWithString:dispositions ]]; [body appendData:[self getDataWithString:@"\r\n"]]; [body appendData:[self getDataWithString:usrId]]; [body appendData:[self getDataWithString:@"\r\n"]]; //参数结束 [body appendData:[self getDataWithString:@"--BOUNDARY--\r\n"]]; request.HTTPBody = body; //设置请求体长度 NSInteger length = [body length]; [request setValue:[NSString stringWithFormat:@"%ld",length] forHTTPHeaderField:@"Content-Length"]; //设置 POST请求文件上传 [request setValue:@"multipart/form-data; boundary=BOUNDARY" forHTTPHeaderField:@"Content-Type"]; NSURLSessionDataTask *dataTask = [self.session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) { NSJSONSerialization *object = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil]; NSDictionary *dict = (NSDictionary *)object; NSLog(@"=====%@",[dict objectForKey:@"success"]); }]; //开始任务 [dataTask resume]; } -(NSData *)getDataWithString:(NSString *)string{ NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding]; return data; }