1.新建一个single view工程，导入ASIHttpRequest库，导入MobileCoreServices、CFNetwork、SystemConfiguration和libz1.2.5.dylib四个系统库

2.随便导入一张图片，比如haoyou.png

3.ViewController.h

    #import <UIKit/UIKit.h>        #import "ASIHTTPRequest.h"        #import "ASIFormDataRequest.h"        @interface ViewController : UIViewController <ASIHTTPRequestDelegate>        @property (nonatomic, copy)NSString *m_auth;        @end  

4.ViewController.m 添加两个按钮

    - (void)viewDidLoad {            [super viewDidLoad];                        UIButton *loginBtn = [UIButton buttonWithType:UIButtonTypeRoundedRect];            loginBtn.frame = CGRectMake(100, 20, 120, 40);            [loginBtn setTitle:@"登录" forState:UIControlStateNormal];            [loginBtn addTarget:self action:@selector(login) forControlEvents:UIControlEventTouchUpInside];            [self.view addSubview:loginBtn];                        UIButton *uploadBtn = [UIButton buttonWithType:UIButtonTypeRoundedRect];            uploadBtn.frame = CGRectMake(100, 80, 120, 40);            [uploadBtn setTitle:@"上传" forState:UIControlStateNormal];            [uploadBtn   addTarget:self action:@selector(upload) forControlEvents:UIControlEventTouchUpInside];             [self.view addSubview:uploadBtn];        }  

5.实现login和upload两个方法

    - (void)login {            NSURL *url = [NSURL URLWithString:@"..."];//此处省略请求url            //请求            ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];            request.tag = 10;            request.delegate = self;            [request startAsynchronous];        }                - (void)upload {            NSURL* url = [NSURL URLWithString:@"..."];//此处省略请求url            UIImage* img = [UIImage imageNamed:@"haoyou.png"];            NSData* data = UIImagePNGRepresentation(img);            //ASIFormDataRequest请求是post请求，可以查看其源码            ASIFormDataRequest* request = [ASIFormDataRequest requestWithURL:url];            request.tag = 20;            request.delegate = self;            [request setPostValue:self.m_auth forKey:@"m_auth"];        //    [request setFile:@"tabbar.png" forKey:@"haoyou"];//如果有路径，上传文件            [request setData:data  withFileName:@"tmp.png" andContentType:@"image/png" forKey:@"headimage"];        //               数据                文件名,随便起                 文件类型            设置key，要和服务端保持一致            [request startAsynchronous];        }  

6.实现协议

    - (void)requestFailed:(ASIHTTPRequest *)request {            NSLog(@"请求失败");        }                - (void)requestFinished:(ASIHTTPRequest *)request {            if (request.tag == 10) {                NSDictionary * dic = [NSJSONSerialization JSONObjectWithData:request.responseData options:0 error:nil];                self.m_auth = [dic objectForKey:@"m_auth"];                NSLog(@"%@", self.m_auth);            }            if (request.tag == 20) {                NSLog(@"%@", request.responseString);            }        }