login.需要登录的viewController

#pragma 微信登录
- (void)login {

    if ([WXApi isWXAppInstalled]) {
        SendAuthReq *req = [[SendAuthReq alloc] init];
        req.scope = @"snsapi_userinfo";
        req.state = @"123";
        AppDelegate *dele = appDele;
        dele.wxDelegate = self;
        [WXApi sendReq:req];
    } else {
        // 未安装 隐藏按钮
    }
}

#pragma mark - 微信登录回调
-(void)loginSuccessByCode:(NSString *)code{
    NSLog(@"code %@",code);
    __weak typeof(*&self) weakSelf = self;
    
    AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
    manager.requestSerializer = [AFJSONRequestSerializer serializer];//请求
    manager.responseSerializer = [AFHTTPResponseSerializer serializer];//响应
    manager.responseSerializer.acceptableContentTypes = [NSSet setWithObjects:@"text/html",@"application/json", @"text/json",@"text/plain", nil, nil];
    //通过 appid  secret 认证code . 来发送获取 access_token的请求
    [manager GET:[NSString stringWithFormat:@"https://api.weixin.qq.com/sns/oauth2/access_token?appid=%@&secret=%@&code=%@&grant_type=authorization_code",Wechat_AppID,Wechat_AppSecret,code] parameters:nil progress:nil success:^(NSURLSessionDataTask * _Nonnull task, id  _Nullable responseObject) {
        NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:responseObject options:NSJSONReadingMutableContainers error:nil];
        NSLog(@"dic %@",dic);
        
        /*
         access_token   接口调用凭证
         expires_in access_token接口调用凭证超时时间，单位（秒）
         refresh_token  用户刷新access_token
         openid 授权用户唯一标识
         scope  用户授权的作用域，使用逗号（,）分隔
         unionid     当且仅当该移动应用已获得该用户的userinfo授权时，才会出现该字段
         */
        NSString* accessToken=[dic valueForKey:@"access_token"];
        NSString* openID=[dic valueForKey:@"openid"];
        
        [weakSelf.pfWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:[NSString stringWithFormat:@"http://sjgtest.youthbiger.com//mobile/index.php?act=app_login&app=1&app_userid=%@", openID]]]];
        // http://192.168.168.250/sjg.test.com/wap/tmpl/member/login.html
        
        [weakSelf requestUserInfoByToken:accessToken andOpenid:openID];
    } failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
        NSLog(@"error %@",error.localizedFailureReason);
    }];
}

-(void)requestUserInfoByToken:(NSString *)token andOpenid:(NSString *)openID{
    
    AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
    manager.requestSerializer = [AFJSONRequestSerializer serializer];
    manager.responseSerializer = [AFHTTPResponseSerializer serializer];
    [manager GET:[NSString stringWithFormat:@"https://api.weixin.qq.com/sns/userinfo?access_token=%@&openid=%@",token,openID] parameters:nil progress:nil success:^(NSURLSessionDataTask * _Nonnull task, id  _Nullable responseObject) {
        NSDictionary *dic = (NSDictionary *)[NSJSONSerialization JSONObjectWithData:responseObject options:NSJSONReadingMutableContainers error:nil];
        NSLog(@"dic  ==== %@",dic);
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"个人信息" message:[NSString stringWithFormat:@"%@", dic] delegate:nil cancelButtonTitle:@"取消" otherButtonTitles:nil, nil];
//        [alert show];
    } failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
        NSLog(@"error %ld",(long)error.code);
    }];
}

pay.需要支付的viewController

#pragma 微信支付
-(void)pay {

    if ([WXApi isWXAppInstalled]) {
        //调起微信支付
        PayReq* req             = [[PayReq alloc] init];
        req.openID              = Wechat_AppID;
        req.partnerId           = partnerId;
        req.prepayId            = prepayId;
        req.nonceStr            = nonceStr;
        req.timeStamp           = [timeStamp intValue];
        req.package             = @"Sign=WXPay";
        req.sign                = sign;
        [WXApi sendReq:req];
    } else {
        // 未安装
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"未安装" message:nil delegate:nil cancelButtonTitle:@"取消" otherButtonTitles:nil, nil];
        [alert show];
    }
}
#endif

// 支付成功处理
- (void)wxPayResult:(NSNotification *)noti {
    
    if ([noti.object isEqualToString:@"success"]) {
        [_pfWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"支付成功回调地址"]]];
    }

}

APPDelegate.h文件 写一个微信登录的代理方法

@protocol WxDelegate <NSObject>

@required
- (void)loginSuccessByCode:(NSString *)code;

@end

@property (weak, nonatomic) id wxDelegate;

AppDelegate.m

#pragma mark - 微信回调
- (void)onResp:(BaseResp *)resp {
    
    NSLog(@"%d, %d, %@", resp.errCode, resp.type, resp.errStr);
    // 登录
    if ([resp isKindOfClass:[SendAuthResp class]]) {
        if (resp.errCode == 0) {// 成功
            if ([_wxDelegate respondsToSelector:@selector(loginSuccessByCode:)]) {
                SendAuthResp *resp2 = (SendAuthResp *)resp;
                [_wxDelegate loginSuccessByCode:resp2.code];
                UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"登录成功" message:resp2.code delegate:nil cancelButtonTitle:@"取消" otherButtonTitles:nil, nil];
                [alert show];
            }
        } else {
            // 失败
            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"登录失败" message:nil delegate:nil cancelButtonTitle:@"取消" otherButtonTitles:nil, nil];
            [alert show];
        }
    } else if ([resp isKindOfClass:[PayResp class]]) {
        // 支付
        if (resp.errCode == 0) {
            [[NSNotificationCenter defaultCenter] postNotificationName:WXPayResultKey object:@"success"];
            // 支付成功
            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"支付成功" message:nil delegate:nil cancelButtonTitle:@"取消" otherButtonTitles:nil, nil];
            [alert show];
        } else {
            // 支付失败
            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"支付失败" message:nil delegate:nil cancelButtonTitle:@"取消" otherButtonTitles:nil, nil];
            [alert show];
        }
    }
}

This's All.
注：需要的库自行下载(´･_･`)