iOS开发微信支付的方法

#import "ViewController.h"
#import "WXApiObject.h"
#import "WXApi.h"

- (void)viewDidLoad {
    [super viewDidLoad];

    UIButton * btn = [UIButton buttonWithType:UIButtonTypeCustom];
    btn.frame =CGRectMake(100, 100, 100, 50);
    [btn setTitle:@"点击支付" forState:UIControlStateNormal];
    btn.backgroundColor = [UIColor magentaColor];
    [btn addTarget:self action:@selector(weixinPay) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:btn];

}
//在这里我们要判断用户是否安装微信,如果未安装是不能够支付,因为微信不支持网页支付,不像支付宝那样,如果用户未安装支付宝,它会自动跳转网页支付,如果安装,则会跳转到支付宝客户端进行支付;微信则不可以,所以要判断下;
- (void)weixinPay {
//判断用户是否安装微信
  if ([WXApi isWXAppInstalled]) {
         NSString *res = [self doClickZhiFu];
         if( ![@"" isEqual:res] ){
        UIAlertView *alter = [[UIAlertView alloc] initWithTitle:@"支付失败" message:res delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [alter show];
         }
      }else{
      //未安装微信给出提示信息
         MBProgressHUD * hud = [MBProgressHUD showHUDAddedTo:self.view animated:YES];
            hud.mode = MBProgressHUDModeText;
            hud.labelText = @"您未安装微信,请选择其他方式支付!";
            hud.labelFont = [UIFont systemFontOfSize:13];
            hud.removeFromSuperViewOnHide = YES;
            hud.color = [UIColor grayColor];
            hud.minSize = CGSizeMake(300, 100);
            [hud hide:YES afterDelay:2];

       }


}

- (NSString *)doClickZhiFu
{
    //============================================================
    // V3&V4支付流程实现
    // 注意:参数配置请查看服务器端Demo
    // 更新时间：2015年11月20日
    //============================================================
    //在那里使用的url是微信里面的,在实际开发中,换成我们自己的url即可,让后台返回的参数就按照微信里面的来,这样我们下边就不用改什么了,只换个url即可(需要跟后台商定,一般都是需要传参数的);
    NSString *urlString   = @"http://wxpay.weixin.qq.com/pub_v2/app/app_pay.php?plat=ios";
    //解析服务端返回json数据
    NSError *error;
    //加载一个NSURL对象
    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:urlString]];
    //将请求的url数据放到NSData对象中
    NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
    if ( response != nil) {
        NSMutableDictionary *dict = NULL;
        //IOS5自带解析类NSJSONSerialization从response中解析出数据放到字典中
        dict = [NSJSONSerialization JSONObjectWithData:response options:NSJSONReadingMutableLeaves error:&error];
        if(dict != nil){
            NSMutableString *retcode = [dict objectForKey:@"retcode"];
            if (retcode.intValue == 0){
                NSMutableString *stamp  = [dict objectForKey:@"timestamp"];

                //这里的数据就是从上面那个url请求之后获取到消息结构体里面的内容
                //调起微信支付
                PayReq* req             = [[PayReq alloc] init];
                req.partnerId           = [dict objectForKey:@"partnerid"];
                req.prepayId            = [dict objectForKey:@"prepayid"];
                req.nonceStr            = [dict objectForKey:@"noncestr"];
                req.timeStamp           = stamp.intValue;
                req.package             = [dict objectForKey:@"package"];
                req.sign                = [dict objectForKey:@"sign"];
                //最关键的就是这里发送请求到微信,
                [WXApi sendReq:req];
                //日志输出
                NSLog(@"appid=%@\npartid=%@\nprepayid=%@\nnoncestr=%@\ntimestamp=%ld\npackage=%@\nsign=%@",[dict objectForKey:@"appid"],req.partnerId,req.prepayId,req.nonceStr,(long)req.timeStamp,req.package,req.sign );
                return @"";
            }else{
                return [dict objectForKey:@"retmsg"];
            }
        }else{
            return @"服务器返回错误，未获取到json对象";
        }
    }else{
        return @"服务器返回错误";
    }


}

#import "AppDelegate.h"
#import "WXApi.h"
#import "WXApiManager.h"

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
    //向微信注册wxd930ea5d5a258f4f,在微信平台注册后获取的
    [WXApi registerApp:@"wxb4ba3c02aa476ea1" withDescription:@"demo 2.0"];

    return YES;
}
//微信支付回调的结果,在这里可以做你想要的操作
- (BOOL)application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation {
//写了一个单例来处理微信支付结果的回调,处理在WXApiManager文件中操作
    return [WXApi handleOpenURL:url delegate:[WXApiManager sharedManager]];
}

#pragma mark - WXApiDelegate
- (void)onResp:(BaseResp *)resp {
    if ([resp isKindOfClass:[SendMessageToWXResp class]]) {
        if (_delegate
            && [_delegate respondsToSelector:@selector(managerDidRecvMessageResponse:)]) {
            SendMessageToWXResp *messageResp = (SendMessageToWXResp *)resp;
            [_delegate managerDidRecvMessageResponse:messageResp];
        }
    } else if ([resp isKindOfClass:[SendAuthResp class]]) {
        if (_delegate
            && [_delegate respondsToSelector:@selector(managerDidRecvAuthResponse:)]) {
            SendAuthResp *authResp = (SendAuthResp *)resp;
            [_delegate managerDidRecvAuthResponse:authResp];
        }
    } else if ([resp isKindOfClass:[AddCardToWXCardPackageResp class]]) {
        if (_delegate
            && [_delegate respondsToSelector:@selector(managerDidRecvAddCardResponse:)]) {
            AddCardToWXCardPackageResp *addCardResp = (AddCardToWXCardPackageResp *)resp;
            [_delegate managerDidRecvAddCardResponse:addCardResp];
        }
    }else if([resp isKindOfClass:[PayResp class]]){
        //支付返回结果，实际支付结果需要去微信服务器端查询
        NSString *strMsg,*strTitle = [NSString stringWithFormat:@"支付结果"];

        switch (resp.errCode) {
            case WXSuccess:{
                strMsg = @"支付结果：成功！";
                break;
            }
            default:{
                strMsg = [NSString stringWithFormat:@"支付结果：失败！retcode = %d, retstr = %@", resp.errCode,resp.errStr];
                break;
            }
        }
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:strTitle message:strMsg delegate:self cancelButtonTitle:@"取消" otherButtonTitles:nil, nil];
        [alert show];
    }

}