iOS 微信支付总结

#pragma mark   ==============微信支付==============

- (void) wechatPay:(NSDictionary *)dic{//目前只需要prepay_id
    NSLog(@"开始微信支付");

    //首先判断是否安装wechat
    
    if([WXApi isWXAppInstalled]){
        
        //生成订单
            
        NSLog(@"l-----:%@ ",dic);
    
        NSString *prePayid = dic[@"prepay_id"];
        
//        //获取到prepayid后进行第二次签名
        
        NSString    *package, *time_stamp, *nonce_str;
        //设置支付参数
        time_t now;
        time(&now);
        time_stamp  = [NSString stringWithFormat:@"%ld", now];
        nonce_str    = [WXUtil md5:time_stamp];
        //重新按提交格式组包，微信客户端暂只支持package=Sign=WXPay格式，须考虑升级后支持携带package具体参数的情况
        //package       = [NSString stringWithFormat:@"Sign=%@",package];
        package         = @"Sign=WXPay";
        //第二次签名参数列表
        NSMutableDictionary *signParams = [NSMutableDictionary dictionary];
        [signParams setObject: APPP_ID        forKey:@"appid"];
        [signParams setObject: nonce_str    forKey:@"noncestr"];
        [signParams setObject: package      forKey:@"package"];
        [signParams setObject: MCH_ID        forKey:@"partnerid"];
        [signParams setObject: time_stamp   forKey:@"timestamp"];
        [signParams setObject: prePayid     forKey:@"prepayid"];
        //[signParams setObject: @"MD5"       forKey:@"signType"];
        //生成签名
        NSString *sign  = [self createMd5Sign:signParams];//获取微信预付款id
        if ( prePayid != nil && sign != nil) {//调起微信支付
            PayReq* req             = [[PayReq alloc] init];
            req.openID              = APPP_ID;//
            req.partnerId           = MCH_ID;//商户号
            req.prepayId            = prePayid;//预付订单号，后台返回的
            req.nonceStr            = nonce_str;//随机串            req.timeStamp           = time_stamp.intValue;//时间戳            req.package             = @"Sign=WXPay";//此地方一定要写成这种格式，后台生成预付订单时也是如此，不要写成prepay_id = @"wx...."
            req.sign                = sign;            BOOL sendRes = [WXApi sendReq:req];
            if (sendRes) {
                NSLog(@"唤起成功");
            }else {
                NSLog(@"唤起失败");
                
            }
            //日志输出
            DLog(@"appid=%@\npartid=%@\nprepayid=%@\nnoncestr=%@\ntimestamp=%ld\npackage=%@\nsign=%@",req.openID,req.partnerId,req.prepayId,req.nonceStr,(long)req.timeStamp,req.package,req.sign );
        }else{
            DLog(@"预付订单生成失败");
            [XWPrompt showPromptMessage:@"订单失败"];
        }
        
    }else{
        
        [SMAlertView showAlertWithTitle:@"您还没有安装微信" message:@"是否安装？" cancelTitle:@"否" cancelTitleColor:colorForDeepGrayNormal otherTitle:@"是" otherTitleColor:colorForNavBgColor completion:^(BOOL cancelled) {
            
            if (!cancelled) {
                
                DLog(@"%d",cancelled);
                
                [[ UIApplication sharedApplication] openURL:[NSURL URLWithString:[WXApi getWXAppInstallUrl]]];
                
            }
        }];
        
    }
}

//创建package签名
-(NSString*) createMd5Sign:(NSMutableDictionary*)dict
{
    NSMutableString *contentString  =[NSMutableString string];
    NSArray *keys = [dict allKeys];
    //按字母顺序排序
    NSArray *sortedArray = [keys sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
        return [obj1 compare:obj2 options:NSNumericSearch];
    }];
    //拼接字符串
    for (NSString *categoryId in sortedArray) {
        if (   ![[dict objectForKey:categoryId] isEqualToString:@""]
            && ![categoryId isEqualToString:@"sign"]
            && ![categoryId isEqualToString:@"key"]
            )
        {
            [contentString appendFormat:@"%@=%@&", categoryId, [dict objectForKey:categoryId]];
        }
        
    }
    //添加key字段
    [contentString appendFormat:@"key=%@", PARTNER_ID];
    //得到MD5 sign签名
    NSString *md5Sign =[WXUtil md5:contentString];
    
    return md5Sign;
}