微信发票开发

一、使用GET请求获取微信access_token

access_token是公众号的全局唯一接口调用凭据，公众号调用各接口时都需使用access_token。开发者需要进行妥善保存。access_token的存储至少要保留512个字符空间。access_token的有效期目前为2个小时，需定时刷新，重复获取将导致上次获取的access_token失效。建议公众号开发者使用中控服务器统一获取和刷新access_token，其他业务逻辑服务器所使用的access_token均来自于该中控服务器，不应该各自去刷新，否则容易造成冲突，导致access_token覆盖而影响业务。

NSDictionary *parm = @{
                       @"grant_type":@"client_credential",
                       @"appid":appid,
                       @"secret":secret,
                       };
NSString *url = @"https://api.weixin.qq.com/cgi-bin/token";

二、使用拿到的access_token通过GET请求拿到ticket

ticket用于加强安全性。ticket的有效期目前为2个小时，需定时刷新。建议公众号开发者使用中控服务器统一获取和刷新ticket

NSDictionary *parm = @{
                       @"type":@"wx_card",
                       @"access_token":token,
                       };
NSString *url = @"https://api.weixin.qq.com/cgi-bin/ticket/getticket";

三、对拿到的ticket等信息进行排序加密,生成cardSign

将 api_ticket、appid、location_id、timestamp、nonce_str、card_id、card_type的value值进行字符串的字典序排序

将所有参数字符串拼接成一个字符串进行sha1加密，得到cardSign

NSMutableDictionary *cardSignDic = [NSMutableDictionary dictionary];
[cardSignDic setObject:nonceStr forKey:@"nonceStr"];
[cardSignDic setObject:timeStr forKey:@"timestamp"];
[cardSignDic setObject:apiTicket forKey:@"api_ticket"];
[cardSignDic setObject:@"INVOICE" forKey:@"cardType"];
[cardSignDic setObject:appid forKey:@"appid"];
NSMutableString *contentString = [NSMutableString string];
NSArray *values = [cardSignDic allValues];
//按字母顺序排序
NSArray *sortedArray = [values sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
    return [obj1 compare:obj2 options:NSNumericSearch];
}];
//拼接字符串
for (NSString *value in sortedArray) {
    [contentString appendFormat:@"%@", value];
}
NSString *cardSign = [self sha1:contentString];

sha1加密

- (NSString *)sha1:(NSString *)input {
  NSData *data = [input dataUsingEncoding:NSUTF8StringEncoding];
  uint8_t digest[CC_SHA1_DIGEST_LENGTH];
  CC_SHA1(data.bytes, (unsigned int)data.length, digest);
  NSMutableString *output = [NSMutableString stringWithCapacity:CC_SHA1_DIGEST_LENGTH * 2];
  for(int i = 0; i < CC_SHA1_DIGEST_LENGTH; i++){
      [output appendFormat:@"%02x", digest[i]];
  }
  return output;
}

四、通过调用微信Api跳转微信(注：传入的时间戳要和之前进行sha1加密的时间戳相同)

WXChooseInvoiceReq *cardReq = [[WXChooseInvoiceReq alloc]init];
cardReq.appID = appid;
cardReq.timeStamp = timeStamp;
cardReq.nonceStr = @"sfim_invoice";
cardReq.cardSign = cardSign;
[WXApi sendReq:cardReq];

五、在AppDelegate转发回调

- (BOOL)application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation {
    if ([WXApi handleOpenURL:url delegate:[weChatManager shareInstance]]) {
        return YES;
    }
    if ([self application:application handleOpenURL:url]) {
        return YES;
    }
    return NO;
}

六、在onResp方法里拿到发票的id,再用POST请求 拿到发票详细的信息

 WXChooseInvoiceResp *chooseInvoiceResp = (WXChooseInvoiceResp *)resp;
 NSArray *itemArray = chooseInvoiceResp.cardAry;
 NSMutableArray *resultArray = [NSMutableArray arrayWithCapacity:itemArray.count];
 for (WXInvoiceItem *item in itemArray) {
        NSMutableDictionary *dicM = [NSMutableDictionary dictionary];
        [dicM setObject:item.cardId ? item.cardId : @"" forKey:@"card_id"];
        [dicM setObject:item.encryptCode ? item.encryptCode : @"" forKey:@"encrypt_code"];
        [resultArray addObject:dicM];
}
NSDictionary *listParm = @{
                           @"item_list":resultArray,
                           };
NSString *url = [NSString stringWithFormat:@"https://api.weixin.qq.com/card/invoice/reimburse/getinvoicebatch?access_token=%@",self.accessToken];