网站搜索框使用微信扫码功能

<script src="http://res.wx.qq.com/open/js/jweixin-1.1.0.js"></script>

$(function () {
  /**
   * 判断是否微信内部打开页面
   * */
  function isWeiXin() {
    var ua = window.navigator.userAgent.toLowerCase();
    console.log(ua);//mozilla/5.0 (iphone; cpu iphone os 9_1 like mac os x) applewebkit/601.1.46 (khtml, like gecko)version/9.0 mobile/13b143 safari/601.1
    if (ua.match(/MicroMessenger/i) == 'micromessenger') {
      return true;
    }
    else {
      return false;
    }
  }
  /**
   * 只有微信内部页面打开才能用
   * */
  if (isWeiXin()) {
    $.ajax({
      type: "post",
      url: "/Home/GetSingDataAsync",
      data: {
        "url": location.href.split('#')[0]
      },
      dataType: "json",
      success: function (data) {
        alert(JSON.stringify(data));
        wx.config({
          debug: true, // 开启调试模式,调用的所有api的返回值会在客户端alert出来，若要查看传入的参数，可以在pc端打开，参数信息会通过log打出，仅在pc端时才会打印。
          appId: data.appId, // 必填，公众号的唯一标识
          timestamp: data.timestamp, // 必填，生成签名的时间戳
          nonceStr: data.nonceStr, // 必填，生成签名的随机串
          signature: data.signature,// 必填，签名，见附录1
          jsApiList: [
            'checkJsApi',
            'startRecord',
            'stopRecord',
            'translateVoice',
            'scanQRCode',// 微信扫一扫接口
            'openCard'
          ] // 必填，需要使用的JS接口列表，所有JS接口列表见附录2
        });
        wx.error(function (res) {
          alert("出错了：" + res.errMsg);//这个地方的好处就是wx.config配置错误，会弹出窗口哪里错误，然后根据微信文档查询即可。
        });
        wx.ready(function () {
          wx.checkJsApi({
            jsApiList: ['scanQRCode'],
            success: function (res) {
              //扫描二维码
              wx.scanQRCode({
                needResult: 1, // 默认为0，扫描结果由微信处理，1则直接返回扫描结果，
                scanType: ["qrCode"], // 可以指定扫二维码还是一维码，默认二者都有
                success: function (res) {
                  var result = res.resultStr; // 当needResult 为 1 时，扫码返回的结果
                  alert(result);//因为我这边是扫描后有个链接，然后跳转到该页面
                },
                error: function () {
                  console.log('123');
                }
              });
            }
          });
        });
      },
      error: function (url) {
        alert("An error occurred!");
      }
    });
  } else {
    alert("请使用微信打开");
  }
}) 

public class HomeController : Controller
{
  //把APPID和APP_SECRET换成你自己的
  private const string APPID = "******";
  private const string APP_SECRET = "******";
  //为了调试方便我这里第一次把Token和Ticket获取到之后就写死了，应该写入缓存（7200s过期）
  private static string Token = "24_cQsz9scwyXLnPaAes5JlfHTfuQ2e3Iw5L8JyWfUpQiMnTk4IToOTZ7dP0Fv190ZHTy5ST--jeuDzYwoUj_hvhSHDX288YYLYVcrmvMzRPwld8ccTTzWGNTKZz53jYKDy5f8U1E886msDPsrwORGbAJABET";
  private static string Ticket = "HoagFKDcsGMVCIY2vOjf9qZA_fkPP3enjnT58qu16hzZN-3kwAP0NK6jgQM0jyAc0sK8cxaGkT9_DSgp6cHCpw";
  public ActionResult Index()
  {

    return View();
  }

  public ActionResult About()
  {
    ViewBag.Message = "Your application description page.";

    return View();
  }

  public ActionResult Contact()
  {
    ViewBag.Message = "Your contact page.";

    return View();
  }


  public async Task GetToken()
  {
    await GetTicketAsync();
  }
  //获取token和ticket
  private async Task<string> GetTicketAsync()
  {

    var tokenUrl = $"https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid={APPID}&secret={APP_SECRET}";

    var client = new System.Net.WebClient();
    client.Encoding = Encoding.UTF8;
    client.Headers.Add("Content-Type", "Application/x-www-form-urlencoded");
    var responseData = client.UploadData(tokenUrl, "POST", new byte[0]);
    var responseText = Encoding.UTF8.GetString(responseData);
    var token = JsonConvert.DeserializeAnonymousType(responseText, new { access_token = "", expires_in = "" });


    Token = token.access_token;
    var ticketUrl = $"https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token={Token}&type=jsapi";
    var ticResponseData = client.UploadData(ticketUrl, "POST", new byte[0]);
    var ticResponseText = Encoding.UTF8.GetString(ticResponseData);
    var ticket = JsonConvert.DeserializeAnonymousType(ticResponseText, new { errcode = "", errmsg = "", ticket = "", expires_in = "" });
    Ticket = ticket.ticket;
    return "";
  }
  //获取签名字符串
  public async Task<string> GetSingDataAsync(string url)
  {

    var sign = new SignData();
    sign.appId = APPID;
    sign.nonceStr = Create_nonce_str();
    sign.timestamp = Create_timestamp();
    //var url = Request.Url.AbsoluteUri;
    if (url.IndexOf('#') > 0)
    {
      url = url.Substring(0, url.IndexOf('#'));
    }
    sign.url = url;
    var string1 = "jsapi_ticket=" + Ticket +
        "&noncestr=" + sign.nonceStr +
        "&timestamp=" + sign.timestamp +
        "&url=" + sign.url;

    //var string1 = GetTestSign();

    var sha1 = SHA1.Create();
    sign.signature = ByteToHex(sha1.ComputeHash(Encoding.UTF8.GetBytes(string1)));
    return JsonConvert.SerializeObject(sign);
  }
  //测试签名字符串，和微信官方提供的一样，用来测试签名方法是否正确
  private string GetTestSign()
  {
    var nonceStr = "Wm3WZYTPz0wzccnW";
    var ticket = "sM4AOVdWfPE4DxkXGEs8VMCPGGVi4C3VM0P37wVUCFvkVAy_90u5h9nbSlYy3-Sl-HhTdfl2fzFy1AOcHKP7qg";
    var timestamp = "1414587457";
    var url = "http://mp.weixin.qq.com?params=value";
    var string1 = "jsapi_ticket=" + ticket +
        "&noncestr=" + nonceStr +
        "&timestamp=" + timestamp +
        "&url=" + url;
    return string1;
  }

  /// <summary>
  /// 随机字符串
  /// </summary>
  /// <returns></returns>
  private string Create_nonce_str()
  {
    return Guid.NewGuid().ToString().Substring(0, 8);
  }
  /// <summary>
  /// 时间戳
  /// </summary>
  /// <returns></returns>
  private string Create_timestamp()
  {
    return (DateTime.Now.Ticks / 100000000).ToString();
  }
  private string ByteToHex(byte[] hash)
  {
    var sb = new StringBuilder();
    foreach (var b in hash)
    {
      sb.Append(b.ToString("x2"));
    }
    return sb.ToString();
  }
}