网上找了很多代码实际运行时报各种错，这里总结一下调试过程中遇到的报错：
1、access_token无效：
错误代码：{"errcode":40001,"errmsg":"invalid credential, access_token is invalid or not latest rid: 62b51859-648c2b4c-7722f316"}
分析原因：GetAccessToken返回的是JSON串，需要使用JObject tt =(JObject)JsonConvert.DeserializeObject(token);转换一下。
2、传入参数无效或不是JSON格式
错误代码：{"errcode":40169,"errmsg":"invalid length for scene, or the data is not json string rid: 62b53000-09ef0c32-425ac4f4"}
或：{"errcode":40129,"errmsg":"invalid scene rid: 62b54a10-06d2490b-1b4e6fc3"}
分析原因：参数格式必须是id=xxx这样的格式，不能是空或都其它格式。
经实测可正常运行的DEMO代码如下：
/// <summary>
/// 获取TOKEN
/// </summary>
/// <param name="strAPPID"></param>
/// <param name="strSecret"></param>
/// <returns></returns>
public static string GetAccessToken(string strAPPID, string strSecret)
{
string str = "";
string url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=" + strAPPID + "&secret=" + strSecret + "";
System.Net.WebRequest wRequest = System.Net.WebRequest.Create(url);
wRequest.Method = "GET";
wRequest.ContentType = "text/html;charset=UTF-8";
System.Net.WebResponse wResponse = wRequest.GetResponse();
Stream stream = wResponse.GetResponseStream();
StreamReader reader = new StreamReader(stream, System.Text.Encoding.Default);
str = reader.ReadToEnd(); //url返回的值
return str;
}
/// <summary>
/// HTTP GET方式请求数据.
/// </summary>
/// <param name="url">URL.</param>
/// <returns></returns>
public static string HttpGet(string url)
{
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
request.Method = "GET";
//request.ContentType = "application/x-www-form-urlencoded";
request.Accept = "*/*";
request.Timeout = 15000;
request.AllowAutoRedirect = false;
WebResponse response = null;
string responseStr = null;
try
{
response = request.GetResponse();
if (response != null)
{
StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
responseStr = reader.ReadToEnd();
reader.Close();
}
}
catch (Exception)
{
throw;
}
finally
{
request = null;
response = null;
}
return responseStr;
}
/// <summary>
/// 生成小程序二维码
/// </summary>
/// <param name="path">生成的小程序二维码存放的路径</param>
/// <param name="scene">参数 最多32位</param>
/// <param name="page">小程序页面路径 必须是已经发布了的</param>
/// <param name="width">二维码大小</param>
/// <param name="appid">小程序appid</param>
/// <param name="secret">小程序密钥</param>
/// <returns></returns>
public static bool CreateXcxQrCode(string path,string scene,string page,string width,string appid,string secret)
{
try
{
string token = GetAccessToken(appid, secret);
JObject tt =(JObject)JsonConvert.DeserializeObject(token);
string _url = "https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token=" + tt["access_token"].ToString();
string strURL = _url;
System.Net.HttpWebRequest request;
request = (System.Net.HttpWebRequest)System.Net.WebRequest.Create(strURL);
request.Method = "POST";
request.ContentType = "application/json;charset=UTF-8";
string options = "{\"scene\":\"" + scene + "\",\"page\":\"" + page + "\",\"width\":\"" + width + "\"}";
byte[] payload;
payload = System.Text.Encoding.UTF8.GetBytes(options);
request.ContentLength = payload.Length;
System.IO.Stream writer = request.GetRequestStream();
writer.Write(payload, 0, payload.Length);
writer.Close();
System.Net.HttpWebResponse response;
response = (System.Net.HttpWebResponse)request.GetResponse();
System.IO.Stream s;
s = response.GetResponseStream();
byte[] val = StreamToBytes(s);
System.IO.File.WriteAllBytes(path, val);
s.Dispose();
writer.Dispose();
}
catch(Exception e)
{
//log4net.LogManager.GetLogger("生成小程序二维码异常").Info(e);
return false;
}
return true;
}
public static byte[] StreamToBytes(System.IO.Stream stream)
{
List<byte> bytes = new List<byte>();
int temp = stream.ReadByte();
while (temp != -1)
{
bytes.Add((byte)temp);
temp = stream.ReadByte();
}
return bytes.ToArray();
}
