参考代码
Dim ul As String = "https://qyapi.weixin.qq.com/cgi-bin/user/convert_to_openid?access_token={0}"
Dim hc As New HttpClient(CExp(ul,Functions.Execute("GetQYAccessToken")))
Dim jo As New JObject
jo("userid") = "zhaoliu"
hc.Content = Jo.ToString
jo = JObject.Parse(hc.GetData)
If jo("errcode") = "0" Then
MessageBox.Show("成功")
msgbox(jo("openid"))
Else
MessageBox.Show(jo.ToString)
End If