主题：发送图片问题

Dim jo As New JObject
Dim ja As New JArray
jo("touser") = "ofjtFwBSZ5cNqTKLSKx2TNEAxfBI"
jo("msgtype") = "news"
For i As Integer = 1 To 1 '可以一次发送最多8个图文消息,这里只发送了1个
    Dim ao As New JObject()
    ao("title") = "特朗普提名保守派大法官" '标题
    ao("description") = "特朗普在白宫提名尼尔·戈萨奇为美国最高法院大法官" '描述
    ao("url") = "http://news.ifeng.com/a/20170201/50640529_0.shtml" '连接
    ao("picurl") = "https://ss1.baidu.com/6ONXsjip0QIZ8tyhnq/it/u=1632653074,1222564348&fm=80&w=179&h=119&img.JPEG" '图片
    ja.Add(ao)

那我现在想用本地图片，有没有什么办法

上传图片素材

上传图片素材的代码，可以在命令窗口测试：

Dim url As String = "https://api.weixin.qq.com/cgi-bin/material/add_material?access_token={0}&type=image"
Dim hc As new HttpClient(CExp(url, Functions.Execute("GetAccessToken")))
hc.Files.Add("media","c:\data\sample.jpg") '指定要上传的图片文件
Dim jo As JObject = JObject.Parse( hc.getdata)
If jo("errcode") Is Nothing Then
    Dim dr As DataRow = DataTables("Materials").AddNew()
    dr("Type") = "image"
    dr("mediaID") = jo("media_id")
    dr("URL") = jo("url")
    dr("UpdateTime") = Date.Now
    dr("FileName") = "sample.jpg"
    dr.Save()
Else
    MessageBox.Show(jo.ToString)
End If