上传永久素材

关于上传永久素材的接口说明，请参考：
https://developers.weixin.qq.com/doc/offiaccount/Asset_Management/Adding_Permanent_Assets.html

首先新建一个表，表名为Materials，用于储存永久素材信息，表结构如下：

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

上传缩略图素材

上传缩略图素材的代码完全相同，只需将type参数改为thumb即可：

Dim url As String = "https://api.weixin.qq.com/cgi-bin/material/add_material?access_token={0}&type=thumb"
Dim hc As new HttpClient(CExp(url, Functions.Execute("GetAccessToken")))
hc.Files.Add("media","c:\data\006s.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") = "thumb"
    dr("mediaID") = jo("media_id")
    dr("URL") = jo("url")
    dr("UpdateTime") = Date.Now
    dr("FileName") = "006s.jpg"
    dr.Save()
Else
    MessageBox.Show(jo.ToString)
End If

上传语音素材

上传语音素材的代码也基本相同，只需将type参数改为voice，另语音素材上传成功后不会返回URL：

Dim url As String = "https://api.weixin.qq.com/cgi-bin/material/add_material?access_token={0}&type=voice"
Dim hc As new HttpClient(CExp(url, Functions.Execute("GetAccessToken")))
hc.Files.Add("media","c:\data\sample.mp3") '指定要上传的语音文件
Dim jo As JObject = JObject.Parse( hc.getdata)
If jo("errcode") Is Nothing Then
    Dim dr As DataRow = DataTables("Materials").AddNew()
    dr("Type") = "voice"
    dr("mediaID") = jo("media_id")
    dr("UpdateTime") = Date.Now
    dr("FileName") = "sample.mp3"
    dr.Save()
Else
    MessageBox.Show(jo.ToString)
End If

上传视频素材

根据接口说明，上传视频素材有点特殊，需要同时提交一个JSON格式的视频素材说明，代码可以参考：

Dim url As String = "https://api.weixin.qq.com/cgi-bin/material/add_material?access_token={0}&type=video"
Dim hc As New HttpClient(CExp(url, Functions.Execute("GetAccessToken")))
hc.Files.Add("media","c:\data\samlpe.mp4") '指定要上传的视频文件
Dim jo As New JObject
jo("title") = "视频标题"
jo("introduction") = "视频简介"
hc.FormData.Add("description", jo.ToString)
jo = JObject.Parse(hc.getdata)
If jo("errcode") Is Nothing Then
    Dim dr As DataRow = DataTables("Materials").AddNew()
    dr("Type") = "video"
    dr("mediaID") = jo("media_id")
    dr("UpdateTime") = Date.Now
    dr("FileName") = "sample.mp4"
    dr.Save()
Else
    MessageBox.Show(jo.ToString)
End If

上传图文素材

上传永久图文素材的代码参考：

Dim ar As New JArray
For i As Integer = 1 To 1 '可以有多段图文
    Dim ao As New JObject
    ao("title") = "标题"
    ao("thumb_media_id") = "eHDdfBQmRtOJ-PtkD6WENiWR_BUO5GO3cWv7uZAGbIk" '缩略图ID
    ao("author") = "作者"
    ao("digest") = "图文消息摘要"
    ao("show_cover_pic") = "1" '显示封面
    ao("content") = "图文消息内容,可以包括HTML标签"
    ao("content_source_url") = "http://www.foxtable.com" '点击"阅读原文"后的URL
    ao("need_open_comment") = 1 '是否打开评论，0不打开，1打开
    ao("only_fans_can_comment") = 1 '是否粉丝才可评论，0所有人可评论，1粉丝才可评论
    ar.add(ao)
Next
Dim jo As New JObject
jo("articles") = ar
Dim url As String = "https://api.weixin.qq.com/cgi-bin/material/add_news?access_token={0}"
Dim hc As new HttpClient(CExp(url, Functions.Execute("GetAccessToken")))
hc.Content = jo.ToString()
jo = JObject.Parse(hc.GetData)
If jo("errcode") Is Nothing Then
    Dim dr As DataRow = DataTables("Materials").AddNew()
    dr("Type") = "news"
    dr("mediaID") = jo("media_id")
    dr("UpdateTime") = Date.Now
    dr("Content") = ar.ToString
    dr.Save()
Else
    MessageBox.Show(jo.ToString)
End If