Visual Basic HTML Agility Pack 如何从表格单元格中获取图像

Question

希望有人能提供帮助，因为我花了很长时间试图弄清楚这一点。我正在使用敏捷包从表中提取数据并将其放入数据网格中（数据网格并不重要，我只是使用它来查看提取是否有效）。无论如何，在表格的第一列中包含缩略图。我可以使用下面的代码提取所有文本，但我不知道如何从第一列中提取图像...有人可以帮忙吗？

PS 我已将网页保存为 MHL 文件，因为无法直接从中提取任何数据 - 我相信这与网站安全/凭据有关。不知道我是否让自己的事情变得更容易或更难。

Private Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Button1.Click

    ' '' original cods ***************************************
    Dim Web As New HtmlAgilityPack.HtmlWeb
    Dim Doc As New HtmlAgilityPack.HtmlDocument
    Dim RowCount As Integer = 1



    '   Doc = Web.Load("https://firefly.cardinalnewman.ac.uk/home/my")

    Doc.Load("E:\table.mht")


    Dim tables As HtmlAgilityPack.HtmlNodeCollection = Doc.DocumentNode.SelectNodes("//table")
    Dim img As HtmlAgilityPack.HtmlNodeCollection = Doc.DocumentNode.SelectNodes("//table")
    Dim Links As HtmlAgilityPack.HtmlNodeCollection = Doc.DocumentNode.SelectNodes("//table")
    Dim rows As HtmlAgilityPack.HtmlNodeCollection = tables(0).SelectNodes("//*[@id=HomeMyStudents]")


    For Each table As HtmlAgilityPack.HtmlNode In Doc.DocumentNode.SelectNodes("//*[@id='HomeMyStudents']/tbody/tr['RowCount']/td[1]")
        RowCount = RowCount + 1

        DGV.Rows.Add(Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing)

    Next
    RowCount = 0
    For Each table As HtmlAgilityPack.HtmlNode In Doc.DocumentNode.SelectNodes("//*[@id='HomeMyStudents']/tbody/tr['RowCount']/td[2]")
        RowCount = RowCount + 1
        '     DGV.Rows(RowCount).Cells(1).Value = somehow insert image
        ' this is the section where I need to grab the image in each cell and either save or place in my datagrid


    Next
    RowCount = 0
    For Each table As HtmlAgilityPack.HtmlNode In Doc.DocumentNode.SelectNodes("//*[@id='HomeMyStudents']/tbody/tr['RowCount']/td[3]")
        RowCount = RowCount + 1
        DGV.Rows(RowCount).Cells(2).Value = table.InnerText
    Next
    RowCount = 0
    For Each table As HtmlAgilityPack.HtmlNode In Doc.DocumentNode.SelectNodes("//*[@id='HomeMyStudents']/tbody/tr['RowCount']/td[4]")
        RowCount = RowCount + 1
        DGV.Rows(RowCount).Cells(3).Value = table.InnerText
    Next
    RowCount = 0
    For Each table As HtmlAgilityPack.HtmlNode In Doc.DocumentNode.SelectNodes("//*[@id='HomeMyStudents']/tbody/tr['RowCount']/td[5]")
        RowCount = RowCount + 1
        DGV.Rows(RowCount).Cells(4).Value = table.InnerText
    Next
    RowCount = 0
    For Each table As HtmlAgilityPack.HtmlNode In Doc.DocumentNode.SelectNodes("//*[@id='HomeMyStudents']/tbody/tr['RowCount']/td[6]")
        RowCount = RowCount + 1
        DGV.Rows(RowCount).Cells(5).Value = table.InnerText
    Next
    RowCount = 0
    For Each table As HtmlAgilityPack.HtmlNode In Doc.DocumentNode.SelectNodes("//*[@id='HomeMyStudents']/tbody/tr['RowCount']/td[7]")
        RowCount = RowCount + 1
        DGV.Rows(RowCount).Cells(6).Value = table.InnerText
    Next
    RowCount = 0
    For Each table As HtmlAgilityPack.HtmlNode In Doc.DocumentNode.SelectNodes("//*[@id='HomeMyStudents']/tbody/tr['RowCount']/td[8]")
        RowCount = RowCount + 1
        DGV.Rows(RowCount).Cells(7).Value = table.InnerText
    Next
    RowCount = 0
    For Each table As HtmlAgilityPack.HtmlNode In Doc.DocumentNode.SelectNodes("//*[@id='HomeMyStudents']/tbody/tr['RowCount']/td[9]")
        RowCount = RowCount + 1
        DGV.Rows(RowCount).Cells(8).Value = table.InnerText
    Next
    RowCount = 0
    For Each table As HtmlAgilityPack.HtmlNode In Doc.DocumentNode.SelectNodes("//*[@id='HomeMyStudents']/tbody/tr['RowCount']/td[10]")
        RowCount = RowCount + 1
        DGV.Rows(RowCount).Cells(9).Value = table.InnerText
    Next
    RowCount = 0
    For Each table As HtmlAgilityPack.HtmlNode In Doc.DocumentNode.SelectNodes("//*[@id='HomeMyStudents']/tbody/tr['RowCount']/td[11]")
        RowCount = RowCount + 1
        DGV.Rows(RowCount).Cells(10).Value = table.InnerText
    Next




End Sub  

Answer 1

所以，大概图像看起来像：

<img src="whatever.jpg"/> 

在标记中，对吗？

HAP 将允许您使用类似

的方式抓取图像节点

... .SelectNodes("./img") 

对于路径：

... .Attributes("src").Value()

从那里开始，我不知道有任何特定的 HAP 功能可以让您实际执行任何这样的 HTTP 请求，因此您需要WebClient。

Dim wc as new WebClient 

wc.DownloadFile(StringContainingThatSrcValue, PathToSaveFileTo) 

HTH！