隨手寫了個京東發票助手

因爲需要批量下載京東的電子發票，隨手用VB .NET寫了個WinForm小工具，爲了圖省事通過 WebBrowser 結合 WebClient 實現了“半自動”的下載，一次要下載很多發票時能省不少力氣。

比較值得記下來的幾個賣點：

1.共享Cookie，實現 WebClient 下載 WebBrowser 中選定的鏈接

    ''' <summary>
    ''' 下載保存文件
    ''' </summary>
    ''' <param name="url"></param>
    Private Shared Sub saveFile(ByVal url As String, doc As HtmlDocument)
        Dim strCookies As String = doc.Cookie
        'If String.IsNullOrEmpty(strCookies) Then
        '    strCookies = CookieHelper.GetCookieString(url)
        'End If
        Try
            Using wc As New Net.WebClient
                wc.Headers.Add("Cookie", strCookies) '共享 WebBrowser.Cookie
                wc.DownloadFile(url, getFilename(url))
            End Using
        Catch ex As Exception
            Stop
        End Try
    End Sub

2.查找頁面元素，實現自動點擊

    Private Shared Function findElement(ByVal doc As HtmlDocument, ByVal elementId As String) As HtmlElement
        Dim ret As HtmlElement = Nothing
        Try
            ret = doc.GetElementById(elementId)
        Catch ex As Exception
            Debug.Print("findElement err:{0}", ex.Message)
        End Try

        Return ret
    End Function

    Private Shared Function findElement(doc As HtmlDocument, ByVal href As String, ByVal innerText As String) As HtmlElement
        Dim ret As HtmlElement = Nothing
        For Each element As HtmlElement In doc.Links
            If element.InnerText = innerText AndAlso element.GetAttribute("href") = href Then
                ret = element
                Exit For
            End If
        Next
        Return ret
    End Function

    '通過 InvokeMember 觸發點擊動作
    _currElemet = findElement(wb.Document, url, "發票詳情")
    If _currElemet IsNot Nothing Then
        _currElemet.InvokeMember("click")
    Else
        Debug.Print("findElement NOT FOUND " & url)
    End If

 

源代碼發佈在：https://github.com/towerbit/JDReceipt