Question

我有一个程序（目前是winform），可以加载网站，截取屏幕截图并转换为位图，然后保存。我遇到的问题是，它无法将数据加载到网站中。为什么我认为这样做，它可以快速截取屏幕截图并且没有时间完全加载。

实施例：在“统计”下，应该有一堆似乎尚未加载的信息。

我尝试在一些地方放置Threading.sleep，但不会改变结果。

代码

    Private Sub btnDrawBmp_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Capture.Click
    ' Initialize new Hidden Browser control and navigate to site
    Dim Browser As New WebBrowser
    Browser.ScrollBarsEnabled = False
    Browser.Navigate("http://xxxxx/LiveStats/")
    ' Initialize Handler for DocumentCompleted event and wait for that event to fire
    AddHandler Browser.DocumentCompleted, AddressOf Browser_DocumentCompleted
    While Browser.ReadyState <> WebBrowserReadyState.Complete
        Application.DoEvents()
    End While
    ' Housekeeping
    Browser.Dispose()
End Sub
Private Sub Browser_DocumentCompleted(ByVal sender As Object, ByVal e As WebBrowserDocumentCompletedEventArgs)
    ' If sender was a WebBrowser then initialize a reference to it otherwise throw an exception
    Dim Browser As WebBrowser = DirectCast(sender, WebBrowser)
    ' Set browser start size, determine scrollheight, resize browser to match scrollheight
    Browser.ClientSize = New Size(1024, 768)
    Dim Height As Integer = Browser.Document.Body.ScrollRectangle.Bottom
    Browser.ClientSize = New Size(1024, Height)
    ' Initialize bitmap to match width & scrollheight for fullsize screen capture
    Dim Bmp = New Bitmap(Browser.Bounds.Width, Height)
    ' Capture fullsize screen shot
    Browser.DrawToBitmap(Bmp, Browser.Bounds)
    Bmp.Save("c:\temp1.png")
    ' Resize Browser for thumbnail capture
    Browser.ClientSize = New Size(1024, 768)
    ' Inialize a new bitmap with the same client area size as the browser
    Dim Bmp2 = New Bitmap(Browser.Bounds.Width, Browser.Bounds.Height)
    ' Perform screen capture, convert it to a thumbnail, and save
    Browser.DrawToBitmap(Bmp2, Browser.Bounds)
    Bmp2 = Bmp2.GetThumbnailImage(160, 120, Nothing, IntPtr.Zero)
    Bmp2.Save("c:\temp2.png")
    ' Housekeeping
    Bmp.Dispose()
    Bmp2.Dispose()
End Sub

更新了仍有问题的代码：

注意：表单上只有2个对象是按钮和浏览器。

Private Sub btnDrawBmp_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Capture.Click
    ' Initialize new Hidden Browser control and navigate to site
    'Dim Browser As New WebBrowser
    Dim Browser = wb
    Browser.ScrollBarsEnabled = False
    Browser.Navigate("http://ssgw8sr01/LiveStats/")
    'Browser.Navigate("http://google.com")
    ' Initialize Handler for DocumentCompleted event and wait for that event to fire
    AddHandler Browser.DocumentCompleted, AddressOf Browser_DocumentCompleted
    While Browser.ReadyState <> WebBrowserReadyState.Complete
        Application.DoEvents()
    End While
    ' Housekeeping
    Browser.Dispose()
End Sub
Private Sub Browser_DocumentCompleted(ByVal sender As Object, ByVal e As WebBrowserDocumentCompletedEventArgs)
    If (e.Url = wb.Url) AndAlso (wb.ReadyState = WebBrowserReadyState.Complete) Then
        ' If sender was a WebBrowser then initialize a reference to it otherwise throw an exception
        Dim Browser As WebBrowser = DirectCast(sender, WebBrowser)
        ' Set browser start size, determine scrollheight, resize browser to match scrollheight
        Browser.ClientSize = New Size(1024, 768)
        Dim Height As Integer = Browser.Document.Body.ScrollRectangle.Bottom
        Browser.ClientSize = New Size(1024, Height)
        ' Initialize bitmap to match width & scrollheight for fullsize screen capture
        Dim Bmp = New Bitmap(Browser.Bounds.Width, Height)
        ' Capture fullsize screen shot
        Browser.DrawToBitmap(Bmp, Browser.Bounds)
        Bmp.Save("c:\temp1.png")
        ' Resize Browser for thumbnail capture
        Browser.ClientSize = New Size(1024, 768)
        ' Inialize a new bitmap with the same client area size as the browser
        Dim Bmp2 = New Bitmap(Browser.Bounds.Width, Browser.Bounds.Height)
        ' Perform screen capture, convert it to a thumbnail, and save
        Browser.DrawToBitmap(Bmp2, Browser.Bounds)
        Bmp2 = Bmp2.GetThumbnailImage(160, 120, Nothing, IntPtr.Zero)
        Bmp2.Save("c:\temp2.png")
        ' Housekeeping
        Bmp.Dispose()
        Bmp2.Dispose()
    End If

End Sub

Answer 1

在doc_completed事件中添加此项，更改WB变量，我在手机上，这是PITA。

我认为您需要等待即时状态才能完成。

If (e.Url = wb.Url) AndAlso (wb.ReadyState = WebBrowserReadyState.Complete) Then
 ' If sender was a WebBrowser then initialize a reference to it otherwise throw an exception
    Dim Browser As WebBrowser = DirectCast(sender, WebBrowser)
    ' Set browser start size, determine scrollheight, resize browser to match scrollheight
    Browser.ClientSize = New Size(1024, 768)
    Dim Height As Integer = Browser.Document.Body.ScrollRectangle.Bottom
    Browser.ClientSize = New Size(1024, Height)
    ' Initialize bitmap to match width & scrollheight for fullsize screen capture
    Dim Bmp = New Bitmap(Browser.Bounds.Width, Height)
    ' Capture fullsize screen shot
    Browser.DrawToBitmap(Bmp, Browser.Bounds)
    Bmp.Save("c:\temp1.png")
    ' Resize Browser for thumbnail capture
    Browser.ClientSize = New Size(1024, 768)
    ' Inialize a new bitmap with the same client area size as the browser
    Dim Bmp2 = New Bitmap(Browser.Bounds.Width, Browser.Bounds.Height)
    ' Perform screen capture, convert it to a thumbnail, and save
    Browser.DrawToBitmap(Bmp2, Browser.Bounds)
    Bmp2 = Bmp2.GetThumbnailImage(160, 120, Nothing, IntPtr.Zero)
    Bmp2.Save("c:\temp2.png")
    ' Housekeeping
    Bmp.Dispose()
    Bmp2.Dispose()
End If

编辑：

这已经过测试，即使在缓慢加载的网站上也可以像魅力一样工作。在完全加载之前，它不会创建屏幕截图。

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        WebBrowser1.Navigate("http:\\www.msn.com")
    End Sub

    Private Sub WebBrowser1_DocumentCompleted(sender As Object, e As WebBrowserDocumentCompletedEventArgs) Handles WebBrowser1.DocumentCompleted
        If (e.Url = WebBrowser1.Url) AndAlso (WebBrowser1.ReadyState = WebBrowserReadyState.Complete) Then
            getBitmap(WebBrowser1).Save("C:\Users\Anthony Wiles\Desktop\myScreenShot.png")
        End If
    End Sub

    Private Function getBitmap(ByVal pCtrl As Control) As Drawing.Bitmap
        Dim myBmp As New Bitmap(pCtrl.Width, pCtrl.Height)
        Dim g As Graphics = Graphics.FromImage(myBmp)
        Dim pt As Point = pCtrl.Parent.PointToScreen(pCtrl.Location)
        g.CopyFromScreen(pt, Point.Empty, myBmp.Size)
        g.Dispose()
        Return myBmp
    End Function

添加延迟到网站截图

1 个答案: