绘制WebBrowser控件位图

Question

我尝试使用下面的代码（VB.net）保存面板控制为位图：

Private Sub SaveFileDialog1_FileOk(ByVal sender As System.Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles SaveFileDialog1.FileOk 
    filename = SaveFileDialog1.FileName 
    Dim CardImg As New Bitmap(Panel1.Width, Panel1.Height) 
    Panel1.DrawToBitmap(CardImg, Panel1.ClientRectangle) 
    CardImg.Save(filename, System.Drawing.Imaging.ImageFormat.Bmp) 
End Sub 

一切正常，除了Web浏览器控件，这是停靠在面板上。在保存的位图中，此控件仅显示为空白，而面板中的其他所有内容都呈现良好。有任何想法吗？

Answer 1

从http://www.vbforums.com/showthread.php?t=385497下载“ScreenCapture.vb”， 使用CaptureDeskTopRectangle，但你不应该用你的面板的位置，因为它 参考面板家长，你应该使用yourpanel.PointToScreen()识别正确 矩形。 问候..

UPDATE：

检查了这一点，你会去喜欢它，我similute你的情况下，它的工作：

Private Sub btnBrowse_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnBrowse.Click 
     Try 
      Using fl As New SaveFileDialog 
       fl.Filter = "PNG images|*.png" 
       If fl.ShowDialog = Windows.Forms.DialogResult.OK Then 
        Dim sc As New screencapture 
        Dim pt = WebBrowser1.Parent.PointToScreen(WebBrowser1.Location) 
        Dim rec As New Rectangle(pt.X, pt.Y, WebBrowser1.Width, WebBrowser1.Height) 
        Application.DoEvents() 
        Threading.Thread.Sleep(500) 
        Using bmp As Bitmap = sc.CaptureDeskTopRectangle(rec, WebBrowser1.Width, WebBrowser1.Height) 
         bmp.Save(fl.FileName, System.Drawing.Imaging.ImageFormat.Png) 
        End Using 
       End If 
      End Using 
     Catch ex As Exception 
      MsgBox(ex.Message) 
     End Try 
    End Sub 

更新2：

在形式：

Private Sub btnBrowse_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnBrowse.Click 
     Try 
      Using fl As New SaveFileDialog 
       fl.Filter = "PNG images|*.png" 
       If fl.ShowDialog = Windows.Forms.DialogResult.OK Then 
        JSsetTimeout.SetTimeout(Me, "TakeShot", 1500, fl.FileName) 
       End If 
      End Using 
     Catch ex As Exception 
      MsgBox(ex.Message) 
     End Try 
End Sub 

Sub TakeShot(ByVal FilePath As String) 
     Try 
      Application.DoEvents() 
      Dim sc As New screencapture 
      Dim pt = WebBrowser1.Parent.PointToScreen(WebBrowser1.Location) 
      Dim rec As New Rectangle(pt.X, pt.Y, WebBrowser1.Width, WebBrowser1.Height) 
      Using bmp As Bitmap = sc.CaptureDeskTopRectangle(rec, WebBrowser1.Width, WebBrowser1.Height) 
       bmp.Save(FilePath, System.Drawing.Imaging.ImageFormat.Png) 
      End Using 
     Catch ex As Exception 
      MsgBox(ex.Message) 
     End Try 
End Sub 

创建一个时间延迟添加下面的类：

Public Class JSsetTimeout 

    Public res As Object = Nothing 
    Dim WithEvents tm As Timer = Nothing 
    Dim _MethodName As String 
    Dim _args() As Object 
    Dim _ClassInstacne As Object = Nothing 

    Public Shared Sub SetTimeout(ByVal ClassInstacne As Object, ByVal obj As String, ByVal TimeSpan As Integer, ByVal ParamArray args() As Object) 
     Dim jssto As New JSsetTimeout(ClassInstacne, obj, TimeSpan, args) 
    End Sub 

    Public Sub New(ByVal ClassInstacne As Object, ByVal obj As String, ByVal TimeSpan As Integer, ByVal ParamArray args() As Object) 
     If obj IsNot Nothing Then 
      _MethodName = obj 
      _args = args 
      _ClassInstacne = ClassInstacne 
      tm = New Timer With {.Interval = TimeSpan, .Enabled = False} 
      AddHandler tm.Tick, AddressOf tm_Tick 
      tm.Start() 
     End If 
    End Sub 

    Private Sub tm_Tick(ByVal sender As Object, ByVal e As System.EventArgs) Handles tm.Tick 
     tm.Stop() 
     RemoveHandler tm.Tick, AddressOf tm_Tick 
     If Not String.IsNullOrEmpty(_MethodName) AndAlso _ClassInstacne IsNot Nothing Then 
      res = CallByName(_ClassInstacne, _MethodName, CallType.Method, _args) 
     Else 
      res = Nothing 
     End If 
    End Sub 
End Class 

Answer 2

当我浏览保存后从WebBrowser我打电话就可以了.Focus()快照 - 不知何故白色画面产生神奇disapperard。不知道为什么，但它对我有效。