vb.net代码捕获Word文档首页的屏幕截图

Question

您好，下面是可以捕获PNG格式的Word文档首页图像的步骤。 如果用户需要以任何其他格式捕获图像。 然后，在下面的代码中，将图像扩展名替换为所需的输出图像扩展名。 如果这个答案有用，那么别忘了投票。

Answer 1

第一步：首先，您需要在项目的名称空间下导入/引用：

    Import Imports Microsoft.Office.Interop.Word

第二步：在项目中添加空白类文件，然后将以下vb.net代码复制到Word文档中：

Public Class ClipboardAPI
<Runtime.InteropServices.DllImport("user32.dll", EntryPoint:="OpenClipboard", SetLastError:=True, ExactSpelling:=True, CallingConvention:=System.Runtime.InteropServices.CallingConvention.StdCall)> _
Public Shared Function OpenClipboard(ByVal hWnd As IntPtr) As Boolean
End Function

<Runtime.InteropServices.DllImport("user32.dll", EntryPoint:="EmptyClipboard", SetLastError:=True, ExactSpelling:=True, CallingConvention:=System.Runtime.InteropServices.CallingConvention.StdCall)> _
Public Shared Function EmptyClipboard() As Boolean
End Function

<Runtime.InteropServices.DllImport("user32.dll", EntryPoint:="SetClipboardData", SetLastError:=True, ExactSpelling:=True, CallingConvention:=System.Runtime.InteropServices.CallingConvention.StdCall)> _
Public Shared Function SetClipboardData(ByVal uFormat As Integer, ByVal ByValhWnd As IntPtr) As IntPtr
End Function

<Runtime.InteropServices.DllImport("user32.dll", EntryPoint:="CloseClipboard", SetLastError:=True, ExactSpelling:=True, CallingConvention:=System.Runtime.InteropServices.CallingConvention.StdCall)> _
Public Shared Function CloseClipboard() As Boolean
End Function

<Runtime.InteropServices.DllImport("user32.dll", EntryPoint:="GetClipboardData", SetLastError:=True, ExactSpelling:=True, CallingConvention:=System.Runtime.InteropServices.CallingConvention.StdCall)> _
Public Shared Function GetClipboardData(ByVal uFormat As Integer) As IntPtr
End Function

<Runtime.InteropServices.DllImport("user32.dll", EntryPoint:="IsClipboardFormatAvailable", SetLastError:=True, ExactSpelling:=True, CallingConvention:=System.Runtime.InteropServices.CallingConvention.StdCall)> _
Public Shared Function IsClipboardFormatAvailable(ByVal uFormat As Integer) As Short
End Function
End Class

第三步：这是仅从第一页从Word文档捕获图像的代码。

    Dim Width, Height, Orientation as Integer
    Dim objWord As New Microsoft.Office.Interop.Word.Application
    Dim objDoc As Microsoft.Office.Interop.Word.Document

    Const CF_ENHMETAFILE As Integer = 14
    objDoc = objWord.Documents.Open(YourSourcePath)

    objWord.ActiveDocument.Select()
    objWord.Selection.CopyAsPicture()

    Try
        Dim ip As IntPtr
        Dim metaFile As System.Drawing.Imaging.Metafile
        Dim bRet As Boolean
        bRet = ClipboardAPI.OpenClipboard(Me.Handle)
        If bRet = True Then
            'Verify the clipboard contains data available
            'as an enhanced metafile.
            bRet = ClipboardAPI.IsClipboardFormatAvailable(CF_ENHMETAFILE) <> 0
        End If

        If bRet = True Then
            'Store the clipboard's contents in the IntPtr.
            ip = ClipboardAPI.GetClipboardData(CF_ENHMETAFILE)
        End If

        'Verify the IntPrt contains data before proceeding. Passing
        'an empty IntPtr to System.Drawing.Imaging.Metafile results
        'in an exception.
        If Not IntPtr.Zero.Equals(ip) Then
            metaFile = New System.Drawing.Imaging.Metafile(ip, True)
            ClipboardAPI.CloseClipboard()
            Dim image As System.Drawing.Image = metaFile
            'Me.PictureBox1.Image = metaFile

            Dim objImageWriter As Image = New Bitmap(image)
            Dim objGraphics As Graphics = Graphics.FromImage(objImageWriter)
            objGraphics.Clear(Color.White)
            objGraphics.SmoothingMode = Drawing2D.SmoothingMode.AntiAlias

            If Orientation = 1 Then
                Width = image.Width
                Height = image.Height
            Else
                Width = image.Height
                Height = image.Width
            End If

            objGraphics.DrawImage(image, 0, 0, Width, Height)

            image.Dispose()
            objGraphics.Dispose()

            Dim ep As Imaging.EncoderParameters = New Imaging.EncoderParameters
            ep.Param(0) = New System.Drawing.Imaging.EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 100)

            Dim codecs() As Imaging.ImageCodecInfo = Imaging.ImageCodecInfo.GetImageEncoders()
            Dim iciInfo As Imaging.ImageCodecInfo
            Dim item As Imaging.ImageCodecInfo

            For Each item In codecs
                If (item.MimeType = "image/png") Then iciInfo = item
            Next

            ImageFileName = Format(Now, "ddMMMyyyy_hhmmss_") & RandNumber.Next & ".png"
            ImageFilePath = Application.StartupPath & "\" & ImageFileName
            objImageWriter.Save(ImageFilePath, iciInfo, ep)
            objImageWriter.Dispose()

        End If
    Catch ex As Exception
        ExceptionGenerated = True
        Throw New System.Exception(ex.Message.ToString())
    Finally
        objDoc.Close()
        objWord.Application.Quit(False)
        objDoc = Nothing
        objWord = Nothing
        ReleaseComObject(objWord)
        ReleaseComObject(objDoc)
    End Try

第四步：在项目中添加ReleaseComObject函数：

    Public Sub ReleaseComObject(ByVal obj As Object)
        Try
            System.Runtime.InteropServices.Marshal.ReleaseComObject(obj)
            obj = Nothing
        Catch ex As Exception
            obj = Nothing
        End Try
    End Sub

您甚至可以使用以下vb.net代码检查单词页面的方向：

    objDoc.PageSetup.Orientation = Microsoft.Office.Interop.Word.WdOrientation.wdOrientPortrait / wdOrientLandscape