在c#中添加水印图像

取自http://social.msdn.microsoft.com/Forums/en-NZ/vbinterop/thread/2c8689e4-4f8c-42c1-b092-f8ae41b9779c

当您第一次以编程方式启动Word时，它会通过RPC服务器连接到Word。关闭文档时，此服务器将在应用程序不知情的情况下关闭。解决方案是捕获错误并重新初始化Word对象。然后你就可以继续了。

编辑：

您在外部初始化oWord对象，并且只初始化一次。然后在第一次运行中，在foreach循环中对其调用.Quit（）方法，之后该方法将不再可用。您将不得不删除BtnInserirImagem_Click中的oWord.Quit();，并使用一个不断初始化的单词对象，或者您可以在需要时初始化它，然后对它调用quit。

    Document wordFile = new Document();
    //OTHER VARIABLES
    Object oClassType = "Word.Document.8";
    Object oTrue = true;
    Object oFalse = false;
    Object oMissing = System.Reflection.Missing.Value;
    private void BtnInserirImagem_Click(object sender, RoutedEventArgs e)
    {
        //Init Word App Object here
        Microsoft.Office.Interop.Word.Application oWord = new Microsoft.Office.Interop.Word.Application();
        foreach (MyDocsList row in dataGridList.Items)
        {
            wordFile = oWord.Documents.Open(row.filename);
            //pass the Word App instance
            addWatermark(wordFile, row.filename, oWord);
        }
        // Quitting oWord outside of the loop
        oWord.Quit(ref oMissing, ref oMissing, ref oMissing);
    }
    //added the Word App instance to the signature
    private void addWatermark(Document doc, object filename, Microsoft.Office.Interop.Word.Application oWord)
    {
        object refmissing = System.Reflection.Missing.Value;
        string watermarkPath = Directory.GetCurrentDirectory() + "''fundo.jpg";
        if (File.Exists(watermarkPath))
        {
            object linkToFile = false;
            object saveWithDocument = true;
            WdHeaderFooterIndex hfIndex = WdHeaderFooterIndex.wdHeaderFooterPrimary;
            HeaderFooter headerFooter;
            for (int i = 1; i < doc.Sections.Count + 1; i++)
            {
                if (doc.Sections[i].Headers != null)
                {
                    headerFooter = doc.Sections[i].Headers[hfIndex];
                }
                else if (doc.Sections[i].Footers != null)
                {
                    headerFooter = doc.Sections[i].Footers[hfIndex];
                }
                else
                {
                    headerFooter = null;
                }
                if (headerFooter != null)
                {
                    try
                    {
                        Microsoft.Office.Interop.Word.Shape watermarkShape;
                        watermarkShape = headerFooter.Shapes.AddPicture(watermarkPath, ref linkToFile, ref saveWithDocument, ref refmissing,
                                                                        ref refmissing, ref refmissing, ref refmissing, ref refmissing);
                        watermarkShape.Left = Convert.ToSingle(WdShapePosition.wdShapeLeft);
                        watermarkShape.Top = Convert.ToSingle(WdShapePosition.wdShapeCenter);
                    }
                    catch (System.Runtime.InteropServices.COMException e)
                    {
                        MessageBoxResult result = MessageBox.Show(String.Format("{0} - Error Code = {1}", e.Message, e.ErrorCode));
                        throw e;
                    }
                }
            }
            oWord.ActiveWindow.View.SeekView = WdSeekView.wdSeekMainDocument;
            oWord.ActiveWindow.ActivePane.View.Type = Microsoft.Office.Interop.Word.WdViewType.wdPrintView;
        }
        else
        {
            MessageBoxResult result = MessageBox.Show("Could not find watermark image");
        }
        //THE LOCATION WHERE THE FILE NEEDS TO BE SAVED
        string outstringFile = "";
        string pathfile = System.IO.Path.GetDirectoryName(filename);
        string filenameFile = System.IO.Path.GetFileName(filename);
        outstringFile = pathfile + "''OG" + filenameFile;
        Object oSaveAsFile = (Object)(outstringFile);
        wordFile.SaveAs(ref oSaveAsFile, ref oMissing, ref oMissing, ref oMissing,
            ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing,
            ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing,
            ref oMissing, ref oMissing);
        //CLOSING THE FILE
        wordFile.Close(ref oFalse, ref oMissing, ref oMissing);
    }