Export Word document Error: The process cannot access the file because it is being used by another process

Hi tanws8,

Please refer below sample.

HTML

<asp:Button Text="Open" runat="server" OnClick="Open" />

Namespaces

C#

using System.IO;
using Microsoft.Office.Interop.Word;

VB.Net

Imports System.IO
Imports Microsoft.Office.Interop.Word

Code

C#

protected void Open(object sender, EventArgs e)
{
    string str_fileName = "A";
    int int_value = 0;
    object obj_missing = System.Reflection.Missing.Value;
    Microsoft.Office.Interop.Word._Application oWord = new Application();
    var word_doc = oWord.Documents.Add();
    if (int_value == 0)
    {
        if (!Directory.Exists(Server.MapPath("~/Files/")))
        {
            Directory.CreateDirectory(Server.MapPath("~/Files/"));
        }
        word_doc.SaveAs(Server.MapPath("~/Files/") + str_fileName + ".doc", WdSaveFormat.wdFormatDocument, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing);
        string pdfPath = Server.MapPath("~/Files/") + str_fileName + ".doc";
        byte[] bytes;
        FileStream fs = File.Open(pdfPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
        bytes = new byte[fs.Length];
        fs.Read(bytes, 0, Convert.ToInt32(fs.Length));
        fs.Close();
        word_doc.Close();
        if (File.Exists(pdfPath))
        {
            File.Delete(pdfPath);
        }
        Response.Clear();
        Response.Buffer = true;
        Response.Charset = "";
        Response.Cache.SetCacheability(HttpCacheability.NoCache);
        Response.ContentType = "application/octet-stream";
        Response.AddHeader("Content-Disposition", "attachment;filename=" + str_fileName + ".doc");
        Response.BinaryWrite(bytes);
        Response.Flush();
        Response.End();
    }
    else
    {
        if (!Directory.Exists(Server.MapPath("~/Files/")))
        {
            Directory.CreateDirectory(Server.MapPath("~/Files/"));
        }
        word_doc.SaveAs(Server.MapPath("~/Files/") + str_fileName + ".pdf", WdSaveFormat.wdFormatPDF, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing);
        string pdfPath = Server.MapPath("~/Files/") + str_fileName + ".pdf";
        FileStream fs = File.Open(pdfPath, FileMode.Open);
        byte[] bytes = new byte[fs.Length];
        fs.Read(bytes, 0, Convert.ToInt32(fs.Length));
        fs.Close();
        if (File.Exists(pdfPath))
        {
            File.Delete(pdfPath);
        }
        Response.Clear();
        Response.Buffer = true;
        Response.Charset = "";
        Response.Cache.SetCacheability(HttpCacheability.NoCache);
        Response.ContentType = "application/octet-stream";
        Response.AddHeader("Content-Disposition", "attachment;filename=" + str_fileName + ".pdf");
        Response.BinaryWrite(bytes);
        Response.Flush();
        Response.End();
    }
    ((Microsoft.Office.Interop.Word._Document)word_doc).Close(ref obj_missing, ref obj_missing, ref obj_missing);
    ((Microsoft.Office.Interop.Word._Application)oWord).Quit();
    oWord = null;
}

VB.Net

Protected Sub Open(ByVal sender As Object, ByVal e As EventArgs)
    Dim str_fileName As String = "A"
    Dim int_value As Integer = 0
    Dim obj_missing As Object = System.Reflection.Missing.Value
    Dim oWord As Microsoft.Office.Interop.Word._Application = New Application()
    Dim word_doc = oWord.Documents.Add()

    If int_value = 0 Then
        If Not Directory.Exists(Server.MapPath("~/Files/")) Then
            Directory.CreateDirectory(Server.MapPath("~/Files/"))
        End If
        word_doc.SaveAs(Server.MapPath("~/Files/") & str_fileName & ".doc", WdSaveFormat.wdFormatDocument, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing)
        Dim pdfPath As String = Server.MapPath("~/Files/") & str_fileName & ".doc"
        Dim bytes As Byte()
        Dim fs As FileStream = File.Open(pdfPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)
        bytes = New Byte(fs.Length - 1) {}
        fs.Read(bytes, 0, Convert.ToInt32(fs.Length))
        fs.Close()
        word_doc.Close()
        If File.Exists(pdfPath) Then
            File.Delete(pdfPath)
        End If
        Response.Clear()
        Response.Buffer = True
        Response.Charset = ""
        Response.Cache.SetCacheability(HttpCacheability.NoCache)
        Response.ContentType = "application/octet-stream"
        Response.AddHeader("Content-Disposition", "attachment;filename=" & str_fileName & ".doc")
        Response.BinaryWrite(bytes)
        Response.Flush()
        Response.End()
    Else

        If Not Directory.Exists(Server.MapPath("~/Files/")) Then
            Directory.CreateDirectory(Server.MapPath("~/Files/"))
        End If
        word_doc.SaveAs(Server.MapPath("~/Files/") & str_fileName & ".pdf", WdSaveFormat.wdFormatPDF, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing, obj_missing)
        Dim pdfPath As String = Server.MapPath("~/Files/") & str_fileName & ".pdf"
        Dim fs As FileStream = File.Open(pdfPath, FileMode.Open)
        Dim bytes As Byte() = New Byte(fs.Length - 1) {}
        fs.Read(bytes, 0, Convert.ToInt32(fs.Length))
        fs.Close()
        If File.Exists(pdfPath) Then
            File.Delete(pdfPath)
        End If
        Response.Clear()
        Response.Buffer = True
        Response.Charset = ""
        Response.Cache.SetCacheability(HttpCacheability.NoCache)
        Response.ContentType = "application/octet-stream"
        Response.AddHeader("Content-Disposition", "attachment;filename=" & str_fileName & ".pdf")
        Response.BinaryWrite(bytes)
        Response.Flush()
        Response.End()
    End If

    CType(word_doc, Microsoft.Office.Interop.Word._Document).Close(obj_missing, obj_missing, obj_missing)
    CType(oWord, Microsoft.Office.Interop.Word._Application).Quit()
    oWord = Nothing
End Sub

Screenshot