C#

private TabPage GetOrAddTabPage(string TabName, TabControl Control)
{
    foreach (TabPage item in tabControl1.TabPages)
    {
        if (item.Text == TabName) return item;
    }
    TabPage tab = new TabPage();
    RichTextBox document = new RichTextBox();
    document.Dock = DockStyle.Fill;
    document.ReadOnly = true;
    tab.Controls.Add(document);
    tab.Text = TabName;
    Control.TabPages.Add(tab);
    return tab;
}

// Here you come to the point where the user whose name is in the
// "UserName" variable received a message - you must get the
// corresponding tab or create a new one if it doesn't exist.
// "MyTabControl" is the tab control you created on your form.

TabPage UserPage = GetOrAddTabPage(UserName, MyTabControl);

// Now "UserPage" contains the user's tab page, and you can use it.

extendedDataTableObject.ToExcel(@"c:\test.xlsx");

Exception Occured While Generating Excel Document

Moreno Airoldi wrote:

As for opening the xls file, you will be able to do that safely once you call Close on it (on the corresponding Workbook object), so that won't be a problem. Smile

Microsoft.Office.Interop.Excel.Application myApp = null;
Microsoft.Office.Interop.Excel.Workbook myWorkbook = null;
try
{
    myApp = new Microsoft.Office.Interop.Excel.ApplicationClass();
    myApp.AskToUpdateLinks = false;
    myApp.DisplayAlerts = false;
    myWorkbook = myApp.Workbooks.Add(Microsoft.Office.Interop.Excel.XlWBATemplate.xlWBATWorksheet);
    myWorkbook.SaveAs("D:\\test.xls", Microsoft.Office.Interop.Excel.XlFileFormat.xlXMLSpreadsheet,
        System.Type.Missing, System.Type.Missing, false, false,
        Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlNoChange, System.Type.Missing,
        System.Type.Missing, System.Type.Missing, System.Type.Missing, System.Type.Missing);

}
catch (Exception ex)
{
    MessageBox.Show(ex.Message, "ERROR", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
finally
{
    if (myWorkbook != null)
    {
        myWorkbook.Close(false, "", null);
        myWorkbook = null;
    }
    if (myApp != null)
    {
        myApp.Quit();
        myApp = null;
    }
}

System.Diagnostics.Process.Start("D:\\test.xls");

Microsoft.Office.Interop.Excel.Application myApp = null;
Microsoft.Office.Interop.Excel.Workbook myWorkbook = null;
try
{
    try
    {
        myApp = new Microsoft.Office.Interop.Excel.ApplicationClass();
        myApp.Visible = true;
        myApp.AskToUpdateLinks = false;
        myApp.DisplayAlerts = false;
        myWorkbook = myApp.Workbooks.Add(Microsoft.Office.Interop.Excel.XlWBATemplate.xlWBATWorksheet);
        myWorkbook.SaveAs("D:\\test.xls", Microsoft.Office.Interop.Excel.XlFileFormat.xlXMLSpreadsheet,
            System.Type.Missing, System.Type.Missing, false, false,
            Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlNoChange, System.Type.Missing,
            System.Type.Missing, System.Type.Missing, System.Type.Missing, System.Type.Missing);

    }
    finally
    {
        if (myWorkbook != null)
        {
            myWorkbook.Close(false, "", null);
            myWorkbook = null;
        }
    }

    System.Threading.Thread.Sleep(3000);
    System.Diagnostics.Process.Start("D:\\test.xls");
    System.Threading.Thread.Sleep(3000);
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message, "ERROR", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
finally
{
    if (myApp != null)
    {
        myApp.Quit();
        myApp = null;
    }
}

for (int i = 1; i < 6; i++)
{
    Microsoft.Office.Interop.Excel.Application myApp = null;
    Microsoft.Office.Interop.Excel.Workbook myWorkbook = null;
    try
    {
        try
        {
            myApp = new Microsoft.Office.Interop.Excel.ApplicationClass();
            myApp.Visible = true;
            myApp.AskToUpdateLinks = false;
            myApp.DisplayAlerts = false;
            myWorkbook = myApp.Workbooks.Add(Microsoft.Office.Interop.Excel.XlWBATemplate.xlWBATWorksheet);
            myWorkbook.SaveAs("D:\\test" + i.ToString() + ".xls", Microsoft.Office.Interop.Excel.XlFileFormat.xlXMLSpreadsheet,
                System.Type.Missing, System.Type.Missing, false, false,
                Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlNoChange, System.Type.Missing,
                System.Type.Missing, System.Type.Missing, System.Type.Missing, System.Type.Missing);

        }
        finally
        {
            if (myWorkbook != null)
            {
                myWorkbook.Close(false, "", null);
                myWorkbook = null;
            }
            if (myApp != null)
            {
                myApp.Quit();
                myApp = null;
            }
        }

        System.Diagnostics.Process.Start("D:\\test" + i.ToString() + ".xls");
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message, "ERROR", MessageBoxButtons.OK, MessageBoxIcon.Error);
    }
}

Harry666 wrote:

I inserted the line GC.Collect() and now it works fin