使用 Excel interop 的应用程序仅收集和写入一次数据

Question

我编写了一个小型应用程序，它从 PLC 收集数据，然后将该数据写入 Excel。当我第一次打开应用程序收集数据时，它工作得很好，但是，如果我尝试再次收集，它不会将任何数据放入文件中，而只是在模板文件上另存为。如果我重新启动应用程序，它会再次工作，但只有 1 次。这是简化的代码。

    // Open the Excel application
    Excel.Application excel = new Excel.Application();
    // Open the workbook
    string filelocation = Properties.Settings.Default.templateLocation;
    Excel.Workbook workbook = excel.Workbooks.Open(filelocation);

    //Define the worksheet and open
    Excel.Worksheet sh =       (Microsoft.Office.Interop.Excel.Worksheet)workbook.Sheets["MULTIPLE_SHOT_DATA"];

    //Saves as dialog control to get filename and location
    SaveFileDialog saveFileDialog1 = new SaveFileDialog();
    if (Properties.Settings.Default.filedir != null || Properties.Settings.Default.filedir != "")
    {
        saveFileDialog1.InitialDirectory = Properties.Settings.Default.filedir;
    }

    saveFileDialog1.Filter = "Worksheet (*.xlsx)|*.xlsx|All Files (*.*)|*.*";
    saveFileDialog1.Title = "Save an Excel File";
    saveFileDialog1.ShowDialog();

    //Column loop should be 24 or 36 for different ball machines
    for (int columnloop = 0; columnloop < 24; columnloop++)
    {
        int inbounddata = columnloop;
        string inbounddatastring = inbounddata.ToString();
        _myItem.HWTagType = TagType.AUTO;
        _myItem.HWTagName = "Ball[" + inbounddatastring + ",0]";
        _myItem.Elements = 100;

        try
        {
            // Call Item.Read method
            _myItem.Read();

            // For atomic types, each Item.Values element represents one atomic value.
            if (!_myItem.Values[0].GetType().IsArray)
            {
                for (int i = 0; i < _myItem.Elements; i++)
            {
            int inboundcolumn = excelcolumn;
            fint = i + 1;
            sh.Cells[fint, inboundcolumn] = _myItem.Values[i];
        }

    }
    // For structured types (UDT, PDT, and System), each Item.Values element represents an array of    bytes
    else
    {
    }
}
catch (Exception ex)
{
    AddEvent("Error, Item.Quality is " + _myItem.Quality.ToString();
}
finally
{
this.Cursor = Cursors.Default;
}
}
}
//Save as and close active file
workbook.SaveAs(@Properties.Settings.Default.filename, Type.Missing, Type.Missing,
     Type.Missing, Type.Missing, Type.Missing, XlSaveAsAccessMode.xlNoChange,
     Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
Marshal.FinalReleaseComObject(sh);
workbook.Close();
Marshal.FinalReleaseComObject(workbook);

// Quit the Excel application
excel.Quit();
Marshal.FinalReleaseComObject(excel);

我希望这会多次起作用，但事实并非如此。

Answer 1

我认为您可能已将此代码放入已加载或开始事件中。为什么不创建一个按钮并向其中添加此代码呢？据我所知，它运行一次的原因是因为该代码位于被触发一次的事件中。