CODEWITHSUNDEEP
c#asp.netresponseexport-to-excel
Kartik Gaur
Kartik Gaur

Reputation: 33

processing of page stops after response.writefile

This question has been asked a number of times but still I am not able to find a proper solution to it. I have two questions.

I am creating an excel file, writing data to it and then rendering it to the user for download. I have used microsoft.interop for the same.

The first problem is: I am trying to use a messagebox(javascript) to show how many rows were generated in the excel file after the user has downloaded the excel. This messagebox never shows, however the code is executed. How can i achieve this?

Secondly: After the excel has been created, an excel.exe process keeps running in the task manager, even after i have manually cleaned up the references.

This alert box does not show after the file is rendered.

flag = WriteDatasetToExcel(ds);
            if (flag)
            {

                ClientScript.RegisterClientScriptBlock(GetType(), "Javascript", "<script>alert('Number of rows generated : " + ds.Tables[0].Rows.Count + "')</script>");
            }

The relevant code is given

excelApp = new Excel.Application();
        excelwrkbook = excelApp.Workbooks.Add(1);
        excelwrksheet = (Excel.Worksheet)excelwrkbook.Sheets[1];
        excelwrksheet.Name = "Application Data";

after writing data, saving and rendering is done like this:

excelwrkbook.SaveAs(filepath, Excel.XlFileFormat.xlWorkbookNormal, Missing.Value, Missing.Value, false, true, Excel.XlSaveAsAccessMode.xlNoChange, Excel.XlSaveConflictResolution.xlLocalSessionChanges, false, Missing.Value, Missing.Value, true);
        excelwrkbook.Close(0, 0, 0);
        HttpContext.Current.Response.Clear();
        HttpContext.Current.Response.Buffer = true;
        HttpContext.Current.Response.Charset = "";
        HttpContext.Current.Response.AddHeader("content-disposition", "attachment; filename=" + filename);
        HttpContext.Current.Response.ContentType = "application/vnd.ms-excel";
        HttpContext.Current.Response.WriteFile(filepath);
        excelApp.Quit();
        flag = true;

and now finally the cleanup code:

ReleaseObjects(excelrange);
        ReleaseObjects(excelwrksheet);
        ReleaseObjects(excelwrkbook);
        ReleaseObjects(excelApp);

the releaseobjects function is as follows:

private void ReleaseObjects(Object obj)
{
    if (obj != null && Marshal.IsComObject(obj))
    {
        while (System.Runtime.InteropServices.Marshal.ReleaseComObject(obj) != 0) { }

    }
}

Upvotes: 2

Views: 754

Answers (1)

AMember
AMember

Reputation: 3057

First of all let me tell you that working in a web based environment with Microsoft Excel interop is not very efficient.

I use usually use the openXML approach for this needs. here

for your first question: Your response content type is application/vnd.ms-excel hence the browser will not execute any java script from this content. you must identify that the excel has been downloaded or make a prior call to get the rows and return the result in a java script or any other acceptable content type.

for your second question: just don't use it for web environment it was not designed for it.

Upvotes: 1

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