Peter's Gekko

Crystal Reports is a welcome subjects for blog posts. I still do like the product, my users are very happy with the results, the report editor is not that bad to work with and the components integrate well into a solution. But Crystal documentation is an absolute disaster. I wanted to add some functionality to my basic export routine. The only thing was adding export to Excel and to html. This functionality is present in the basic Crystal installation but how to use it is something which took me really a lot of Googling. The answers were not on the Crystal site but in the dungeons of the usenet. Let me share what I found.

On of the things I learned is that you have to Close() a report after exporting. This was not in the official Crystal example. I havn't measured the effect but it doesn't harm.

Exporting to Excel turned out to be just a matter of setting the right content type. This type turned out to be application/vnd.ms-excel. I had expected application/msexcel, as a nice sibling to application/msword. Exporting to Excel has some extra format options but you can do without them for a basic export. I'll leave these for another post.

To get the exporting to html to work took some things which are next to ridiculous, but I got it working. You have to set some format options. In these options you set the root directory and the filename. This directory-filename pair should be identical to the export filename passed to the report. The result will be an html formatted report, but in a "slightly" different location. To find the result you have to do some tricks. When Crystals creates a report is does create a temporary .rpt file. This file is stored in the windows\temp dir, it's name is a guid. When Crystal creates the exported report it creates a directory in the root directory supplied with the name of this guid. In this directory the report will be created, using the filename supplied. Thank goodness the name of the temporary file is available in the FilePath property of the report. This snippet demonstrates the workaround:

string[] fp = selectedReport.FilePath.Split("\\".ToCharArray());
string leafDir = fp[fp.Length-1];
// strip .rpt extension
leafDir = leafDir.Substring(0, leafDir.Length - 4);
tempFileNameUsed = string.Format("{0}{1}\\{2}", tempDir, leafDir, tempFileName);

To sum it all up :

protected void exportReport(CrystalDecisions.CrystalReports.Engine.ReportClass selectedReport, CrystalDecisions.Shared.ExportFormatType eft)
{
    selectedReport.ExportOptions.ExportFormatType = eft;

    string contentType ="";
    // Make sure asp.net has create and delete permissions in the directory
    string tempDir = System.Configuration.ConfigurationSettings.AppSettings["TempDir"];
    string tempFileName = Session.SessionID.ToString() + ".";
    switch (eft)
    {
    case CrystalDecisions.Shared.ExportFormatType.PortableDocFormat :
        tempFileName += "pdf";
        contentType = "application/pdf";
        break;
    case CrystalDecisions.Shared.ExportFormatType.WordForWindows :
        tempFileName+= "doc";
        contentType = "application/msword";
        break;
    case CrystalDecisions.Shared.ExportFormatType.Excel :
        tempFileName+= "xls";
        contentType = "application/vnd.ms-excel";
        break;
    case CrystalDecisions.Shared.ExportFormatType.HTML32 :
    case CrystalDecisions.Shared.ExportFormatType.HTML40 :
        tempFileName+= "htm";
        contentType = "text/html";
        CrystalDecisions.Shared.HTMLFormatOptions hop = new CrystalDecisions.Shared.HTMLFormatOptions();
        hop.HTMLBaseFolderName = tempDir;
        hop.HTMLFileName = tempFileName;
        selectedReport.ExportOptions.FormatOptions = hop;
        break;
    }

    CrystalDecisions.Shared.DiskFileDestinationOptions dfo = new CrystalDecisions.Shared.DiskFileDestinationOptions();
    dfo.DiskFileName = tempDir + tempFileName;
    selectedReport.ExportOptions.DestinationOptions = dfo;
    selectedReport.ExportOptions.ExportDestinationType = CrystalDecisions.Shared.ExportDestinationType.DiskFile;

    selectedReport.Export();
    selectedReport.Close();

    string tempFileNameUsed;
    if (eft == CrystalDecisions.Shared.ExportFormatType.HTML32 || eft == CrystalDecisions.Shared.ExportFormatType.HTML40)
    {
        string[] fp = selectedReport.FilePath.Split("\\".ToCharArray());
        string leafDir = fp[fp.Length-1];
        // strip .rpt extension
        leafDir = leafDir.Substring(0, leafDir.Length - 4);
        tempFileNameUsed = string.Format("{0}{1}\\{2}", tempDir, leafDir, tempFileName);
    }
    else
        tempFileNameUsed = tempDir + tempFileName;

    Response.ClearContent();
    Response.ClearHeaders();
    Response.ContentType = contentType;

    Response.WriteFile(tempFileNameUsed);
    Response.Flush();
    Response.Close();

    System.IO.File.Delete(tempFileNameUsed);
}

Which is pretty straightforward and even works. With a lot of thanks to the many people on the web who have also been strugling with this.

Peter