Export exception

[Jerry]

Hi there,


I have implemented the export function for the grid. Well, sometime it works fine, but sometime when I open page, and first time click the Export, it gives an exception, but the second time click works fine. see attached picture.

Could you explain what's the cause for this problem and how do I prevent this to happen?



regards
Jerry

[Vlad]

Hello,

 You can check this thread for more info:
http://stackoverflow.com/questions/1355078/dialogs-must-be-user-initiated-with-savefiledialog-in-silverlight-3

Greetings,
Vlad
the Telerik team

[Jerry]

Hi Vlad,


Sorry about late reply. I don't think the link that you provided actually solve my problem.

Upon button click, I immediately show the popup which exactly as link described.

here is my button click event

private void SurveyCommandPanel_ExportClick(object sender, RoutedEventArgs e)
{
    CommonHelper.Export(SurveyAnswerGridView, ExportFormat.ExcelML);
}

Then following is the actualy Export method

public static void Export(GridViewDataControl grid, ExportFormat format)
{
    if (grid == null)
    {
        return;
    }

    if (format == ExportFormat.ExcelML || format == ExportFormat.Html)
    {
        grid.ElementExporting += (sender, e) =>
        {
            if (e.Format == ExportFormat.ExcelML)
            {
                if (e.Value != null && e.Value.GetType() == typeof(string))
                {
                    //e.ShouldEncodeValue = true;

                    bool shouldEncode = true;

                    foreach (var item in _specialChar)
                    {
                        if (e.Value.ToString().Contains(item))
                        {
                            shouldEncode = false;
                            break;
                        }
                    }

                    if (shouldEncode)
                    {
                        e.Value = HttpUtility.HtmlEncode((e.Value as string));
                    }
                }
            }
        };
    }

    string extension = string.Empty;

    switch (format)
    {
        case ExportFormat.ExcelML:
            extension = "xml";
            break;
        case ExportFormat.Html:
            extension = "doc";
            break;
        case ExportFormat.Csv:
            extension = "csv";
            break;
    }

    if (extension.IsNullOrEmpty())
    {
        throw new Exception("Unsuported ExportFormat, the extension can not be resolved.");
    }

    var dialog = new SaveFileDialog()
    {
        DefaultExt = extension,
        Filter = String.Format("{1} files (*.{0})|*.{0}|All files (*.*)|*.*", extension, format),
        FilterIndex = 1
    };

    if (dialog.ShowDialog() == true)
    {
        using (Stream stream = dialog.OpenFile())
        {
            grid.Export(stream,
             new GridViewExportOptions()
             {
                 Format = format,
                 ShowColumnHeaders = true,
                 ShowColumnFooters = true,
                 ShowGroupFooters = false,
             });
        }
    }
}

Well, could you tell me whats the problem could be?


regards
Jerry Ren