Using Telerik Export the data grid value into excel.

[John]

Summarize the problem:  In the WPF grid, data is displayed using value converters (IValueConverter). When exporting with TelerikDataGrid.Export(), Telerik uses the raw bound values instead of the converted display values. This causes a mismatch: what you see in the grid is different from what appears in the exported Excel file.

Tried Method: 
Identified the root cause of the issue, the grid shows converted values (via IValueConverter). 
But after export uses raw bound values, will exported.  I need to export the Grid displayed value into the Excel.

M_DataGrid_ElementExporting

private void M_DataGrid_ElementExporting(object sender, Telerik.Windows.Controls.GridViewElementExportingEventArgs e)
        {
            if (e.Element == Telerik.Windows.Controls.ExportElement.Cell)
            {
                var cellExportingArgs = e as GridViewCellExportingEventArgs;

                if (e.Context is Telerik.Windows.Controls.GridViewDataColumn dataColumn)
                {
                    var col = e.Context as Telerik.Windows.Controls.GridViewDataColumn;
                    if (col != null && col.UniqueName == "MomentOfInertia")
                    {

                        var binding = dataColumn.DataMemberBinding;
                        var propertyValue = TelerikDataVis_Doc.GetPropertyValue(e.DataContext, binding.Path.Path);
                        if (binding != null)
                        {
                            object rawValue = e.Value;

                            if (binding.Converter != null)
                            {
                                rawValue = binding.Converter.Convert(
                                    propertyValue,
                                    typeof(string),
                                    binding.ConverterParameter,
                                    System.Globalization.CultureInfo.CurrentCulture);
                            }

                            if (!string.IsNullOrEmpty(binding.StringFormat))
                            {
                                e.Value = string.Format(binding.StringFormat, rawValue);
                            }
                            else
                            {
                                e.Value = rawValue?.ToString();
                            }
                        }
                    }
                }
            }
        }

[Martin Ivanov]

Hello John,

This behavior occurs because of how the data engine of RadGridView works. Basically, if you use IValueConverter with the DataMemberBinding of the columns, the converter value will be used only as a display value. All other data operations (sorting, filtering, etc.) will use the raw value. This includes the export of the data too.

To achieve your requirement, you can use the ElementExporting event and adjust the final value, as you are already doing.

If you use the ExportToXlsx method (which is the recommended one), you can use the ElementExportingToDocument event.

Regards,
Martin Ivanov
Progress Telerik