GridView - InvalidCastException is thrown when exporting a Data Grid that contains conditional formatting rules

Hi Vladislav,

in my case it didn't work.
It cames up with:

Code
System.InvalidCastException

  Message=Invalid cast from 'Int32' to 'DateTime'.
  Source=System.Private.CoreLib

But after some investigations i found my own fault - even if the error did not occur with the FW-Version.

That's what i found aka what i'am doing wrong. I need to add columns dynamically to the grid. I need to set the format
BUT i also try to hide (make them invisible) numeric values when they containing value is 0 (zero).
BUT that's wrong and causes the exeption, when the format is a Date.

C#
if (!string.IsNullOrEmpty(format))
            {
            // did not work when the field is a date!!
                **FormatConditionRuleValue markRule = new FormatConditionRuleValue();
                markRule.Condition = FormatCondition.Equal;
                markRule.Value1 = 0;
                markRule.Appearance.ForeColor = Color.Transparent;
                Grid.FormatRules.Add(Grid.Columns[colName], markRule);**

                switch (format)
                {
                    case "d":
                        Grid.Columns[colName].DisplayFormat.FormatType = FormatType.DateTime;
                        markRule = new FormatConditionRuleValue();
                        markRule.Condition = FormatCondition.Equal;
                        markRule.Value1 = DateTime.MinValue;
                        markRule.Appearance.BackColor = Color.Transparent;
                        markRule.Appearance.ForeColor = Color.Transparent;
                        Grid.FormatRules.Add(Grid.Columns[colName], markRule);
                        break;

                    case "{0.0##0}":
                        Grid.Columns[colName].DisplayFormat.FormatType = FormatType.Numeric;
                        Grid.Columns[colName].DisplayFormat.FormatString = "0.0##0";

                        break;

                    case "{#,##0}":
                        Grid.Columns[colName].DisplayFormat.FormatType = FormatType.Numeric;
                        Grid.Columns[colName].DisplayFormat.FormatString = "#,##0";
                        Grid.Columns[colName].SummaryItem.Assign(new GridSummaryItem(SummaryItemType.Sum, colName, "{#,##0}"));
                        Grid.Columns[colName].AllowSummaryMenu = true;
                        break;

                    case "C2":
                        Grid.Columns[colName].DisplayFormat.FormatType = FormatType.Numeric;
                        Grid.Columns[colName].DisplayFormat.FormatString = "C2";
                        Grid.Columns[colName].SummaryItem.Assign(new GridSummaryItem(SummaryItemType.Sum, colName, "{0:C2}"));
                        Grid.Columns[colName].AllowSummaryMenu = true;
                        break;

                    default:

                        Grid.Columns[colName].DisplayFormat.FormatString = format;

                        break;
                }

Hello,

Could you modify the initial project you shared or create a new one to replicate this exception? I will check the cause of this behavior.

The hotfix 22.1.4 worked for me. Thank you.