The column background colour in my XamDataGrid keeps changing or to put it another way, beware the CellContainerGenerationMode when overriding the CellValuePresenterStyle.<\/p>\n
What’s the problem ?<\/strong><\/p>\n First off, please note I’m using v12.2 of Infragistics XamDataGrid, ofcourse this functionality may work differently in other versions of the control.<\/em><\/p>\n I’m still getting to grips with the Infragistics XamDataGrid. Whilst I know the old UltraGrid for WinForms pretty well, this is worthless experience when using the WPF XamDataGrid.<\/p>\n I was working on a way to highlight a “Reference” field\/column in the XamDataGrid and got this working nicely using a Converter with a CellValuePresenterStyle but whilst playing with the UI I notice that horizontally scrolling the grid demonstrated a very strange behaviour. Initially my reference column was displayed with a gray background (my chosen colour) but when I scroll it out of view and back into view, it turned white (the default background). Worse still another column went gray. Not the sort of functionality a customer\/user would want to see !<\/p>\n Let’s take a look at an example. <\/p>\n Note: this is a contrived example to demonstrate the issue, the code I was working on was more dynamic and the fields set-up in code behind, but I wanted to distill the example into it’s simplest components.<\/em><\/p>\n In this sample code I’m using a DataTable and a CellValuePresenterStyle (obviously this problem may not occur in different scenarios).<\/p>\n First up, let’s look at the sample data, we’re going to create enough columns to require us to horizontally scroll<\/p>\n Next up, let’s look at the XAML for the XamDataGrid<\/p>\n Next let’s look at style<\/p>\n and finally the converter<\/p>\n Now if you run up an example WPF Window with these parts and horizontally scroll you should see the gray background column switch from the E1 column to other columns.<\/p>\n A solution<\/strong><\/p>\n So I had a chat with a colleague who mentioned the grid’s virtualization options being a possible issue – lo and behold adding the CellContainerGenerationMode<\/strong> attribute and setting it to LazyLoad<\/strong> worked.<\/p>\n For example<\/p>\n It appears the XamDataGrid has a default value of Recycle for the CellContainerGenerationMode and an educated guess (based as much on the naming as anything) suggests this means the XamDataGrid is reusing the field\/column when scrolling – this is all well and good when your column styling is static, but not so good when you have something a little more dynamic. <\/p>\n\r\nvar dataTable = new DataTable();\r\ndataTable.Columns.Add("A1", typeof(int));\r\ndataTable.Columns.Add("B1", typeof(int));\r\ndataTable.Columns.Add("C1", typeof(int));\r\ndataTable.Columns.Add("D1", typeof(int));\r\ndataTable.Columns.Add("E1", typeof(int));\r\ndataTable.Columns.Add("F1", typeof(int));\r\ndataTable.Columns.Add("G1", typeof(int));\r\ndataTable.Columns.Add("H1", typeof(int));\r\ndataTable.Columns.Add("I1", typeof(int));\r\ndataTable.Columns.Add("J1", typeof(int));\r\ndataTable.Columns.Add("K1", typeof(int));\r\ndataTable.Columns.Add("L1", typeof(int));\r\ndataTable.Columns.Add("M1", typeof(int));\r\ndataTable.Columns.Add("N1", typeof(int));\r\n\r\nvar row1 = dataTable.NewRow();\r\nrow1["A1"] = 1;\r\nrow1["B1"] = 1;\r\nrow1["C1"] = 1;\r\nrow1["D1"] = 1;\r\nrow1["E1"] = 1;\r\nrow1["F1"] = 1;\r\nrow1["G1"] = 1;\r\nrow1["H1"] = 1;\r\nrow1["I1"] = 1;\r\nrow1["J1"] = 1;\r\nrow1["K1"] = 1;\r\nrow1["L1"] = 1;\r\nrow1["M1"] = 1;\r\nrow1["N1"] = 1;\r\ndataTable.Rows.Add(row1);\r\n\r\nvar row2 = dataTable.NewRow();\r\nrow2["A1"] = 2;\r\nrow2["B1"] = 2;\r\nrow2["C1"] = 2;\r\nrow2["D1"] = 2;\r\nrow2["E1"] = 2;\r\nrow2["F1"] = 2;\r\nrow2["G1"] = 2;\r\nrow2["H1"] = 2;\r\nrow2["I1"] = 2;\r\nrow2["J1"] = 2;\r\nrow2["K1"] = 2;\r\nrow2["L1"] = 2;\r\nrow2["M1"] = 2;\r\nrow2["N1"] = 2;\r\ndataTable.Rows.Add(row2);\r\n\r\nDataContext = dataTable;\r\n<\/pre>\n\r\n<igDP:XamDataGrid DataSource="{Binding}" >\r\n <igDP:XamDataGrid.FieldLayouts>\r\n <igDP:FieldLayout>\r\n <igDP:FieldLayout.Fields>\r\n <igDP:Field Name="A1" Label="A1">\r\n <igDP:Field.Settings>\r\n <igDP:FieldSettings CellValuePresenterStyle="{StaticResource CellValuePresenterStyle}"\/>\r\n <\/igDP:Field.Settings>\r\n <\/igDP:Field>\r\n <igDP:Field Name="B1" Label="B1">\r\n <igDP:Field.Settings>\r\n <igDP:FieldSettings CellValuePresenterStyle="{StaticResource CellValuePresenterStyle}"\/>\r\n <\/igDP:Field.Settings>\r\n <\/igDP:Field>\r\n <igDP:Field Name="B1" Label="B1">\r\n <igDP:Field.Settings>\r\n <igDP:FieldSettings CellValuePresenterStyle="{StaticResource CellValuePresenterStyle}"\/>\r\n <\/igDP:Field.Settings>\r\n <\/igDP:Field>\r\n <igDP:Field Name="C1" Label="C1">\r\n <igDP:Field.Settings>\r\n <igDP:FieldSettings CellValuePresenterStyle="{StaticResource CellValuePresenterStyle}"\/>\r\n <\/igDP:Field.Settings>\r\n <\/igDP:Field>\r\n <igDP:Field Name="D1" Label="D1">\r\n <igDP:Field.Settings>\r\n <igDP:FieldSettings CellValuePresenterStyle="{StaticResource CellValuePresenterStyle}"\/>\r\n <\/igDP:Field.Settings>\r\n <\/igDP:Field>\r\n <igDP:Field Name="E1" Label="E1">\r\n <igDP:Field.Settings>\r\n <igDP:FieldSettings CellValuePresenterStyle="{StaticResource CellValuePresenterStyle}"\/>\r\n <\/igDP:Field.Settings>\r\n <\/igDP:Field>\r\n <igDP:Field Name="F1" Label="F1">\r\n <igDP:Field.Settings>\r\n <igDP:FieldSettings CellValuePresenterStyle="{StaticResource CellValuePresenterStyle}"\/>\r\n <\/igDP:Field.Settings>\r\n <\/igDP:Field>\r\n <igDP:Field Name="G1" Label="G1">\r\n <igDP:Field.Settings>\r\n <igDP:FieldSettings CellValuePresenterStyle="{StaticResource CellValuePresenterStyle}"\/>\r\n <\/igDP:Field.Settings>\r\n <\/igDP:Field>\r\n <igDP:Field Name="G1" Label="G1">\r\n <igDP:Field.Settings>\r\n <igDP:FieldSettings CellValuePresenterStyle="{StaticResource CellValuePresenterStyle}"\/>\r\n <\/igDP:Field.Settings>\r\n <\/igDP:Field>\r\n <igDP:Field Name="H1" Label="H1">\r\n <igDP:Field.Settings>\r\n <igDP:FieldSettings CellValuePresenterStyle="{StaticResource CellValuePresenterStyle}"\/>\r\n <\/igDP:Field.Settings>\r\n <\/igDP:Field>\r\n <igDP:Field Name="I1" Label="I1">\r\n <igDP:Field.Settings>\r\n <igDP:FieldSettings CellValuePresenterStyle="{StaticResource CellValuePresenterStyle}"\/>\r\n <\/igDP:Field.Settings>\r\n <\/igDP:Field>\r\n <igDP:Field Name="J1" Label="J1">\r\n <igDP:Field.Settings>\r\n <igDP:FieldSettings CellValuePresenterStyle="{StaticResource CellValuePresenterStyle}"\/>\r\n <\/igDP:Field.Settings>\r\n <\/igDP:Field>\r\n <igDP:Field Name="K1" Label="K1">\r\n <igDP:Field.Settings>\r\n <igDP:FieldSettings CellValuePresenterStyle="{StaticResource CellValuePresenterStyle}"\/>\r\n <\/igDP:Field.Settings>\r\n <\/igDP:Field>\r\n <igDP:Field Name="L1" Label="L1">\r\n <igDP:Field.Settings>\r\n <igDP:FieldSettings CellValuePresenterStyle="{StaticResource CellValuePresenterStyle}"\/>\r\n <\/igDP:Field.Settings>\r\n <\/igDP:Field>\r\n <igDP:Field Name="M1" Label="M1">\r\n <igDP:Field.Settings>\r\n <igDP:FieldSettings CellValuePresenterStyle="{StaticResource CellValuePresenterStyle}"\/>\r\n <\/igDP:Field.Settings>\r\n <\/igDP:Field>\r\n <igDP:Field Name="N1" Label="N1">\r\n <igDP:Field.Settings>\r\n <igDP:FieldSettings CellValuePresenterStyle="{StaticResource CellValuePresenterStyle}"\/>\r\n <\/igDP:Field.Settings>\r\n <\/igDP:Field>\r\n <\/igDP:FieldLayout.Fields>\r\n <\/igDP:FieldLayout>\r\n <\/igDP:XamDataGrid.FieldLayouts>\r\n<\/igDP:XamDataGrid>\r\n<\/pre>\n\r\n<Style TargetType="{x:Type igDP:CellValuePresenter}" x:Key="CellValuePresenterStyle">\r\n <Setter Property="Background" \r\n Value="{Binding RelativeSource={RelativeSource Self}, \r\n Converter={StaticResource BackgroundConverter}}" \/>\r\n<\/Style>\r\n<\/pre>\n\r\npublic class BackgroundConverter : IValueConverter\r\n{\r\n public object Convert(object value, Type targetType, object parameter, CultureInfo culture)\r\n {\r\n var cellValuePresenter = value as CellValuePresenter;\r\n if (cellValuePresenter != null)\r\n {\r\n \/\/ in my code this is "discovered" at runtime, but you get the idea\r\n if (cellValuePresenter.Field.Name == "E1")\r\n return Brushes.Gray;\r\n }\r\n\r\n return Binding.DoNothing;\r\n }\r\n\r\n public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)\r\n {\r\n throw new NotImplementedException();\r\n }\r\n}\r\n<\/pre>\n\r\n<igDP:XamDataGrid DataSource="{Binding DefaultView}" CellContainerGenerationMode="LazyLoad">\r\n<\/pre>\n