But beware that this will target ALL your cells (you're aiming at all the objects of type DataGridCell )
If you want to put a style according to the cell type, I'd recommend you to use a DataTemplateSelector
A good example can be found in Christian Mosers' DataGrid tutorial:
If you try to set the DataGrid.CellStyle the DataContext will be the row, so if you want to change the colour based on one cell it might be easiest to do so in specific columns, especially since columns can have varying contents, like TextBlocks, ComboBoxes and CheckBoxes. Here is an example of setting all the cells light-green where the Name is John:
Yet another option is to directly bind the Background to a property which returns the respectively coloured brush. You will have to fire property change notifications in the setters of properties on which the colour is dependent.
e.g.
public string Name
{
get { return _name; }
set
{
if (_name != value)
{
_name = value;
OnPropertyChanged(nameof(Name));
OnPropertyChanged(nameof(NameBrush));
}
}
}
public Brush NameBrush
{
get
{
switch (Name)
{
case "John":
return Brushes.LightGreen;
default:
break;
}
return Brushes.Transparent;
}
}
Dim txtCol As New DataGridTextColumn
Dim style As New Style(GetType(TextBlock))
Dim tri As New Trigger With {.Property = TextBlock.TextProperty, .Value = "John"}
tri.Setters.Add(New Setter With {.Property = TextBlock.BackgroundProperty, .Value = Brushes.Green})
style.Triggers.Add(tri)
xtCol.ElementStyle = style
// Example: Adding a converter to a column (C#)
Style styleReading = new Style(typeof(TextBlock));
Setter s = new Setter();
s.Property = TextBlock.ForegroundProperty;
Binding b = new Binding();
b.RelativeSource = RelativeSource.Self;
b.Path = new PropertyPath(TextBlock.TextProperty);
b.Converter = new ReadingForegroundSetter();
s.Value = b;
styleReading.Setters.Add(s);
col.ElementStyle = styleReading;
If you need to do it with a set number of columns, H.B.'s way is best. But if you don't know how many columns you are dealing with until runtime, then the below code [read: hack] will work. I am not sure if there is a better solution with an unknown number of columns. It took me two days working at it off and on to get it, so I'm sticking with it regardless.
C#
public class ValueToBrushConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
int input;
try
{
DataGridCell dgc = (DataGridCell)value;
System.Data.DataRowView rowView = (System.Data.DataRowView)dgc.DataContext;
input = (int)rowView.Row.ItemArray[dgc.Column.DisplayIndex];
}
catch (InvalidCastException e)
{
return DependencyProperty.UnsetValue;
}
switch (input)
{
case 1: return Brushes.Red;
case 2: return Brushes.White;
case 3: return Brushes.Blue;
default: return DependencyProperty.UnsetValue;
}
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotSupportedException();
}
}
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
Color color = VSColorTheme.GetThemedColor(EnvironmentColors.ToolWindowBackgroundColorKey);
return "#" + color.Name;
}
This may be of help to you. It isn't the stock WPF datagrid however.
I used DevExpress with a custom ColorFormatter behaviour. I couldn't find anything on the market that did this out of the box. This took me a few days to develop. My code attaached below, hopefully this helps someone out there.
Edit: I used POCO view models and MVVM however you could change this to not use POCO if you desire.
Viewmodel.cs
namespace ViewModel
{
[POCOViewModel]
public class Table2DViewModel
{
public ITable2DView Table2DView { get; set; }
public DataTable ItemsTable { get; set; }
public Table2DViewModel()
{
}
public Table2DViewModel(MainViewModel mainViewModel, ITable2DView table2DView) : base(mainViewModel)
{
Table2DView = table2DView;
CreateTable();
}
private void CreateTable()
{
var dt = new DataTable();
var xAxisStrings = new string[]{"X1","X2","X3"};
var yAxisStrings = new string[]{"Y1","Y2","Y3"};
//TODO determine your min, max number for your colours
var minValue = 0;
var maxValue = 100;
Table2DView.SetColorFormatter(minValue,maxValue, null);
//Add the columns
dt.Columns.Add(" ", typeof(string));
foreach (var x in xAxisStrings) dt.Columns.Add(x, typeof(double));
//Add all the values
double z = 0;
for (var y = 0; y < yAxisStrings.Length; y++)
{
var dr = dt.NewRow();
dr[" "] = yAxisStrings[y];
for (var x = 0; x < xAxisStrings.Length; x++)
{
//TODO put your actual values here!
dr[xAxisStrings[x]] = z++; //Add a random values
}
dt.Rows.Add(dr);
}
ItemsTable = dt;
}
public static Table2DViewModel Create(MainViewModel mainViewModel, ITable2DView table2DView)
{
var factory = ViewModelSource.Factory((MainViewModel mainVm, ITable2DView view) => new Table2DViewModel(mainVm, view));
return factory(mainViewModel, table2DView);
}
}
}