How to change color of foreground

Question

help me please. I have DataGrid with ComboBoxColumn and I have to change foreground text.

For example: - If ComboBoxColumn have value "IT" foreground must be "Red" - If ComboBoxColumn have value "R&D" foreground must be "Yellow" - If ComboBoxColumn have value "Finance" foreground must be "Black"

<Page
    x:Class="DataGridComboBoxColumnColor.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:MSControls="using:Microsoft.Toolkit.Uwp.UI.Controls"
    xmlns:local="using:DataGridComboBoxColumnColor"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">

    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="0.3*"></ColumnDefinition>
            <ColumnDefinition Width="0.7*"></ColumnDefinition>
            <ColumnDefinition Width="0.3*"></ColumnDefinition>
        </Grid.ColumnDefinitions>

        <MSControls:DataGrid  Grid.Column="1"
                  ItemsSource="{x:Bind Persons}"
                  AutoGenerateColumns="False" 
                  ScrollViewer.HorizontalScrollMode="Enabled"
                  RowHeight="60">

            <MSControls:DataGrid.Columns>
                <MSControls:DataGridTextColumn Header="First 
                                               Name" Width="*"
                                               Binding="{Binding FirstName}"/>

                <MSControls:DataGridTextColumn Header="Last 
                                               Name" Width="*"
                                               Binding="{Binding LastName}"/>

                <MSControls:DataGridTextColumn Header="Position" 
                                               Width="*" 
                                               Binding="{Binding Position}"/>

                <MSControls:DataGridComboBoxColumn Header="Department"
                                                   Width="*"
                                                   Binding="{Binding DepartmentId}"                                                  
                                                   ItemsSource="{x:Bind Departments}"
                                                   DisplayMemberPath="DepartmentName"/>
            </MSControls:DataGrid.Columns>
        </MSControls:DataGrid>
    </Grid>
</Page>

Code behind

namespace DataGridComboBoxColumnColor
{
    public class Department
    {
        public int DepartmentId {
            get;
            set;
        }
        public string DepartmentName {
            get;
            set;
        }
    }

    public class Person
    {
        public int PersonId {
            get;
            set;
        }
        public int DepartmentId {
            get;
            set;
        }
        public string FirstName {
            get;
            set;
        }
        public string LastName {
            get;
            set;
        }
        public string Position {
            get;
            set;
        }
    }

    public sealed partial class MainPage : Page
    {
        public List<Department> Departments {
            get;
            set;
        }
        public List<Person> Persons {
            get;
            set;
        }
        public MainPage()
        {
            this.InitializeComponent();
            Departments = new List<Department>
            {
                new Department {
                    DepartmentId = 1, DepartmentName = "R&D"
                }
                ,
                new Department {
                    DepartmentId = 2, DepartmentName = "Finance"
                }
                ,
                new Department {
                    DepartmentId = 3, DepartmentName = "IT"
                }
            };
            Persons = new List<Person>
            {
                new Person
                {
                    PersonId = 1, DepartmentId = 3, FirstName = "Ronald", LastName = "Rumple",
                    Position = "Network Administrator"
                }
                ,
                new Person
                {
                    PersonId = 2, DepartmentId = 1, FirstName = "Brett", LastName = "Banner",
                    Position = "Software Developer"
                }
                ,
                new Person
                {
                    PersonId = 3, DepartmentId = 2, FirstName = "Alice", LastName = "Anderson",
                    Position = "Accountant"
                }
            };
        }
    }

}

Answer 1

How to change color of foreground

For your requirement, the better way is use IValueConverter to retune the matched foreground. Unfortunately, the foreground property of DataGridTextColumn is not DependencyProperty , so we could not use converter directly. We could use DataGridTemplateColumn to make custom cell and add a TextBlock in the CellTemplate then binding the foreground with the source like the following.

Converter

public class ColorValueConverter : IValueConverter
 {
     //IT" foreground must be "Red" - If ComboBoxColumn have value "R&D" foreground must be "Yellow"

     public object Convert(object value, Type targetType, object parameter, string language)
     {
         var solorbrush = new SolidColorBrush();
         switch (value.ToString())
         {
             case "IT":
                 solorbrush.Color = Colors.Red;
                 break;
             case "R&D":
                 solorbrush.Color = Colors.Yellow;
                 break;
             case "Finance":
                 solorbrush.Color = Colors.Black;
                 break;

             default:
                 solorbrush.Color = Colors.LightBlue;
                 break;

         }
         return solorbrush;
     }


  public object ConvertBack(object value, Type targetType, object parameter, string language)
     {
         throw new NotImplementedException();
     }
 }

Usage

<Page.Resources>    
    <local:ColorValueConverter x:Key="ColorCoverter"/>
</Page.Resources>


<controls:DataGridTemplateColumn Header="ID">
    <controls:DataGridTemplateColumn.CellTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding Id}" Foreground="{Binding Id, Converter={StaticResource ColorCoverter}}"/>
        </DataTemplate>
    </controls:DataGridTemplateColumn.CellTemplate>

</controls:DataGridTemplateColumn>