Custom textblock that transforms its content to different color

Question

I will write a custom textblock that splits its text content. It will make texts diffent colors depending on conditions and the texts will be separated with commas. Commas will remain black. I don't know how to start. Could you please provide help to start?

Thanks in advance

Grampositive

Answer 1

Below user control uses an items control to show each token with some random color.

Usage:

 <local:ColorTextBlock Text="abcd,abcde, abc, abcdef, abc, abcde, "/> 

XAML:

<UserControl x:Class="WpfApplication1.ColorTextBlock"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:WpfApplication1"
             mc:Ignorable="d">

    <UserControl.Resources>
        <local:TextColorConverter x:Key="TextColorConverter" />
    </UserControl.Resources>

    <ItemsControl Name="_itemsControl">
        <ItemsControl.ItemTemplate>
            <DataTemplate>
                <TextBlock Text="{Binding .}" Foreground="{Binding ., Converter={StaticResource TextColorConverter}}" />
            </DataTemplate>
        </ItemsControl.ItemTemplate>
        <ItemsControl.ItemsPanel>
            <ItemsPanelTemplate>
                <StackPanel Orientation="Horizontal" />
            </ItemsPanelTemplate>
        </ItemsControl.ItemsPanel>
    </ItemsControl>
</UserControl>

Code behind:

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Media;

namespace WpfApplication1
{
    public partial class ColorTextBlock : UserControl
    {
        public ColorTextBlock()
        {
            InitializeComponent();
        }

        public string Text
        {
            get { return (string)GetValue(TextProperty); }
            set { SetValue(TextProperty, value); }
        }

        public static readonly DependencyProperty TextProperty = 
            DependencyProperty.Register("Text", typeof(string), typeof(ColorTextBlock), new UIPropertyMetadata(""));

        protected override void OnPropertyChanged(DependencyPropertyChangedEventArgs e)
        {
            base.OnPropertyChanged(e);

            if (e.Property.Name == "Text")
            {
                // Below code does not handle text that includes stars. Null check probably needed. 
                _itemsControl.ItemsSource = Text.Replace(",", "*,*").Split('*');
            }
        }
    }

    public class TextColorConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            string text = value as string;
            if (text == ",") return Brushes.Black;

            return new SolidColorBrush() { Color = Color.FromArgb(255, (byte)_random.Next(255), (byte)_random.Next(255), (byte)_random.Next(255)) };
        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }

        private static Random _random = new Random();
    }
}

Estrade

Thanks I will try this solution. Hope it will help – Grampositive