Develop Reference

Is it possible to bind the foreground color of any textcontrol

So I've been trying to figure this out for 3 days and I just can't seem to find a solution.
This is what I am trying to achieve.
I have a simple WPF project with a RichTextBox in it.
What my application is doing is that it acts like a CMD.
What I want to do now is that I want to change the message it saved when I press enter, I want the previous message to change color.
Here is a GIF showing what it looks like
https://i.imgur.com/srszUKG.gifv
I tried binding the Foreground of the TextBox inside the DataTemplate but that just made it to where the text wouldnt even show up.
<DataTemplate>
<TextBlock Text="{Binding Path=.}" Foreground="White" Name="SavedBlocks" FontFamily="Consolas"/>
</DataTemplate>
So what are my options here, I essentially want to change the color of the text depending on how long the message is.
XAML
<Window x:Class="WpfApp1Eh.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WpfApp1Eh"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Grid>
<ScrollViewer Name="Scroller" Margin="0" Background="Black">
<StackPanel>
<ItemsControl ItemsSource="{Binding ConsoleOutput, Mode=OneWay}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=.}" Foreground="White" Name="SavedBlocks" FontFamily="Consolas"/>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
<TextBox Text="{Binding ConsoleInput, Mode=TwoWay}" Background="Black" Foreground="White" FontFamily="Consolas" Name="InputBlock" BorderBrush="{x:Null}" SelectionBrush="{x:Null}" />
</StackPanel>
</ScrollViewer>
</Grid>
</Window>
main.cs
public partial class MainWindow : Window
{
ConsoleContent dc = new ConsoleContent();
public MainWindow()
{
InitializeComponent();
Loaded += MainWindow_Loaded1;
DataContext = dc;
}
private void MainWindow_Loaded1(object sender, RoutedEventArgs e)
{
InputBlock.KeyDown += InputBlock_KeyDown;
InputBlock.Focus();
}
void InputBlock_KeyDown(object sender, KeyEventArgs e)
{
if (e.Key == Key.Enter)
{
dc.ConsoleInput = InputBlock.Text;
dc.RunCommand();
InputBlock.Focus();
Scroller.ScrollToBottom();
}
}
}
ConsoleContent.cs
public class ConsoleContent : INotifyPropertyChanged
{
string consoleInput = string.Empty;
ObservableCollection<string> consoleOutput = new ObservableCollection<string>() { "Console Emulation Sample..." };
public string ConsoleInput
{
get
{
return consoleInput;
}
set
{
consoleInput = value;
OnPropertyChanged("ConsoleInput");
}
}
public ObservableCollection<string> ConsoleOutput
{
get
{
return consoleOutput;
}
set
{
consoleOutput = value;
OnPropertyChanged("ConsoleOutput");
}
}
public void RunCommand()
{
ConsoleOutput.Add(ConsoleInput);
//myBrush = Brushes.Orange;
// do your stuff here.
ConsoleInput = String.Empty;
}
private System.Windows.Media.Brush _foregroundColor = System.Windows.Media.Brushes.DarkSeaGreen;
public System.Windows.Media.Brush ForegroundColor
{
get { return _foregroundColor; }
set
{
_foregroundColor = value;
OnPropertyChanged("ForegroundColor");
}
}
public event PropertyChangedEventHandler PropertyChanged;
void OnPropertyChanged(string propertyName)
{
if (null != PropertyChanged)
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}

Change the type of consoleOutput from ObservableCollection<string> to ObservableCollection<YourType> where YourType is a class that represents a line of input with a text string and a Foreground Brush:
public class YourType : INotifyPropertyChanged
{
private string _text;
public string Text
{
get { return _text; }
set { _text = value; OnPropertyChanged("Text"); }
}
private Brush _foreground;
public Brush Foreground
{
get { return _foreground; }
set { _foreground = value; OnPropertyChanged("Foreground"); }
}
public event PropertyChangedEventHandler PropertyChanged;
void OnPropertyChanged(string propertyName)
{
if (null != PropertyChanged)
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
Bind to the properties of this class in your XAML:
<ScrollViewer Name="Scroller" Margin="0" Background="Black">
<StackPanel>
<ItemsControl ItemsSource="{Binding ConsoleOutput, Mode=OneWay}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Text}"
Foreground="{Binding Foreground}"
Name="SavedBlocks" FontFamily="Consolas"/>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
<TextBox Text="{Binding ConsoleInput, Mode=TwoWay}" Background="Black" Foreground="White" FontFamily="Consolas" Name="InputBlock" BorderBrush="{x:Null}" SelectionBrush="{x:Null}" />
</StackPanel>
</ScrollViewer>
You can then set the Foreground property of each individual item in the source collection:
public void RunCommand()
{
ConsoleOutput.Add(new YourType { Text = ConsoleInput, Foreground = Brushes.Orange } );
ConsoleInput = String.Empty;
}

Call Command from another class (WPF, Mvvm)

I made a Listbox with Checkboxes in it. The Listbox is bound to a List of my Checkbox class. Now i want to call a command from my DataContext instead of my Checkbox class when i check/uncheck the Checkbox
<ListBox Grid.Column="1" ItemsSource="{Binding Databases}">
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal"></StackPanel>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
<ListBox.ItemTemplate>
<DataTemplate>
<CheckBox Content="{Binding Name}" IsChecked="{Binding IsChecked, Mode=TwoWay}" Margin="5 5 0 0" />
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
CheckBox class:
public class CheckBoxDatabase
{
private string name;
protected bool isChecked;
public ObservableCollection<CheckBoxDatabase> Owner;
public bool IsChecked
{
get { return isChecked; }
set
{
setzeChecked(value);
NotifyPropertyChanged();
}
}
public virtual void setzeChecked(bool value)
{
isChecked = value;
}
public string Name
{
get { return name; }
set
{
name = value;
NotifyPropertyChanged();
}
}
#region NotifyPropertyChanged
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged([CallerMemberName] string propertyName = "")
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
#endregion
}
My main problem is if i add a command, it tells me that it is not found in the class (of course because i want it to call it in my datacontext class where i have a relaycommand. (also got another relay command independent of all this which is working where i did exactly the same)

If you want to bind to an ICommand property of the class where the Databases source collection is defined, you could use a RelativeSource:
<CheckBox Content="{Binding Name}" Command="{Binding DataContext.YourCommandProperty, RelativeSource={RelativeSource AncestorType=ListBox}}" Margin="5 5 0 0" />
Replace YourCommandProperty with the actual name of your property.

How to update TextBlock text inside of ListBox item

So I have a simple UDP chat app from a WinForm project, which I wanted to look a little bit better, so I am re-making it in WPF. As I realized I can easily put 2 or more TextBlocks inside of a ListItem, I wanted to display the last message of each chat, like so:
But I have no Idea on how to edit those TextBlocks :( I literary just started with WPF, so I bet I just made a duplicate, but because of that, I don't even know how to search for this issue.
Here is the custom ListBox:
<ListBox x:Name="myList" HorizontalAlignment="Left" Width="264" ScrollViewer.VerticalScrollBarVisibility="Hidden" ScrollViewer.HorizontalScrollBarVisibility="Disabled" BorderThickness="0,1,1,0" MouseLeftButtonUp="myList_MouseLeftButtonUp" Margin="0,25,0,0">
<ListBox.ItemTemplate>
<DataTemplate>
<Border BorderBrush="LightGray" BorderThickness="0,0,0,1" Width="250">
<DockPanel Margin="0,7">
<Ellipse Name="ellipse" Margin="5" DockPanel.Dock="Left" Style="{DynamicResource elstyle}">
</Ellipse>
<TextBlock Text="{Binding Name}" DockPanel.Dock="Top" Margin="0,0,0,7" FontWeight="Bold" MaxWidth="250"></TextBlock>
<TextBlock Text="{Binding ID}" DockPanel.Dock="Top" Visibility="Hidden" FontSize="1.333"></TextBlock>
<TextBlock x:Name="last_message" Text="{Binding LastMessage}" DockPanel.Dock="Bottom" MaxWidth="250"></TextBlock>
</DockPanel>
</Border>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>

This is simplified model to show the principal but if you would create view model class that implement INotifyPropertyChanged interface to hold your item data
public class MyItem : INotifyPropertyChanged
{
private string _name;
private string _id;
private string _lastMessage;
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string propertyName)
{
var handler = this.PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
public string Name
{
get { return _name; }
set
{
_name = value;
OnPropertyChanged("Name");
}
}
public string ID
{
get { return _id; }
set
{
_id = value;
OnPropertyChanged("ID");
}
}
public string LastMessage
{
get { return _lastMessage; }
set
{
_lastMessage = value;
OnPropertyChanged("LastMessage");
}
}
}
and then in your window
public partial class MainWindow : Window
{
private readonly ObservableCollection<MyItem> _myItems = new ObservableCollection<MyItem>();
public MainWindow()
{
InitializeComponent();
myList.ItemsSource = _myItems;
_myItems.Add(new MyItem { Name = "name", ID = "id", LastMessage = "last message" });
_myItems[0].LastMessage = "new message";
}
}
and then you don't operate on myList control anymore but on _myItems list and its items. If you add/remove item in the collection it will add/remove item in the UI, if you change property of an item it will update bound property in the UI

Changing ObservableCollection at runtime for binding

I am generating Grid for every item from my ObservableCollection. Now I want to be able to change the source collection at runtime and I am not sure what needs to be done.
Here is my XAML:
<Window.Resources>
<c:GraphicsList x:Key="GraphicsData" />
</Window.Resources>
...
...
<ItemsControl x:Name="icGraphics" ItemsSource="{Binding Source={StaticResource GraphicsData}}" >
<ItemsControl.ItemTemplate>
<DataTemplate>
<Grid Tag="{Binding id}" Margin="15,0,15,15">
<Label Grid.Row="0" Content="{Binding name}"/>
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
And C#:
myCollection1 = this.FindResource("GraphicsData") as GraphicsList;
myCollection1:
public class GraphicsList : ObservableCollection<Graphics>
{
public GraphicsList()
{
}
}
Graphics class:
class Graphics: INotifyPropertyChanged
{
// some properties not important
}
Its a simplyfied version of my code, but it works, I basically a want to change the source collection myCollection1 to myCollection2 (which is same class just different list). How do I do this?

You can Add or Remove items from collection as below
var dresource = this.Resources["GraphicsData"] as GraphicsList;
dresource.Add(new Graphics() { Name = "New Entry" });
But with StaticResource you can't assign new Collection to one in ResourceDictionary.
Ideally you should be using ViewModel and bind Collection if you want to assign completely new collection.
Your mainwindow class or viewmodel should implement INotifyPropertyChanged interface
Sample code
public partial class MainWindow : Window, INotifyPropertyChanged
{
private GraphicsList _graphicsData;
public MainWindow()
{
InitializeComponent();
DataContext = this;
this.Loaded += MainWindow_Loaded;
}
public GraphicsList GraphicsData
{
get { return _graphicsData; }
set
{
if (Equals(value, _graphicsData)) return;
_graphicsData = value;
OnPropertyChanged("GraphicsData");
}
}
void MainWindow_Loaded(object sender, RoutedEventArgs e)
{
//var resource = this.Resources["GraphicsData"] as GraphicsList;
var resource = new GraphicsList();
resource.Add(new Graphics(){Name = "Some new Collection of data"});
this.GraphicsData = resource;
}
public event PropertyChangedEventHandler PropertyChanged;
[NotifyPropertyChangedInvocator]
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
}
And Your Xaml
<Grid>
<ListBox ItemsSource="{Binding GraphicsData}">
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Name}"></TextBlock>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
I hope this will help

ListViewItem IsSelected Binding - Works for WPF, but not for WinRT

I'm trying to bind the IsSelected property of a ListViewItem to a property in a ViewModel. It works fine in WPF, but in Windows RT the IsSelected property is never getting set.
public class Item : INotifyPropertyChanged
{
private readonly string name;
private bool isSelected;
public event PropertyChangedEventHandler PropertyChanged;
public bool IsSelected
{
get { return isSelected; }
set { isSelected = value; RaisePropertyChanged("IsSelected"); }
}
public string Name { get { return name; } }
public Item(string name)
{
this.name = name;
}
protected void RaisePropertyChanged(string propertyName)
{
var handler = PropertyChanged;
if (handler != null)
handler.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
public class ViewModel
{
private readonly ObservableCollection<Item> items = new ObservableCollection<Item>(Enumerable.Range(0, 10).Select(p => new Item(p.ToString())));
public ObservableCollection<Item> Items { get { return items; } }
}
public sealed partial class MainPage : Page
{
public MainPage()
{
this.InitializeComponent();
DataContext = new ViewModel();
}
}
xaml:
<StackPanel Orientation="Horizontal">
<ListView ItemsSource="{Binding Path=Items}" SelectionMode="Multiple">
<ListView.ItemContainerStyle>
<Style TargetType="ListViewItem">
<Setter Property="IsSelected" Value="{Binding Path=IsSelected, Mode=TwoWay}"/>
</Style>
</ListView.ItemContainerStyle>
</ListView>
<ListView.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=Name}"/>
</DataTemplate>
</ListView.ItemTemplate>
</StackPanel>
I'm able to click on the items on the screen, but the IsSelected property isn't propagating to the ViewModel. Any ideas why?

A good and easy way to do this is to subclass ListView
public class MyListView : ListView
{
protected override void PrepareContainerForItemOverride(Windows.UI.Xaml.DependencyObject element, object item)
{
base.PrepareContainerForItemOverride(element, item);
// ...
ListViewItem listItem = element as ListViewItem;
Binding binding = new Binding();
binding.Mode = BindingMode.TwoWay;
binding.Source = item;
binding.Path = new PropertyPath("Selected");
listItem.SetBinding(ListViewItem.IsSelectedProperty, binding);
}
}
Alternatively, it seems you can also do it with WinRT XAML Toolkit.
<ListView
x:Name="lv"
Grid.Row="1"
Grid.Column="1"
SelectionMode="Multiple"
HorizontalAlignment="Left"
Width="500">
<ListView.ItemTemplate>
<DataTemplate>
<TextBlock
Extensions:ListViewItemExtensions.IsSelected="{Binding IsSelected}"
Extensions:ListViewItemExtensions.IsEnabled="{Binding IsEnabled}"
Text="{Binding Text}"
Margin="15,5"
FontSize="36" />
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
Personally, I used the first approach because it's more flexible and I needed to bind a few Automation Properties.
Credits to ForInfo and ehuna:
http://social.msdn.microsoft.com/Forums/windowsapps/en-US/9a0adf35-fdad-4419-9a34-a9dac052a2e3/listviewitemisselected-data-binding-in-style-setter-is-not-working

WinRT doesn't support bindings in setters at all as of Windows 8.0. Bing for workarounds.