How to deal with empty RichTextBox selection [duplicate] - c#

I need to set the font family for the next text to be written in a RichTextBox.
I tried setting that with...
<RichTextBox x:Name="RichTextEditor" MaxWidth="1000" SpellCheck.IsEnabled="True"
FontFamily="{Binding ElementName=TextFontComboBox, Path=SelectedItem}"
FontSize="{Binding ElementName=TextSizeComboBox, Path=SelectedValue}"
Width="Auto" Height="Auto" HorizontalScrollBarVisibility="Auto"
VerticalScrollBarVisibility="Auto" />
...but it changed the whole text. I suppose that with the Selection property I can restrict the change to be applied just to the selected area. But how for the next -not yet typed- text?

In order to set the FontFamily based on the cursor position you need to define a custom control with a dependency property that helps insert a new Run section by overriding the OnTextInput method.
I included most of the code, you'll need to modify the namespaces to fit your development environment.
The code uses a ViewModel to manage the available fonts and manage if the font changed.
This code is only a prototype and does not deal with focusing issues between the two controls.
To use this code:
1- Type some text in the RichTectBox.
2- Change the font in the ComboBox.
3- Tab back to the RichTextBox.
4- Type some more text.
Here is the custom RichTextBox control:
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
namespace RichTextboxFont.Views
{
public class RichTextBoxCustom : RichTextBox
{
public static readonly DependencyProperty CurrentFontFamilyProperty =
DependencyProperty.Register("CurrentFontFamily",
typeof(FontFamily), typeof
(RichTextBoxCustom),
new FrameworkPropertyMetadata(new FontFamily("Tahoma"),
FrameworkPropertyMetadataOptions.BindsTwoWayByDefault,
new PropertyChangedCallback(OnCurrentFontChanged)));
public FontFamily CurrentFontFamily
{
get
{
return (FontFamily)GetValue(CurrentFontFamilyProperty);
}
set
{
SetValue(CurrentFontFamilyProperty, value);
}
}
private static void OnCurrentFontChanged(DependencyObject o, DependencyPropertyChangedEventArgs e)
{}
protected override void OnTextInput(TextCompositionEventArgs e)
{
ViewModels.MainViewModel mwvm = this.DataContext as ViewModels.MainViewModel;
if ((mwvm != null) && (mwvm.FontChanged))
{
TextPointer textPointer = this.CaretPosition.GetInsertionPosition(LogicalDirection.Forward);
Run run = new Run(e.Text, textPointer);
run.FontFamily = this.CurrentFontFamily;
this.CaretPosition = run.ElementEnd;
mwvm.FontChanged = false;
}
else
{
base.OnTextInput(e);
}
}
}
}
Here is the XAML:
<Window x:Class="RichTextboxFont.Views.MainView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:RichTextboxFont.Views"
xmlns:ViewModels="clr-namespace:RichTextboxFont.ViewModels"
Title="Main Window"
Height="400" Width="800">
<DockPanel>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition/>
</Grid.RowDefinitions>
<ComboBox ItemsSource="{Binding Path=Fonts}"
SelectedItem="{Binding Path=SelectedFont, Mode=TwoWay}"/>
<local:RichTextBoxCustom Grid.Row="1"
CurrentFontFamily="{Binding Path=SelectedFont, Mode=TwoWay}"
FontSize="30"/>
</Grid>
</DockPanel>
</Window>
Here is the ViewModel:
If you do not use view models, let me know and I'll add the base class code too; otherwise, google/stackoverflow can help you too.
using System.Collections.ObjectModel;
using System.Windows.Media;
namespace RichTextboxFont.ViewModels
{
public class MainViewModel : ViewModelBase
{
#region Constructor
public MainViewModel()
{
FontFamily f1 = new FontFamily("Georgia");
_fonts.Add(f1);
FontFamily f2 = new FontFamily("Tahoma");
_fonts.Add(f2);
}
private ObservableCollection<FontFamily> _fonts = new ObservableCollection<FontFamily>();
public ObservableCollection<FontFamily> Fonts
{
get
{
return _fonts;
}
set
{
_fonts = value;
OnPropertyChanged("Fonts");
}
}
private FontFamily _selectedFont = new FontFamily("Tahoma");
public FontFamily SelectedFont
{
get
{
return _selectedFont;
}
set
{
_selectedFont = value;
FontChanged = true;
OnPropertyChanged("SelectedFont");
}
}
private bool _fontChanged = false;
public bool FontChanged
{
get
{
return _fontChanged;
}
set
{
_fontChanged = value;
OnPropertyChanged("FontChanged");
}
}
#endregion
}
}
Here is the Window code-behind where I initialise the ViewModel:
using System.Windows;
namespace RichTextboxFont.Views
{
public partial class MainView : Window
{
public MainView()
{
InitializeComponent();
this.DataContext = new ViewModels.MainViewModel();
}
}
}

There's a much easier way to do this: Implement a toolbar for your RichTextBox.
Unlike WinForms, the RichTextBox in WPF doesn't come with a toolbar by default, but it's really easy to create one yourself. The RichTextBox automatically handles many EditingCommands, so it's just a matter of creating a toolbar and some buttons. Microsoft has provided sample code for this at the bottom of the RichTextBox Overview on MSDN.
Unfortunately, those editing commands don't include setting the FontFace property of the selection, though you can create a ComboBox on the toolbar that can trigger the change with an event handler in the codebehind file.
That's the approach taken in this CodePlex article by Gregor Pross: WPF RichTextEditor
The project is commented in German, but the source itself is very clearly written. The codebehind used for his font selector ComboBox looks like this:
private void Fonttype_DropDownClosed(object sender, EventArgs e)
{
string fontName = (string)Fonttype.SelectedItem;
if (fontName != null)
{
RichTextControl.Selection.ApplyPropertyValue(System.Windows.Controls.RichTextBox.FontFamilyProperty, fontName);
RichTextControl.Focus();
}
}
The main reason that people struggle with the FontFace selection is that after the font selection has been made, you must return focus to the RichTextBox. If the user must manually press tab or click into the RichTextBox, a new text selection gets created and you lose the formatting options you've chosen.
One of the answers to this StackOverflow question discusses that problem.
WPF Richtextbox FontFace/FontSize

This isn't exactly a trivial answer.
To do inline text formatting in a Rich TextBox like you want you will have to modify the Document property of the RichTextBox. Very simply, something like this will work
<RichTextBox >
<RichTextBox.Document>
<FlowDocument>
<Paragraph>
<Run>Something</Run>
<Run FontWeight="Bold">Something Else</Run>
</Paragraph>
</FlowDocument>
</RichTextBox.Document>
</RichTextBox>
I think you could create a custom Control that creates a new block element and sets the font properties you need based on the user input.
For example, If the user types something then presses bold. You would want to wrap the previous text in a run and create a new run element setting the FontWeight to bold then the subsequent text will be wrapped in the bolded run.
Again, not a trivial solution but I can't think of any other way to accomplish what you are after.

Related

Simple implementation of a textblock or textfield or richtext that allows a URL in WPF using C#

I have looked at various solutions on how to have a simple URL on a textfield, a rich text field in a WPF implementation using C#.
Tried to implement solutions on Clicking HyperLinks in a RichTextBox without holding down CTRL - WPF and Add clickable hyperlinks to a RichTextBox without new paragraph. It just looks overly complicated for what i think should be a simple task.
<RichTextBox IsReadOnly="True" IsDocumentEnabled="True">
<FlowDocument>
<Paragraph FontSize="12"> See www.google.com</Paragraph>
</FlowDocument>
</RichTextBox>
I also tried the implementation on the link
Example using Hyperlink in WPF
Here, the error I get is this.
MainWindow does not contain a definition of Hyperlink_RequestNAvigate and no accessible extension method hyperlink_RequestNavigate accepting a first argument of type MainWindow could be found, are you missing a using directive of an assembly reference.
<TextBlock>
<Hyperlink NavigateUri="http://www.google.com" RequestNavigate="Hyperlink_RequestNavigate">
Click here
</Hyperlink>
</TextBlock>
code behind
private void Hyperlink_RequestNavigate(object sender, RequestNavigateEventArgs e)
{
// for .NET Core you need to add UseShellExecute = true
// see https://learn.microsoft.com/dotnet/api/system.diagnostics.processstartinfo.useshellexecute#property-value
Process.Start(new ProcessStartInfo(e.Uri.AbsoluteUri));
e.Handled = true;
}
I am looking to have a text saying for more information click here and if the user clicks on click here, they navigate to a predefined url.
The way I've implemented hyperlinks in the past is to create a attached property, which you can add onto the Hyperlink, which will handle the RequestNavigate itself.
For example:
namespace WpfDemo.Extensions
{
public static class HyperlinkExtensions
{
public static bool GetIsExternal(DependencyObject obj)
{
return (bool)obj.GetValue(IsExternalProperty);
}
public static void SetIsExternal(DependencyObject obj, bool value)
{
obj.SetValue(IsExternalProperty, value);
}
public static readonly DependencyProperty IsExternalProperty =
DependencyProperty.RegisterAttached("IsExternal", typeof(bool), typeof(HyperlinkExtensions), new UIPropertyMetadata(false, OnIsExternalChanged));
private static void OnIsExternalChanged(object sender, DependencyPropertyChangedEventArgs args)
{
var hyperlink = sender as Hyperlink;
if ((bool)args.NewValue)
hyperlink.RequestNavigate += Hyperlink_RequestNavigate;
else
hyperlink.RequestNavigate -= Hyperlink_RequestNavigate;
}
private static void Hyperlink_RequestNavigate(object sender, System.Windows.Navigation.RequestNavigateEventArgs e)
{
ProcessStartInfo psi = new()
{
FileName = e.Uri.AbsoluteUri,
UseShellExecute = true,
};
Process.Start(psi);
e.Handled = true;
}
}
}
The code defines an attached property that when you add to a Hyperlink, will handle the logic for navigating to the links for you.
You can use the following code the following way:
<Window
x:Class="WpfDemo.MainWindow"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:helper="clr-namespace:WpfDemo.Extensions"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
<Grid>
<TextBlock>
<Hyperlink helper:HyperlinkExtensions.IsExternal="true" NavigateUri="https://google.com">
Google Link
</Hyperlink>
</TextBlock>
</Grid>
</Window>

RichTextBox Binding is broken when text is manually modified or cleared

I have a RichTextBox bound to a string.
Using C# I generate a string that writes to it.
But if I want to manually change the text by clicking into the RichTextBox and deleting it with the backspace key, or pressing Enter to make a new line, the binding becomes broken and I can no longer programmatically write to it with the string a second time.
XAML
<RichTextBox x:Name="rtbScriptView"
Margin="11,71,280,56"
Padding="10,10,10,48"
FontSize="14"
Grid.ColumnSpan="1"
VerticalScrollBarVisibility="Auto"
RenderOptions.ClearTypeHint="Enabled"
Style="{DynamicResource RichTextBoxStyle}">
<FlowDocument>
<Paragraph>
<Run Text="{Binding ScriptView_Text,
Mode=TwoWay,
UpdateSourceTrigger=PropertyChanged}" />
</Paragraph>
</FlowDocument>
</RichTextBox>
View Model
private string _ScriptView_Text;
public string ScriptView_Text
{
get { return _ScriptView_Text; }
set
{
if (_ScriptView_Text == value)
{
return;
}
_ScriptView_Text = value;
OnPropertyChanged("ScriptView_Text");
}
}
C#
ViewModel vm = new ViewModel();
DataContext = vm;
// Display a string in the RichTextBox
vm.ScriptView_Text = "This is a test."; // <-- This won't work if text is manually modified
When you edit the RichTextBox, you alter the elements inside of the FlowDocument element. The element you have a binding on, is probably removed at some point during this editing.
Have a look at RichtTextBox.Document.Groups to see what's happening when you edit the RichTextBox.
The default RichTextBox does not really support MVVM/Binding very well. You'd want to have a binding on the Document property, but this is not supported for the default RichTextBox.
You could have a look here.
Or extend it yourself, something like this?:
BindableRichTextBox class
public class BindableRichTextBox : RichTextBox
{
public static readonly DependencyProperty DocumentProperty = DependencyProperty.Register(nameof(Document), typeof(FlowDocument), typeof(BindableRichTextBox), new FrameworkPropertyMetadata(null, OnDocumentChanged));
public new FlowDocument Document
{
get => (FlowDocument)GetValue(DocumentProperty);
set => SetValue(DocumentProperty, value);
}
public static void OnDocumentChanged(DependencyObject obj, DependencyPropertyChangedEventArgs args)
{
var rtb = (RichTextBox)obj;
rtb.Document = args.NewValue != null ? (FlowDocument)args.NewValue : new FlowDocument();
}
}
XAML
<controls:BindableRichTextBox Document="{Binding YourFlowDocumentObject, Mode=OneWay}"/>
Then you can get the string from the FlowDocument.
Why you have to write this line. Please remove line after check.
if (_ScriptView_Text == value)
{
return;
}

FlowDocument and XamlReader x:Class

In my MainWindow I have a FlowDocumentScrollViewer binding its property Document to a FlowDocument in my MainViewModel.
This document is loaded from an external xaml file store on a remote computer. Currently I'm able to load this document properly via XamlReader.Load(xamlfile) and display it in the FlowDocumentScrollViewer. So far so good.
The problem occurs when I try to add hyperlink in this document. Because to handle the RequestNavigate event I need a x:Class. For the time being this Class need to be my MainWindow because the event is handle in the code-behind. Obviously when I add x:Class="Ugrader.MainWindow" in my external document I get a lovely 'System.Windows.Markup.XamlParseException' at the moment of parsing.
So is there a way to solve this ?
Here is piece of my code
MainWindow.xaml
<Window x:Class="Ugrader.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Geco3-Upgrading version"
WindowStyle="none" ResizeMode="NoResize" ShowInTaskbar="False" WindowStartupLocation="CenterScreen"
Height="400" Width="700"
DataContext="{Binding Main,Source={StaticResource Locator}}">
<FlowDocumentScrollViewer Grid.Column="1" Background="{x:Null}" VerticalScrollBarVisibility="Hidden"
Document="{Binding WhatsNewDoc}"/>
</Window>
MainViewModel.cs
namespace Ugrader.ViewModel
{
public class MainViewModel : ViewModelBase
{
#region Constructor
public MainViewModel()
{
try
{
FileStream xamlFile = new FileStream(updateLocation + "whatsnew.xaml", FileMode.Open, FileAccess.Read);
FlowDocument current = System.Windows.Markup.XamlReader.Load(xamlFile) as FlowDocument;
WhatsNewDoc = current;
}
catch (Exception)
{
}
}
#endregion
#region Properties
private FlowDocument _watsNewDoc = new FlowDocument();
public FlowDocument WhatsNewDoc
{
get
{
return _watsNewDoc;
}
set
{
if(_watsNewDoc != value)
{
_watsNewDoc = value;
RaisePropertyChanged("WhatsNewDoc");
}
}
}
#endregion
}
}
The external FlowDocument
<FlowDocument x:Class="Ugrader.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
ColumnWidth="400" FontSize="12" FontFamily="Century Gothic" Foreground="LightGray">
<Paragraph>
<Italic>
For additionnal information, please watch this
<Hyperlink TextDecorations="{x:Null}" RequestNavigate="Hyperlink_Clicked" NavigateUri="path_to_the_file" >video</Hyperlink>
</Italic>
</Paragraph>
</FlowDocument>
By the way, is there a way to handle this parse exception (in case of bad external file), because even in this try/catch block, this stop my program.
Thanks you in advance,
Bastien.
I find a way to deal with my problem, it's not really beautiful, do not respect the spirit of mvvm, but well, this is working.
So, as it's not possible to add x:Class at runtime (I guess), I came to the idea of handling the RequestNavigate event of each Hyperlinkat runtime. So the solution is pretty simple (and dirty).
In code-behind (yeah I know, it's ugly), on the MainWindow loaded event, I find all hyperlinks in my document, and handle each RequestNavigate events. As simple (and dirty) as this.
Here is some code :
private void Window_Loaded(object sender, RoutedEventArgs e)
{
var hyperlinks = GetVisuals(this).OfType<Hyperlink>();
foreach (var link in hyperlinks)
link.RequestNavigate += link_RequestNavigate;
}
public static IEnumerable<DependencyObject> GetVisuals(DependencyObject root)
{
foreach (var child in LogicalTreeHelper.GetChildren(root).OfType<DependencyObject>())
{
yield return child;
foreach (var descendants in GetVisuals(child))
yield return descendants;
}
}
If someone has a better solution, I take it.

Resize body of a WebBrowser as UserControl

I am developing a screen, and this screen I have a grid. Within this grid, I have a UserControl WebBrowser. I'm using this component to display XML formatted and syntax is highlighted (with color). The text to be displayed is done via Binding, so that the component is a UserControl, as was done for the same modifications accepted Binding (since the original does not accept content via Binding). But I'm experiencing the following problem: when the user resizes the screen of the program at a certain point, the body of the WebBrowser beyond the boundaries of the grid, making the screen is strange at the bottom of the Grid.
I tested with other components, and this problem does not occur.
Behold my UserControl:
<UserControl x: Class = "Geraes.Library.Core.GUI.WPF.Controls.XmlBrowserControl"
xmlns = "http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns: x = "http://schemas.microsoft.com/winfx/2006/xaml"
x: Name = "thisControl">
<Grid Margin="0,0,0,0" VerticalAlignment="Stretch" HorizontalAlignment="Stretch">
<WebBrowser Name="WebBrowser" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" />
</ Grid>
</ UserControl>
And here, how I use it:
<ct:XmlBrowserControl XmlDoc="{Binding ContentString}" Grid.Row="1" />
Again, I can't understand why this is happening, since other components works as well inside this grid.
Another thing: we're using WebBrowser because until this moment, it's the best component to show a XML formatted and with syntax-colour. But if you know another one than its better and easy to use, i'm accepting suggestions.
Any help is welcome.
Best regards,
Gustavo.
I was having a similar problem using the webbrowser control, in the end I switched to using awesomium and have found it much nicer to use.
I wanted to size the content of the webbrowser (or webcontrol) to fit content without scroll bars so I could use the scrollbars of the containing element (in my case a grid). I also started with a custom control but then switched to adding the the binding source as an attached property instead and setting the sizes and visibility once the content had loaded. I my case I was using you localing stored html string, but you could use a uri instead
using System;
using System.Windows;
using Awesomium.Windows.Controls;
using Awesomium.Core;
namespace utilities
{
public class WebBrowserHelper {
public static readonly DependencyProperty BodyProperty =
DependencyProperty.RegisterAttached("Body", typeof (string), typeof(WebBrowserHelper), new PropertyMetadata(OnBodyChanged));
public static string GetBody(DependencyObject dependencyObject) {
return (string) dependencyObject.GetValue(BodyProperty);
}
public static void SetBody(DependencyObject dependencyObject, string body) {
dependencyObject.SetValue(BodyProperty, body);
}
private static void ScrollDataReceivedDelegate(object sender, ScrollDataEventArgs e)
{
var webControl = (Awesomium.Windows.Controls.WebControl) sender;
webControl.Height = e.ScrollData.ContentHeight;
webControl.Width = e.ScrollData.ContentWidth;
webControl.Visibility = Visibility.Visible;
}
private static void OnBodyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) {
var webControl = (Awesomium.Windows.Controls.WebControl) d;
webControl.LoadHTML((string)e.NewValue);
webControl.ScrollDataReceived += new ScrollDataReceivedEventHandler(ScrollDataReceivedDelegate);
webControl.LoadCompleted += delegate {
webControl.RequestScrollData();
};
}
}
}
And the namespaces:
xmlns:utilities="clr-namespace:utilities;assembly=utilities"
xmlns:awesome="clr-namespace:Awesomium.Windows.Controls;assembly=Awesomium.Windows.Controls"
And the xaml:
<awesome:WebControl
HorizontalAlignment="Left"
Width="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Grid}}, Path=ActualWidth}"
Height="1"
utilities:WebBrowserHelper.Body="{Binding html}"
Visibility="Collapsed" />

Metadata overriding ignored?

I have made a very simple test project:
MainWindow.xaml:
<Window x:Class="Test.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:Test"
Title="MainWindow" Height="350" Width="525" VerticalAlignment="Center" HorizontalAlignment="Center">
<StackPanel x:Name="mainPanel" />
</Window>
MainWindow.xaml.cs:
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
namespace Test
{
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
MyTextBox myTextBox = new MyTextBox("some text here");
mainPanel.Children.Add(myTextBox);
}
}
}
MyTextBox.cs:
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
namespace Test
{
class MyTextBox : TextBox
{
static MyTextBox()
{
MyTextBox.BackgroundProperty.OverrideMetadata(typeof(MyTextBox), new FrameworkPropertyMetadata(Brushes.Red));
}
public MyTextBox(string Content)
{
Text = Content;
}
}
}
this, in order to test the metaData Overriding function.
now the trouble is: this does not work as I expected it to...
indeed, the MyTextBox's background is white, and not Red.
I investigated and tried this as constructor for my custom class:
public MyTextBox(string Content)
{
Text = Content;
Background = Brushes.Blue;
ClearValue(BackgroundProperty);
}
now here is what I found out when I debugged:
in the main class:
MyTextBox myTextBox = new MyTextBox("some text here");
we go into the custom class's static constructor, then in the instance's constructor:
Text = Content; >> Background = Red
Background = Brushes.Blue; >> Background = Blue
ClearValue(BackgroundProperty); >> Background = Red again (as expected)
we go back to the main class:
mainPanel.Children.Add(myTextBox);
... and right after this line of code, myTextBox.Background is White.
Question: Why?
why is this set to white when I add it to the mainPanel??? I cannot find any logical explanation to this...
furthermore, if I add some more code where I do something like: myTextBox.Background = Brushes.Blue; and then myTextBox.ClearValue(MyTextBox.BackgroundProperty);, it becomes Blue then White again, instead of Red.
I don't understand.
The Background is being set by the default Style of the TextBox. Based on the Dependency Property Value Precedence Red is at #11, while the default Style is at #9. The Blue setting would be at #3, so that should override the Background fine.
You would either have to set the background explicitly (like you do with the Blue brush), or create your own custom default style that doesn't set the Background. Your default style can be based on the TextBox version.
You can set Background in a style applied to your MyTextBox:
<Application.Resources>
<Style TargetType="local:MyTextBox">
<Setter Property="Background" Value="Red" />
</Style>
</Application.Resources>
As CodeNaked mentioned your default metadata value is being overriden by default style for textbox. You can see it if you will change your code:
MyTextBox.cs:
Control.BackgroundProperty.OverrideMetadata(typeof(MyTextBox), new FrameworkPropertyMetadata(Brushes.Red,
FrameworkPropertyMetadataOptions.Inherits, PropertyChangedCallback));
private static void PropertyChangedCallback(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs dependencyPropertyChangedEventArgs)
{
// set breakpoint here
}
When breakpoint will be breaked you will be able to see that OldValue was Red, NewValue is White and from stack-trace you can see that it happens because of default style being applied.

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