A read-only CheckBox in C# WPF - c#

I am having a tricky problem, I want some slightly unusual behaviour from a checkbox and can't seem to figure it out. Any suggestions would be most welcome. The behaviour I want is:
The CheckBox is enabled and ready for the user to click, IsChecked represents a bound boolean value stored in a data structure
The user clicks the CheckBox causing the click event to fire but the bound value in the data structure is NOT updated and the visual representation of the CheckBox is NOT updated but it is disabled to stop further clicking
The click event triggers a message to be sent to a remote device which takes some time to respond
The remote device responds causing the data structure to be updated with the new value, the binding then updates the isChecked status and the CheckBox gets reenabled for further clicking
The problem I have is that although a OneWay data binding works at not updating the data structure when the CheckBox is clicked, the visual representation does change (which I think is odd, shouldn't IsChecked now act like a pointer to the value in the data structure).
I can reverse the change in the Click() event and do the disable there as well but this is pretty messy. I can also have the set property of the data structure value to set an isEnabled value which is also bound to reenable the CheckBox but that seems messy too.
Is there a clean way to do this? Perhaps with a derived CheckBox class? How can I stop the visual representation getting updated?
Thanks
Ed

What about data binding to the IsHitTestVisible property?
For example, assuming an MVVM approach:
Add a IsReadOnly property to your view model, initially set as true to allow click.
Binding this property to CheckBox.IsHitTestVisible.
After the first click, update your view model to set this value to false, preventing any further clicks.
I don't have this exact requirement, I just needed an always read only checkbox, and it seems to solve the problem nicely. Also note Goran's comment below about the Focusable property.

This answer is not your question, but it answers the question from the title.
Checkbox in WPF does not have the IsReadOnly property.
But, similar behavior is achieved using properties
IsHitTestVisible="False" and Focusable="False"
<CheckBox IsHitTestVisible="False"
Focusable="False"/>

I don't think that creating a whole control for this is necessary.
The issue that you're running into comes from the fact that the place where you see 'the check' isn't really the checkbox, it's a bullet. If we look at the ControlTemplate for a CheckBox we can see how that happens (Though I like the Blend template better). As a part of that, even though your binding on the IsChecked property is set to OneWay it is still being updated in the UI, even if it is not setting the binding value.
As such, a really simple way to fix this, is to just modify the ControlTemplate for the checkbox in question.
If we use Blend to grab the control template we can see the Bullet inside the ControlTemplate that represents the actual checkbox area.
<BulletDecorator SnapsToDevicePixels="true"
Background="Transparent">
<BulletDecorator.Bullet>
<Microsoft_Windows_Themes:BulletChrome Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
IsChecked="{TemplateBinding IsChecked}"
RenderMouseOver="{TemplateBinding IsMouseOver}"
RenderPressed="{TemplateBinding IsPressed}" />
</BulletDecorator.Bullet>
<ContentPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
Margin="{TemplateBinding Padding}"
VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
RecognizesAccessKey="True" />
</BulletDecorator>
In here, the IsChecked and RenderPressed are what are actually making the 'Check' appear, so to fix it, we can remove the binding from the IsChecked property on the ComboBox and use it to replace the TemplateBinding on the IsChecked property of the Bullet.
Here's a small sample demonstrating the desired effect, do note that to maintain the Vista CheckBox look the PresentationFramework.Aero dll needs to be added to the project.
<Window x:Class="Sample.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:Microsoft_Windows_Themes="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Aero"
Title="Window1"
Height="300"
Width="300">
<Window.Resources>
<SolidColorBrush x:Key="CheckBoxFillNormal"
Color="#F4F4F4" />
<SolidColorBrush x:Key="CheckBoxStroke"
Color="#8E8F8F" />
<Style x:Key="EmptyCheckBoxFocusVisual">
<Setter Property="Control.Template">
<Setter.Value>
<ControlTemplate>
<Rectangle SnapsToDevicePixels="true"
Margin="1"
Stroke="Black"
StrokeDashArray="1 2"
StrokeThickness="1" />
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="CheckRadioFocusVisual">
<Setter Property="Control.Template">
<Setter.Value>
<ControlTemplate>
<Rectangle SnapsToDevicePixels="true"
Margin="14,0,0,0"
Stroke="Black"
StrokeDashArray="1 2"
StrokeThickness="1" />
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="CheckBoxStyle1"
TargetType="{x:Type CheckBox}">
<Setter Property="Foreground"
Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}" />
<Setter Property="Background"
Value="{StaticResource CheckBoxFillNormal}" />
<Setter Property="BorderBrush"
Value="{StaticResource CheckBoxStroke}" />
<Setter Property="BorderThickness"
Value="1" />
<Setter Property="FocusVisualStyle"
Value="{StaticResource EmptyCheckBoxFocusVisual}" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type CheckBox}">
<BulletDecorator SnapsToDevicePixels="true"
Background="Transparent">
<BulletDecorator.Bullet>
<Microsoft_Windows_Themes:BulletChrome Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
RenderMouseOver="{TemplateBinding IsMouseOver}" />
</BulletDecorator.Bullet>
<ContentPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
Margin="{TemplateBinding Padding}"
VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
RecognizesAccessKey="True" />
</BulletDecorator>
<ControlTemplate.Triggers>
<Trigger Property="HasContent"
Value="true">
<Setter Property="FocusVisualStyle"
Value="{StaticResource CheckRadioFocusVisual}" />
<Setter Property="Padding"
Value="4,0,0,0" />
</Trigger>
<Trigger Property="IsEnabled"
Value="false">
<Setter Property="Foreground"
Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<Grid>
<StackPanel>
<CheckBox x:Name="uiComboBox"
Content="Does not set the backing property, but responds to it.">
<CheckBox.Style>
<Style TargetType="{x:Type CheckBox}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type CheckBox}">
<BulletDecorator SnapsToDevicePixels="true"
Background="Transparent">
<BulletDecorator.Bullet>
<Microsoft_Windows_Themes:BulletChrome Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
RenderMouseOver="{TemplateBinding IsMouseOver}"
IsChecked="{Binding MyBoolean}">
</Microsoft_Windows_Themes:BulletChrome>
</BulletDecorator.Bullet>
<ContentPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
Margin="{TemplateBinding Padding}"
VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
RecognizesAccessKey="True" />
</BulletDecorator>
<ControlTemplate.Triggers>
<Trigger Property="HasContent"
Value="true">
<Setter Property="FocusVisualStyle"
Value="{StaticResource CheckRadioFocusVisual}" />
<Setter Property="Padding"
Value="4,0,0,0" />
</Trigger>
<Trigger Property="IsEnabled"
Value="false">
<Setter Property="Foreground"
Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</CheckBox.Style>
</CheckBox>
<TextBlock Text="{Binding MyBoolean, StringFormat=Backing property:{0}}" />
<CheckBox IsChecked="{Binding MyBoolean}"
Content="Sets the backing property." />
</StackPanel>
</Grid>
</Window>
And the code behind, with our backing Boolean value:
public partial class Window1 : Window, INotifyPropertyChanged
{
public Window1()
{
InitializeComponent();
this.DataContext = this;
}
private bool myBoolean;
public bool MyBoolean
{
get
{
return this.myBoolean;
}
set
{
this.myBoolean = value;
this.NotifyPropertyChanged("MyBoolean");
}
}
#region INotifyPropertyChanged Members
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(String info)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(info));
}
}
#endregion
}

I had a need for the AutoCheck functionality be off as well for a Checkbox/RadioButton, where I wanted to handle the Click event without having the control auto-check. I've tried various solutions here and on other threads and was unhappy with the results.
So I dug into what WPF is doing (using Reflection), and I noticed:
Both CheckBox & RadioButton inherit from the ToggleButton control primitive. Neither of them have a OnClick function.
The ToggleButton inherits from the ButtonBase control primitive.
The ToggleButton overrides the OnClick function and does: this.OnToggle(); base.OnClick();
ButtonBase.OnClick does 'base.RaiseEvent(new RoutedEventArgs(ButtonBase.ClickEvent, this));'
So basically, all I needed to do was override the OnClick event, don't call OnToggle, and do base.RaiseEvent
Here's the complete code (note that this can easily be reworked to do RadioButtons as well):
using System.Windows.Controls.Primitives;
public class AutoCheckBox : CheckBox
{
private bool _autoCheck = false;
public bool AutoCheck {
get { return _autoCheck; }
set { _autoCheck = value; }
}
protected override void OnClick()
{
if (_autoCheck) {
base.OnClick();
} else {
base.RaiseEvent(new RoutedEventArgs(ButtonBase.ClickEvent, this));
}
}
}
I now have a CheckBox that doesn't auto-check, and still fires the Click event. Plus I can still subscribe to the Checked/Unchecked events and handle things there when I programmatically change the IsChecked property.
One final note: unlike other solutions that do something like IsChecked != IsChecked in a Click event, this won't cause the Checked/Unchecked/Indeterminate events to fire until you programmatically set the IsChecked property.

This is the class I've written to do something similar, for similar reasons (still raises all the Click and Command events as normal, but does not alter the binding source by default and does not auto-toggle. Unfortunately it does still have the animated fade-in-out on click, which is a bit strange if the click-handling code doesn't end up changing IsChecked.
public class OneWayCheckBox : CheckBox
{
private class CancelTwoWayMetadata : FrameworkPropertyMetadata
{
protected override void Merge(PropertyMetadata baseMetadata,
DependencyProperty dp)
{
base.Merge(baseMetadata, dp);
BindsTwoWayByDefault = false;
}
}
static OneWayCheckBox()
{
// Remove BindsTwoWayByDefault
IsCheckedProperty.OverrideMetadata(typeof(OneWayCheckBox),
new CancelTwoWayMetadata());
}
protected override void OnToggle()
{
// Do nothing.
}
}
Usage:
<yourns:OneWayCheckBox IsChecked="{Binding SomeValue}"
Command="{x:Static yourns:YourApp.YourCommand}"
Content="Click me!" />
(Note that the IsChecked binding is now one-way by default; you can declare it as TwoWay if you want, but that would defeat part of the point.)

Late answer, but I just came across the question looking for something else.
What you want is not a checkbox with unusual behaviour at all, what you want is a button with unusual appearance. It's always easier to change the appearance of a control than its behaviour.
Something along these lines ought to do (untested)
<Button Command="{Binding CommandThatStartsTask}">
<Button.Template>
<ControlTemplate>
<CheckBox IsChecked="{Binding PropertySetByTask, Mode=OneWay}" />
</ControlTemplate>
</Button.Template>
</Button>

Use Validation to block the boolean from getting toggled when you don't want it to - http://www.codeproject.com/KB/WPF/wpfvalidation.aspx
This is much less scary than the other answer, or hooking Clicked

I've been trying to create my generic ReadOnlyCheckBox style/template but I'm having a problem with the binding to the data. In the example you bind directly to the data from the ControlTemplate definition, but of course this is not really what I want, as I want to be able to declare the new checkbox something like this:
<CheckBox x:Name="uiComboBox" Content="Does not set the backing property, but responds to it."
Style="{StaticResource ReadOnlyCheckBoxStyle}" IsChecked="{Binding MyBoolean}" Click="uiComboBox_Click"/>
Except of course when I do this and then set the event trigger on the bullet to be a TemplateBinding of IsChecked I have exactly what I started with! I guess I don't understand why setting the binding directly in the bullet is different from setting IsChecked and then binding to that, isn't the TemplateBinding just a way of referencing what is set in the properties of the control being created? How is the Click triggering the UI update even tho the data does not get updated? Is there a trigger for Click I can override to stop the update?
I got all the DictionaryResource stuff working fine so I am happy with that, cheers for the pointer.
The other thing I was curious about was if it is possible to reduce my Control/Style template by using the BasedOn parameter in the style, then I would only override the things I actually need to change rather than declaring a lot of stuff that I think is part of the standard template anyway. I might have a play with this.
Cheers
ed

If it helps anyone, a fast and elegant solution I've found is to hook with the Checked and Unchecked events and manipulate the value based on your flag.
public bool readOnly = false;
private bool lastValidValue = false;
public MyConstructor()
{
InitializeComponent();
contentCheckBox.Checked += new
RoutedEventHandler(contentCheckBox_Checked);
contentCheckBox.Unchecked += new
RoutedEventHandler(contentCheckBox_Checked);
}
void contentCheckBox_Checked(object sender, RoutedEventArgs e)
{
if (readOnly)
contentCheckBox.IsChecked = lastValidValue;
else
lastValidValue = (bool)contentCheckBox.IsChecked;
}

Wrap the CheckBox in a ContentControl. Make the ContentControl IsEnabled=False

Those two Properties are – IsHitTestVisible and Focusable
Make thse two properties to False. This makes the readonly checkbox in WPF.
So final XAML statement will be as follows for readonly checkbox in WPF –

Related

How can I disable WPF button highlight when mouse over or when clicked in runtime?

I've this code in C# to create a button as a child of a StackPanel:
`
Button myButton = new Button();
//All button stuff (Background, text...).
myStackPanel.Children.add(myButton);
`
But, as every button, it highlights every time the mouse is over or when I click it. Is there any way to change that in an easy code (I'm still new to C#) can remove that highlight.
I don't know how to do this. I haven't seen anything explaining this and the only codes I could find were in XAML, and I didn't understand them so couldn't translate them to C#.
The problem is all the code I find is about retemplating the XAML code. What I need is to do what I mentioned in C#, as the control is created from scratch in C#.
I took a look at a few of the answers for this and didn't see any I liked much.
WPF controls are lookless, meaning they have fixed behaviour but not specific look to them. You can re template a wpf control to pretty much anything you can describe in xaml. Many wpf controls have quite complicated templates.
Here's one way to template a button as described.
I've put this style in my window's resources. Usually such styles are in resource dictionaries which are merged in app.xaml.
<Window.Resources>
<Style x:Key="NoMouseOverButtonStyle" TargetType="{x:Type Button}">
<Setter Property="SnapsToDevicePixels" Value="true" />
<Setter Property="OverridesDefaultStyle" Value="true" />
<Setter Property="BorderBrush" Value="LightGray"/>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<Border x:Name="Border"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
Background="{TemplateBinding Background}" >
<ContentPresenter Margin="2"
HorizontalAlignment="Center"
VerticalAlignment="Center"
RecognizesAccessKey="True" />
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<Grid>
<Button Style="{StaticResource NoMouseOverButtonStyle}"
Content="This is my Button"
Click="Button_Click"
HorizontalAlignment="Left"
VerticalAlignment="Top"
/>
</Grid>
</Window>
The button references the style as a resource.
That style sets some defaults so the button has a border you can see but over ride.
The contentpresenter is critical because this is where whatever you make content of your button will appear.
If I set an actual value on a button then that will over ride the style.
Hence
<Button Style="{StaticResource NoMouseOverButtonStyle}"
Content="This is my Button"
Click="Button_Click"
HorizontalAlignment="Left"
VerticalAlignment="Top"
BorderBrush="Red"
/>
Gives me a red border on my button.
A lightgray border is rather simpler than a button has by default.
You could reproduce that. Maybe that'd be an interesting learning exercise.
Lookup the button template on msdn.
Google: "wpf button template msdn"
Take a look at that. Brace yourself - it is complicated.
See the button border brush is hard coded in the template?
Change the style above so it does the same.
Clue:
<Setter.Value>

Removing full screen in xaml dynamically

This will probably be very simple for most of you, I am new to XAML and WPF.
I have an app that startes att full screen, I did this by adding
WindowState="Maximized"
WindowStyle="None"
I want to have a button that simply eliminates this part. I have a "Full screen" button in the xaml and by click he is calling a "FullScreen_Click" function in my code.
I just need to know what to write in the code that will eliminate the full screen if it is on full screen mode and restore it to full screen when it is not.
Try this:
private void FullScreen_Click(object sender, RoutedEventArgs e)
{
WindowState = WindowState == WindowState.Maximized ? WindowState.Normal : WindowState.Maximized;
}
This will toggle between WindowState.Maximized and WindowState.Normal each time the Button is clicked.
For a xaml only technique just for reference to see a xaml example in comparison (but I would do #mm8's route, it's simpler);
1. Bind your property to that of another like:
<Window WindowState="{Binding Tag, ElementName=toggleState}" .... />
2. Use a `ToggleButton` or similar control and `Triggers`
.
<!-- like this PoC -->
<Grid>
<Grid.Resources>
<Style x:Key="cwWindowState_PoC" TargetType="{x:Type ToggleButton}">
<Setter Property="Tag" Value="Maximized"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ToggleButton">
<Grid>
<Border Background="{TemplateBinding Background}"/>
<ContentPresenter x:Name="MyContentPresenter"
Content="{TemplateBinding Tag}"
HorizontalAlignment="Center"
VerticalAlignment="Center" />
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsChecked" Value="True">
<Setter Property="Tag" Value="Normal" />
</Trigger>
<Trigger Property="IsChecked" Value="False">
<Setter Property="Tag" Value="Maximized" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Grid.Resources>
<ToggleButton x:Name="toggleState" Content="Click Me"
Background="Green"
Style="{StaticResource cwWindowState_PoC}"/>
</Grid>
Could also use DataTrigger but that requires interaction triggers instead of just a property setter from a template.

WPF Expander Templating - Display Content above ToggleButton

I'm about to create a new Expander Control (learning purpose) by creating different templates but can't figure out what I'm doing wrong...
ToggleButtonTemplate:
<ToggleButton>
<ToggleButton.Template>
<ControlTemplate TargetType="ToggleButton">
<Border x:Name="eBB" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}">
<Grid>
<Path x:Name="Sign" Data="M 0,10 L 7.5,2.5 L 15, 10" Stroke="Black" Width="15">
<Path.RenderTransform>
<RotateTransform Angle="0"/>
</Path.RenderTransform>
</Path>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsChecked" Value="True">
<Setter Property="Data" TargetName="Sign" Value="M 0,2.5 L 7.5,10 L 15,2.5"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Stroke" Value="#222" TargetName="Sign"/>
<Setter Property="Background" Value="#666" TargetName="eBB"/>
</Trigger>
<Trigger Property="IsPressed" Value="True">
<Setter Property="Stroke" Value="#FF003366" TargetName="Sign"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</ToggleButton.Template>
</ToggleButton>
Expander Template:
<Expander>
<Expander.Template>
<ControlTemplate TargetType="Expander">
<Grid>
<Grid.RowDefinitions>
<RowDefinition x:Name="ContentRow" Height="*"/>
<RowDefinition Height="20"/>
</Grid.RowDefinitions>
<ContentPresenter Grid.Row="0" Visibility="Collapsed" Content="{TemplateBinding Content}"/>
<local:FullSizeExpanderToggleButton Grid.Row="1" />
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsExpanded" Value="True">
<Setter Property="Visibility" Value="Visible"/>
<Setter Property="Height" Value="*" TargetName="ContentRow"/>
</Trigger>
<Trigger Property="IsExpanded" Value="False">
<Setter Property="Height" Value="0" TargetName="ContentRow"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Expander.Template>
</Expander>
Now when I want to add the Expander in my Main View:
<custom:FullSizeExpander Width="300">
<Button/>
</custom:FullSizeExpander>
the whole space inside the Control gets filled by the Button (the ToggleButton isn't visible anymore).
What am i doing wrong?
In addition I have some questions regarding this issue:
What does "ContentSource="Content"" do? What is it for? Whats different to "Content="{Templatebinding Content}""?
Does the Expander's Property "IsExpanded" get changed when the ToggleButtons Property "IsPressed" gets changed? What if there is no Togglebutton in the Expander at all?
first off, consider modifying your Expander template to look something like this:
<Expander>
<Rectangle Height="500" Width="500" Fill="Red"/>
<Expander.Template>
<ControlTemplate TargetType="Expander">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="20"/>
</Grid.RowDefinitions>
<ContentPresenter Grid.Row="0" x:Name="ContentPresenter"/>
<ToggleButton Grid.Row="1" IsChecked="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=IsExpanded}"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsExpanded" Value="True">
<Setter TargetName="ContentPresenter" Property="Visibility" Value="Visible"/>
</Trigger>
<Trigger Property="IsExpanded" Value="False">
<Setter TargetName="ContentPresenter" Property="Visibility" Value="Collapsed"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Expander.Template>
</Expander>
I'll explain how it works, and why it wasn't working before from the top-down.
First off, you'll want to actually put something in the expander to make sure it's working - i put a rectangle here with fixed sizes for now.
Next, i changed the first RowDefinition to be auto instead of *, as you want the expander to actually expand when opened. (rather than just hide its content in a big empty area). Auto uses exactly as much space as the content in the row needs, so when it's collapsed, that size will be 0, and when it's expanded, auto will become 500 to fit the rectangle.
The third thing i did was remove your bindings from the ContentPresenter. As it happens, Windows' content-bearing templates (as in anything that can have something else placed inside of it) will automatically look for the first ContentPresenter / ItemsPresenter tag inside its template and shove content into it.
As for the togglebutton however (i kept it simple and left it as a standard togglebutton), this one does actually need a binding.
What i did was a Relativesource Templatebinding to the property "IsExpanded".
Togglebuttons have 2 main states: "Checked" and "Unchecked" (true/false), and Expanders have 2 main states: "Expanded" and "Collapsed" (true/false).
So essentially all i did was tell the ToggleButton to share its true/false state of being checked or unchecked with the parent it sits inside of.
The full binding again is "{Binding RelativeSource={RelativeSource TemplatedParent}, Path=IsChecked}", which in english is essentially saying "Bind to a related source, and the related source is the parent you're in the template of, and bind so to said template;s "IsChecked" property.
Lastly i changed your triggers which were going the long way around to get the ContentPresenter to become hidden (trying to squash it by reducing the size of the Grid.Row it sits in), and instead just told it to hide when the expander's "IsExpanded" (and thanks to our binding, the ToggleButton's "IsChecked") is set to false, and the opposite when they're set to true.
.
As for your other questions:
1) The ContentSource is used to give the ContentPresenter an alias/alternate name, and i doubt you'll need it anytime soon. The property name is sort of misleading, i grant you.
2) As we saw above, no - the ToggleButton needs to be bound to the templated parent's "IsExpanded" property in order to work.
If you were to take the button out, the Expander simply would not work until you created a binding or made an instruction in code to tell it to open/close.

MouseLeftButtonDown event isn't fired in child ContentControl

I have PortItem which derived from ContentControl, TextedStackPanel derived from StackPanel which contains PortItems. And in MainWindow i have 2 StackPanels which contains TextedStackPanels . In PortItem i have overridden MouseLeftButtonDown method. But when i do this on this method isn't fired. I searched here in the forum, and found that Background property of Grid/StackPanel must be set to Transparent. I applied this, but there is no changes. What to do ?
EDIT 1
I use partial classes. I have 2 classes: PortItem.cs and PortItem.cs.xaml. I modifiy any visual changes in this XAML file.
EDIT 2
Also any mouse events aren't fired. Triggers which i use IsMouseOver are also dont work when i keep mouse on PortItem
XAML
<ContentControl x:Class="**.PortItem"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:UI="clr-namespace:**.UIData" Width="17" Height="17" Margin="3" SnapsToDevicePixels="True" >
<Grid Background="Transparent" Name="mainGrid">
<!-- transparent extra space makes connector easier to hit -->
<Rectangle Fill="Transparent" Margin="-2"/>
<Border BorderBrush="Green" x:Name="border" BorderThickness="2">
<Border.Style>
<Style>
<Style.Triggers>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Grid}, Path=IsMouseOver}" Value="True">
<Setter Property="Border.BorderBrush" Value="Blue"/>
</DataTrigger>
<DataTrigger Binding="{Binding IsSelected}" Value="True">
<Setter Property="Border.BorderBrush" Value="Blue"/>
</DataTrigger>
<!--<DataTrigger Binding="{Binding ContactPort}" Value="{x:Null}">
<Setter TargetName="border" Property="Border.BorderBrush" Value="Green"/>
</DataTrigger>-->
</Style.Triggers>
</Style>
</Border.Style>
<Image Source="/**;component/Resources/1337238611_port.png">
</Image>
</Border>
</Grid>
Make sure that you haven't set 'IsHitTestVisible' to false on your PortItem. Also, make sure no other controls are on top of it. If they are, set their 'IsHitTestVisible' property to false and then your PortItem control will get the mouse right click event. To make sure nothing is on top, declare your put your PortItem as the last thing added to your TextedStackPanel. To double check that nothing else is on top, change the background color of other controls to something really noticeable (just for testing) to see if anything is covering your PortItem control. Also, change the color on your PortItem control to verify that it is really where you think it is. Then once you get it all working, change the colors back to their original colors.
If you could give us a code sample of your XAML, that might help. If you're adding the PortItems dynamically in code behind, supply that code too.
Edit: in light of the changes you've made to your code, try to add ClipToBounds="False" to the top of your user control declaration.
<ContentControl x:Class="**.PortItem" ClipToBounds="False"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:UI="clr-namespace:**.UIData" Width="17" Height="17" Margin="3" SnapsToDevicePixels="True" >
Have you created a template for your PortItem? I created the follow class to replicate your PortItem and break point on the base.OnMouseButtonDown line and it fires, I think the reason your method is not executing is because there is no visual element for the mouse to actually interact with, try adding the style below to your app and you should see the method fire properly.
public class PortItem: ContentControl
{
protected override void OnMouseLeftButtonDown(MouseButtonEventArgs e)
{
base.OnMouseLeftButtonDown(e);
}
}
then in XAML I created a style to give it something to render.
<local:PortItem Margin="44,36,156,95">
<local:PortItem.Style>
<Style TargetType="{x:Type local:PortItem}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:PortItem}">
<Border Background="Transparent">
<ContentPresenter Content="{TemplateBinding Content}"/>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</local:PortItem.Style>
</local:PortItem>
The background being Transparent that you mention you can see in the border control, if you leave the background out you are correct, the event never fires.

Fixed text in TextBox

How can I dynamically add fixed text to a TextBox? By "fixed text", I mean text which can't be deleted by the user's input.
For example, the path in CMD:
C:\Program Files>cd ..
C:\>
I'm assuming that you want an editable textbox, that has some fixed text at the start of it that the user cannot edit. If so then this seems to work - it's based on the standard textbox style as extracted in Blend...
You need to have the following namespace declaration in your xaml root:
xmlns:Microsoft_Windows_Themes="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Aero"
Then use this template:
<ControlTemplate TargetType="{x:Type TextBox}">
<Microsoft_Windows_Themes:ListBoxChrome x:Name="Bd" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" RenderMouseOver="{TemplateBinding IsMouseOver}" RenderFocused="{TemplateBinding IsKeyboardFocusWithin}" SnapsToDevicePixels="true">
<StackPanel Orientation="Horizontal">
<TextBlock VerticalAlignment="Center">This is fixed:</TextBlock>
<ScrollViewer x:Name="PART_ContentHost" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</StackPanel>
</Microsoft_Windows_Themes:ListBoxChrome>
<ControlTemplate.Triggers>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Background" TargetName="Bd" Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}"/>
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
If you were to wrap this in a custom control or user control, you could programmatically set the fixed text through a custom property.
TextBox IsReadOnly = true when you populate the text dynamically? if you use MVVM bind IsReadOnly to a property in your ViewModel, when that ViewModel populates the text
You can use a textblock instead.
If You have to use a textbox, you can do it Read Only changing the IsReadOnly property to "True"
private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
if (textBox1.SelectionStart < LengthOfFixedString)
e.SuppressKeyPress = true;
}

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