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How do I make a textbox visible and hidden with a checkbox?

So I am trying to make my textbox invisible when a checkbox is not checked. Everything works fine untill I check the box and then uncheck it again. The textbox will stay visible.
private void chbon_Checked_1(object sender, RoutedEventArgs e)
{
if (cchbon.IsChecked == true)
{
txtshow.Visibility = System.Windows.Visibility.Visible;
}
if (chbon.IsChecked == false)
{
txtshow.Visibility = System.Windows.Visibility.Hidden;
}
}
This is the XAML for the Checkbox:
<CheckBox x:Name="chbon" Content="On" HorizontalAlignment="Left" Margin="175,84,0,0" VerticalAlignment="Top" Checked="chbon_Checked_1"/>
<TextBox x:Name="txtshow" HorizontalAlignment="Left" Height="23" Margin="272,82,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="29" Visibility="Hidden"/>

The event Checked does not fire when uncheck happens.
The event Unchecked is for that purpose.
... Checked="chbon_Checked" Unchecked="chbon_Unchecked"/>
and no need to monitor cchbon.IsChecked in code behind:
private void chbon_Checked(object sender, RoutedEventArgs e)
{
txtshow.Visibility = System.Windows.Visibility.Visible;
}
private void chbon_Unchecked(object sender, RoutedEventArgs e)
{
txtshow.Visibility = System.Windows.Visibility.Hidden;
}
Alternatively, you can do it via binding and a converter:
<Window.Resources>
<BooleanToVisibilityConverter x:Key="BoolToVis"/>
</Window.Resources>
...
<CheckBox x:Name="chbon"/>
<TextBox x:Name="txtshow" Visibility="{Binding ElementName=chbon, Path=IsChecked,
Converter={StaticResource BoolToVis}, FallbackValue=Hidden}"/>
Note that,
Once you managed this approach you may want to implement a custom converter since the built-in BooleanToVisibilityConverter returns Visible/Collapsed for True/False input (and not Visible/Hidden)

The Checked event handler will only hit when you check the checkbox, not uncheck it. You can also use the Unchecked handler in your XAML that would make the textbox hidden.
private void chbon_Unchecked(object sender, RoutedEventArgs e)
{
txtshow.Visibility = System.Windows.Visibility.Hidden;
}
private void chbon_Checked_1(object sender, RoutedEventArgs e)
{
txtshow.Visibility = System.Windows.Visibility.Visible;
}

when CheckBox goes to unchecked state, Unchecked event fires (simmetric to Checked). Add event handler to both of them.
<CheckBox x:Name="chbon"
Content="On"
HorizontalAlignment="Left"
Margin="175,84,0,0"
VerticalAlignment="Top"
Checked="chbon_Checked_1"
Unhecked="chbon_Checked_1"/>
private void chbon_Checked_1(object sender, RoutedEventArgs e)
{
txtshow.Visibility = cchbon.IsChecked ? Visibility.Visible : Visibility.Hidden;
}
It is common to use binding to boolean property to set Visibility of some element. There is a BooleanToVisibilityConverter in .NET, which returns Visible for true, and Collapsed for false. Collapsed is different from Hidden: Hidden element stil claims the space on the screen as if it was Visible.
There is a way to achieve everything in XAML using a Trigger:
<CheckBox x:Name="chbon" Content="On"
HorizontalAlignment="Left" Margin="175,84,0,0" VerticalAlignment="Top"/>
<TextBox x:Name="txtshow"
HorizontalAlignment="Left" VerticalAlignment="Top"
Height="23" Width="29" Margin="272,82,0,0" TextWrapping="Wrap">
<TextBox.Style>
<Style TargetType="TextBox">
<Setter Property="Visibility" Value="Hidden"/>
<Style.Triggers>
<DataTrigger Binding="{Binding IsChecked, ElementName=chbon}" Value="True">
<Setter Property="Visibility" Value="Visible"/>
</DataTrigger>
</Style.Triggers>
</Style>
</TextBox.Style>
<TextBox/>

How do I get a DatePicker to only accept numeric input in WPF?

I have the following DatePicker control:
<Grid x:Name="LayoutRoot" Background="White">
<DatePicker Margin="2" Grid.Column="1" VerticalAlignment="Center"/>
</Grid>
Is it possible to allow user only to set numeric input? Or how to disable the Textbox input in case it's not possible to acheive

This code only allows to enter numeric values in DatePicker
XAML:
<DatePicker Margin="2" Grid.Column="1"
PreviewTextInput="phoneNumber_PreviewTextInput"
VerticalAlignment="Center"/>
Code behind
private void phoneNumber_PreviewTextInput(object sender, TextCompositionEventArgs e)
{
char character = Convert.ToChar(e.Text);
if (char.IsNumber(character))
{
e.Handled = false;
}
else
{
e.Handled = true;
}
}

Try this one:
<DatePicker Margin="2" Grid.Column="1" VerticalAlignment="Center">
<DatePicker.Resources>
<Style TargetType="DatePickerTextBox">
<Setter Property="IsReadOnly" Value="True"/>
</Style>
</DatePicker.Resources>
</DatePicker>
</Grid>

Actually I appreciate your answers and I really enjoy them but I would like the solution I found, in fact I used the Regex and below is the used code :
private bool IsTextAllowed(string text)
{
Regex regex = new Regex("[^0-9/]+");
return !regex.IsMatch(text);
}
private void DatePicker_PreviewTextInput(object sender, TextCompositionEventArgs e)
{
e.Handled = !IsTextAllowed(e.Text);
}

Open Buttons ContextMenu on Left Click

I have a button with a context menu, my requirements are to show the context menu on left click
The problem is that the <ContextMenu ItemsSource="{Binding LineItems}" isn't being updated/refresh when the context menu opens. However If i right click first, items are loaded fine
XAML
<Button x:Name="BtnMessageChannel" Click="BtnMessageChannel_Click" Grid.Row="0" Grid.Column="2" Height="23" Width="23" ToolTip="Message Channel" >
<Button.ContextMenu>
<ContextMenu ItemsSource="{Binding LineItems}" x:Name="CtxMessageChannel">
<ContextMenu.Resources>
<Image x:Key="img" Source="{Binding Icon}" x:Shared="false"/>
<Style TargetType="{x:Type MenuItem}">
<Setter Property="Header" Value="{Binding DisplayName}"/>
<Setter Property="Icon" Value="{StaticResource img}">
</Setter>
</Style>
</ContextMenu.Resources>
</ContextMenu>
</Button.ContextMenu>
<Image Source="Images/mail_send.png" HorizontalAlignment="Left" Width="16" />
</Button>
Code Behind
private void BtnMessageChannel_Click(object sender, RoutedEventArgs e)
{
BtnMessageChannel.ContextMenu.GetBindingExpression(ContextMenu.ItemsSourceProperty)
.UpdateTarget();
BtnMessageChannel.ContextMenu.Visibility = Visibility.Visible;
BtnMessageChannel.ContextMenu.IsOpen = true;
}
Is there any easy solutions to this problem?

An easy solution is to update your button event handler to simulate a right click if the context menu is not currently open.
private void BtnMessageChannel_Click(object sender, RoutedEventArgs e)
{
if (!BtnMessageChannel.ContextMenu.IsOpen)
{
e.Handled = true;
var mouseRightClickEvent = new MouseButtonEventArgs(Mouse.PrimaryDevice, Environment.TickCount, MouseButton.Right)
{
RoutedEvent = Mouse.MouseUpEvent,
Source = sender,
};
InputManager.Current.ProcessInput(mouseRightClickEvent);
}
}

Replicating standard system menu with WindowChrome?

When using WindowChrome (downloadable here) to customize the nonclient area of a window, a natural starting point is to make a title bar that looks and acts identical to a standard title bar. This requires adding a "fake" application icon and title bar, because apparently WindowChrome disables those features (the minimize, maximize and close buttons still work.)
Here's what I have so far:
<Window x:Class="MyApp.MainWindow"
x:Name="MainWindowItself"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:shell="clr-namespace:Microsoft.Windows.Shell;assembly=Microsoft.Windows.Shell"
xmlns:local="clr-namespace:MyApp"
Title="My Application" Icon="App.ico" Height="350" Width="525">
<Window.Resources>
<Style TargetType="{x:Type local:MainWindow}">
<Setter Property="shell:WindowChrome.WindowChrome">
<Setter.Value>
<shell:WindowChrome />
</Setter.Value>
</Setter>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:MainWindow}">
<Grid>
<Border Background="White" Margin="{Binding Source={x:Static shell:SystemParameters2.Current}, Path=WindowNonClientFrameThickness}">
<ContentPresenter Content="{TemplateBinding Content}" />
</Border>
<TextBlock Text="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Title}"
VerticalAlignment="Top" HorizontalAlignment="Left"
Margin="32,8,0,0"/>
<Image x:Name="SystemMenuIcon" Source="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Icon}"
VerticalAlignment="Top" HorizontalAlignment="Left"
Margin="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=(shell:WindowChrome.WindowChrome).ResizeBorderThickness}"
Width="{Binding Source={x:Static shell:SystemParameters2.Current}, Path=SmallIconSize.Width}"
shell:WindowChrome.IsHitTestVisibleInChrome="True" MouseDown="SystemMenuIcon_MouseDown">
</Image>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<Grid>
<TextBlock Text="Client area content goes here"/>
</Grid>
</Window>
Code behind:
private void SystemMenuIcon_MouseDown(object sender, MouseButtonEventArgs e)
{
var offs = SystemParameters2.Current.WindowNonClientFrameThickness;
SystemCommands.ShowSystemMenu(this, new Point(Left + offs.Left, Top + offs.Top));
}
This comes very close to working. The first problem is that after you click the application icon and the system menu appears, the menu should disappear if you click a second time--instead, the menu just redraws. Also, if you double-click then the window should close, but Image doesn't have a double-click event. How would you suggest adding these features?

To disable working of standard Chrome Buttons Just add an extra attribute CaptionHeight="0" in your XAML code of shell:WindowsChrome
So it will be like that
<Setter Property="shell:WindowChrome.WindowChrome">
<Setter.Value>
<shell:WindowChrome CaptionHeight="0" />
</Setter.Value>
</Setter>
To make a fake Chrome. Modify the Template to like this:
<ControlTemplate TargetType="Window">
<AdornerDecorator>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="35" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<Grid x:Name="PART_Chrome" shell:WindowChrome.IsHitTestVisibleInChrome="True">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="50" />
<ColumnDefinition Width="*" />
<ColumnDefinition Width="105" />
</Grid.ColumnDefinitions>
<Image Source="Application Favicon Path" />
<TextBlock Grid.Column="1" Text="{TemplateBinding Title}" VerticalAlignment="Center" />
<StackPanel Orientation="Horizontal" Grid.Column="3" >
<Button Command="{Binding Source={x:Static shell:SystemCommands.MinimizeWindowCommand}}" >
<Path Data="M0,6 L8,6 Z" Width="8" Height="7" VerticalAlignment="Center" HorizontalAlignment="Center"
Stroke="{Binding Foreground, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Button}}" StrokeThickness="2" />
</Button>
<Button x:Name="MaximizeButton" Command="{Binding Source={x:Static shell:SystemCommands.MaximizeWindowCommand}}" >
<Path Data="M0,1 L9,1 L9,8 L0,8 Z" Width="9" Height="8" VerticalAlignment="Center" HorizontalAlignment="Center"
Stroke="{Binding Foreground, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Button}}" StrokeThickness="2" />
</Button>
<Button x:Name="RestoreButton" Command="{Binding Source={x:Static shell:SystemCommands.RestoreWindowCommand}}" >
<Path Data="M2,0 L8,0 L8,6 M0,3 L6,3 M0,2 L6,2 L6,8 L0,8 Z" Width="8" Height="8" VerticalAlignment="Center" HorizontalAlignment="Center"
Stroke="{Binding Foreground, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Button}}" StrokeThickness="1" />
</Button>
<Button Command="{Binding Source={x:Static shell:SystemCommands.CloseWindowCommand}}" >
<Path Data="M0,0 L8,7 M8,0 L0,7 Z" Width="8" Height="7" VerticalAlignment="Center" HorizontalAlignment="Center"
Stroke="{Binding Foreground, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Button}}" StrokeThickness="1.5" />
</Button>
</StackPanel>
</Grid>
<ContentPresenter Grid.Row="1" Content="{TemplateBinding Content}" />
</Grid>
</AdornerDecorator>
<ControlTemplate.Triggers>
<Trigger Property="WindowState" Value="Normal">
<Setter Property="Visibility" Value="Collapsed" TargetName="RestoreButton" />
<Setter Property="Visibility" Value="Visible" TargetName="MaximizeButton" />
</Trigger>
<Trigger Property="WindowState" Value="Maximized">
<Setter Property="Visibility" Value="Visible" TargetName="RestoreButton" />
<Setter Property="Visibility" Value="Collapsed" TargetName="MaximizeButton" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
Also do command binding for proper working of Fake Chrome bar
public MainWindow()
{
this.CommandBindings.Add(new CommandBinding(SystemCommands.CloseWindowCommand, OnCloseWindow));
this.CommandBindings.Add(new CommandBinding(SystemCommands.MaximizeWindowCommand, OnMaximizeWindow, OnCanResizeWindow));
this.CommandBindings.Add(new CommandBinding(SystemCommands.MinimizeWindowCommand, OnMinimizeWindow, OnCanMinimizeWindow));
this.CommandBindings.Add(new CommandBinding(SystemCommands.RestoreWindowCommand, OnRestoreWindow, OnCanResizeWindow));
}
private void OnCanMinimizeWindow(object sender, CanExecuteRoutedEventArgs e)
{
e.CanExecute = this.ResizeMode != ResizeMode.NoResize;
}
private void OnCanResizeWindow(object sender, CanExecuteRoutedEventArgs e)
{
e.CanExecute = this.ResizeMode == ResizeMode.CanResize || this.ResizeMode == ResizeMode.CanResizeWithGrip;
}
private void OnCloseWindow(object sender, ExecutedRoutedEventArgs e)
{
Microsoft.Windows.Shell.SystemCommands.CloseWindow(this);
}
private void OnMaximizeWindow(object sender, ExecutedRoutedEventArgs e)
{
Microsoft.Windows.Shell.SystemCommands.MaximizeWindow(this);
}
private void OnMinimizeWindow(object sender, ExecutedRoutedEventArgs e)
{
Microsoft.Windows.Shell.SystemCommands.MinimizeWindow(this);
}
private void OnRestoreWindow(object sender, ExecutedRoutedEventArgs e)
{
Microsoft.Windows.Shell.SystemCommands.RestoreWindow(this);
}

My xaml is not exactly alike (I do not use WindowChrome but my own and I have a titlebar template), but I had the exact same problem and the solution should be usable for you as well.
First the easy one: for the doubleclick to work just use the ClickCount.
Then, geting the menu disappear requires keeping some state telling whether it is currently active or not: the trick is that different events are fired on the second click (as figured out by using Snoop. The first click is only a MousweDown, the second is MouseDown followed by MouseUp (my guess is that the up from the first click is handled by the sysmenu).
private bool inSysMenu = false;
void SystemMenuIcon_MouseDown( object sender, MouseButtonEventArgs e )
{
if( e.ClickCount == 1 && !inSysMenu )
{
inSysMenu = true;
ShowSystemMenu(); //replace with your code
}
else if( e.ClickCount == 2 && e.ChangedButton == MouseButton.Left )
{
window.Close();
}
}
void SystemMenuIcon_MouseLeave( object sender, MouseButtonEventArgs e )
{
inSysMenu = false;
}
void SystemMenuIcon_MouseUp( object sender, MouseButtonEventArgs e )
{
inSysMenu = false;
}

Display pictures as hide or visible

Goal:
When user start typing text or characters in the textbox txtSearch the picture picEnlarger will be hidden and be replaced by picture picXmark.
In default, the picEnlarger will always display until input data will be applied in the textbox txtSearch. In order word, no data in textbox then display picEnlarger and hide picXmark.
Problem:
Having problem to display the picture picXmark and hide the picture picEnlarger when the user start typing characters in the textbox named txtSearch.
When I tried coding in C# to gain this functionality no effect would occur in the run time.
I tried using the code:
picEnlarger = new Image();
picXmark = new Image();
But no effect has happened.
XAML code from Stock.xaml:
<Canvas Height="39.667" Margin="8,0,215.397,0" VerticalAlignment="Top">
<Button x:Name="btnNewProduct" Content="New" Width="75" Click="btnNewProduct_Click" Height="20.277" RenderTransformOrigin="0.667,1.726" d:LayoutOverrides="VerticalAlignment, Margin" Canvas.Left="0.001" Canvas.Top="18.723" />
<Button x:Name="btnAddDelivery" Content="Add quantity" Width="75" Click="btnAddDelivery_Click" d:LayoutOverrides="VerticalAlignment, Margin" Height="20.277" Canvas.Left="79.001" Canvas.Top="18.723" />
<Button x:Name="btnDeleteProduct" Content="Delete" Width="75" RenderTransformOrigin="0.107,1.843" Click="btnDeleteProduct_Click" Height="20.277" Canvas.Left="158.001" d:LayoutOverrides="HorizontalAlignment, VerticalAlignment, Width" Canvas.Top="18.723" />
<Button x:Name="btnEdit" Content="Edit" Canvas.Left="237.001" Width="75" Canvas.Top="18.723" Click="btnEdit_Click" />
<TextBox Name="txtSearch" Canvas.Left="391.36" TextWrapping="Wrap" Canvas.Top="18.723" Width="143.243" TextChanged="txtSearch_TextChanged" Text=" Search article" PreviewMouseLeftButtonDown="txtSearch_PreviewMouseLeftButtonDown" TextInput="txtSearch_TextInput">
</TextBox>
<Label Content="Advanced Search" HorizontalAlignment="Left" Canvas.Left="444.289"/>
<Image x:Name="picXmark" Height="8" Source="/MediaStore;component/Bilder/search_xmark.gif" Stretch="Fill" Width="8" Canvas.Left="519.853" Canvas.Top="24.167" Visibility="Hidden" />
<Image x:Name="picEnlarger" Height="14" Canvas.Left="513.75" Source="/MediaStore;component/Bilder/search_enlarger2.gif" Stretch="Fill" Canvas.Top="21.527" Width="14" Visibility="Hidden" ImageFailed="picEnlarger_ImageFailed" />
</Canvas>
Class Stock
private void txtSearch_TextChanged(object sender, TextChangedEventArgs e)
{
picEnlarger = new Image();
picXmark = new Image();
if (txtSearch.Text != "")
{
picEnlarger.Visibility = Visibility.Collapsed;
picXmark.Visibility = Visibility.Visible;
RegularSearch myRegularSearch = new RegularSearch();
myRegularSearch.Test(txtSearch.Text);
}
else
{
picEnlarger.Visibility = Visibility.Visible;
picXmark.Visibility = Visibility.Hidden;
}
}
private void txtSearch_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
txtSearch.Text = "";
}

In theory you should be able to just use triggers for that, e.g.
<TextBox Name="txtSearch" />
<Image Name="ImageOne">
<Image.Style>
<Style TargetType="{x:Type Image}">
<Setter Property="Visibility" Value="Visible" />
<Style.Triggers>
<DataTrigger Binding="{Binding Text, ElementName=txtSearch}"
Value="">
<Setter Property="Visibility" Value="Hidden" />
</DataTrigger>
</Style.Triggers>
</Style>
</Image.Style>
</Image>
<Image Name="ImageOne">
<Image.Style>
<Style TargetType="{x:Type Image}">
<Setter Property="Visibility" Value="Hidden" />
<Style.Triggers>
<DataTrigger Binding="{Binding Text, ElementName=txtSearch}"
Value="">
<Setter Property="Visibility" Value="Visible" />
</DataTrigger>
</Style.Triggers>
</Style>
</Image.Style>
</Image>
When text is entered one image will become visible while the other one will be hidden.