Develop Reference

WPF | Control Menu Checkbox (C#)

I've created a controll menu in WPF. The button in that menu should activate the "Dark mode" that I've already created. Well that's just a simple Click event.
But I'd like to have a CheckBox not a simple Click event.
That's my code in XAML:
<DockPanel>
<Menu DockPanel.Dock="Top">
<MenuItem Header="_Settings">
<MenuItem Header="_Darkmode" />
</MenuItem>
</Menu>
</DockPanel>
The C# Code is inconsequential because that's just a sample.
Greetings from the US

Instead of using the Click event:
<Menu>
<MenuItem Header="_Settings">
<MenuItem Header="_Darkmode"
Click="OnDarkmodeClicked"/>
</MenuItem>
</Menu>
You could use the Checked/Unchecked events after setting the IsCheckable property:
<Menu>
<MenuItem Header="_Settings">
<MenuItem Header="_Darkmode"
IsCheckable="True"
Checked="OnDarkmodeChecked"
Unchecked="OnDarkmodeUnchecked"/>
</MenuItem>
</Menu>
Or you could bind IsChecked to a property in your model:
<Menu>
<MenuItem Header="_Settings">
<MenuItem Header="_Darkmode"
IsCheckable="True"
IsChecked="{Binding UseDarkmode}"/>
</MenuItem>
</Menu>

This may not be the best solution, but you could store a boolean elsewhere, and have a menuitem that looks like this:
XAML code
<MenuItem Header="_Blur Background" IsCheckable="True" IsChecked="True" Click="BlurOnOff_Click" InputGestureText="Ctrl+B"></MenuItem>
Then C# code
private void BlurOnOff_Click(object sender, RoutedEventArgs e)
{
blurOn = blurOn ? false : true;
}
The Blur On/Off is just an example. When the function is called, it updates the boolean to be the opposite of what it was before.

WPF MenuItem multi adding.

Error CS0120 An object reference is required for the non-static field,
method, or property 'MainWindow.System' %Path%\MainWindow.g.cs at line
316
I get the code error i mentioned on title when i try to add Sub MenuItems under a SubMenuItem. Here is my Code:
<Menu x:Name="MainMenu" Height="Auto" Width="Auto" VerticalAlignment="Top">
<MenuItem Header="_Menu" x:Name="Menu" Foreground="Black">
<MenuItem x:Name="RestartComputer" Header="_Restart Computer" Click="restart_Click"/>
<MenuItem x:Name="ShutdownComputer" Header="_Shutdown Computer" Click="shutdown_Click"/>
<MenuItem x:Name="OnTop" Header="_Always On Top" Click="OnTop_Click"/>
<Separator Width="Auto" Height="2"/>
<MenuItem x:Name="Exit" Header="_Exit" Click="MenuItem_Click"/>
</MenuItem>
<MenuItem x:Name="ControlPanel" Header="_Control Panel" Height="Auto" Width="Auto" Foreground="Black">
<MenuItem x:Name="Main" Header="Control Panel Main"/>
<MenuItem x:Name="ProgramsAndFeatures" Header="Programs and Features"/>
<MenuItem x:Name="AdministrativeTools" Header="Administrative Tools"/>
<MenuItem x:Name="DeviceManager" Header="Device Manager"/>
<MenuItem x:Name="NetworkAndSharing" Header="Network and Sharing"/>
<MenuItem x:Name="PowerOptions" Header="Power Options"/>
<Separator Width="Auto" Height="2"/>
<MenuItem x:Name="WindowsFirewall" Header="Windows Firewall"/>
<MenuItem x:Name="Display" Header="Display"/>
<Separator Width="Auto" Height="2"/>
<MenuItem x:Name="System" Header="System"/>
<MenuItem x:Name="DevicesAndPrinters" Header="Devices and Printers"/>
</MenuItem>
</Menu>
If i lessen these MenuItems under ControlPanel menu item to 4 or 5 no problem, but if i make them more than 5 or 6 i get the error what can it be ?
And also at MainWindow.g.cs line 316 is this.
[System.ComponentModel.EditorBrowsableAttribute(System.ComponentModel.EditorBrowsableState.Never)]

Use different x:Name for
<MenuItem x:Name="System" Header="System"/>

Create Vertical Menu

I am try do a menu like the photo below:
I have this code:
<Menu >
<Menu.ItemsPanel>
<ItemsPanelTemplate>
<VirtualizingStackPanel Orientation="Vertical"/>
</ItemsPanelTemplate>
</Menu.ItemsPanel>
<MenuItem Header="Item1">
<MenuItem Header="SubItem 1">
<MenuItem Header="SubItem 1.1"></MenuItem>
<MenuItem Header="SubItem 1.2"></MenuItem>
<MenuItem Header="SubItem 1.3"></MenuItem>
<MenuItem Header="SubItem 1.4"></MenuItem>
</MenuItem>
<MenuItem Header="SubItem 2"></MenuItem>
<MenuItem Header="SubItem 3"></MenuItem>
<MenuItem Header="SubItem 4"></MenuItem>
</MenuItem>
<MenuItem Header="Item2">
<MenuItem Header="SubItem 1"></MenuItem>
<MenuItem Header="SubItem 2"></MenuItem>
<MenuItem Header="SubItem 3"></MenuItem>
</MenuItem>
</Menu>
but this code returns a menu like in the pictures below:
First appears this:
and when I put the mouse hover the Item 1 appears like this:
I want to that the second level of the Menu open on the right side of the first, like in the first image.

You have to create a custom template for your Menu to achieve your goal.
Here is the default ControlTemplate for Menu, I think the easiest way is to start from that. You will have to add HorizontalOffset and VerticalOffset for the PopUp in the TopLevelHeader template, so you can align it to your needs (or simply set Placement to Right - which is easier in my opinion).
Also, you should set a Width for your menu (either directly or by placing it inside some container that restricts it's Width), otherwise it will take up all the space and the PopUp might not be visible .
I will not replicate the whole XAML here, but here is the important part:
// ...
<!-- TopLevelHeader -->
<ControlTemplate x:Key="{x:Static MenuItem.TopLevelHeaderTemplateKey}"
TargetType="MenuItem">
<Border Name="Border" >
<Grid>
<ContentPresenter
Margin="6,3,6,3"
ContentSource="Header"
RecognizesAccessKey="True" />
<Popup
Name="Popup"
Placement="Right" <!-- This is modified -->
IsOpen="{TemplateBinding IsSubmenuOpen}"
AllowsTransparency="True"
Focusable="False"
PopupAnimation="Fade">
// ... (You need all the XAML from the linked MSDN site in your Resources somewhere)
After that you can use your Menu almost exactly like you did (I only added Width):
<Menu Width="300">
<Menu.ItemsPanel>
<ItemsPanelTemplate>
<VirtualizingStackPanel Orientation="Vertical"/>
</ItemsPanelTemplate>
</Menu.ItemsPanel>
<MenuItem Header="Item1">
<MenuItem Header="SubItem 1">
<MenuItem Header="SubItem 1.1"></MenuItem>
<MenuItem Header="SubItem 1.2"></MenuItem>
<MenuItem Header="SubItem 1.3"></MenuItem>
<MenuItem Header="SubItem 1.4"></MenuItem>
</MenuItem>
<MenuItem Header="SubItem 2"></MenuItem>
<MenuItem Header="SubItem 3"></MenuItem>
<MenuItem Header="SubItem 4"></MenuItem>
</MenuItem>
<MenuItem Header="Item2">
<MenuItem Header="SubItem 1"></MenuItem>
<MenuItem Header="SubItem 2"></MenuItem>
<MenuItem Header="SubItem 3"></MenuItem>
</MenuItem>
</Menu>
You might want to name the template and apply it to this Menu directly, not to mess up other Menus in your app...
The result:
Of course some more styling is needed to get the exact result you want, but I hope you got the idea.

Bind WPF combobox submenu item to combobox selecteditem

Inside this combobox I have a menu that contains multiple menus.
This is how it looks:
This is the XAML:
<ComboBox>
<Menu>
<MenuItem Header="Name">
<MenuItem Header="Last" />
<MenuItem Header="First" />
</MenuItem>
</Menu>
<Menu>
<MenuItem Header="Age">
<MenuItem Header="20" />
<MenuItem Header="24" />
</MenuItem>
</Menu>
</ComboBox>
When the user selects "Last"/"First"/"20"/"24" I want the combobox to set its selected item to one of this 4 items.
Is it possible? If yes, how can I do it?

Yes you can do that. But I am not sure if this is the best way cos I dont know your requirement in full.
XAML:
<ComboBox x:Name="cmb1" IsEditable="True" >
<Menu>
<MenuItem Header="Name" >
<MenuItem Click="MenuItem_Click" CommandParameter ="Last" Header="Last"/>
<MenuItem Click="MenuItem_Click" CommandParameter="First" Header="First" />
</MenuItem>
</Menu>
<Menu>
<MenuItem Header="Age">
<MenuItem Header="20" />
<MenuItem Header="24" />
</MenuItem>
</Menu>
</ComboBox>
vb Code:
Private Sub MenuItem_Click(sender As Object, e As RoutedEventArgs)
Me.cmb1.Text = CType(sender, MenuItem).CommandParameter.ToString()
End Sub
c# code :
private void MenuItem_Click(object sender, RoutedEventArgs e)
{
MenuItem menuItem = sender as MenuItem;
this.cmb1.Text = menuItem.CommandParameter.ToString();
}

WPF find a nested menuitem in code

I have an image that has a nested context menu defined in the XAML (shown below).
I am trying to use a for loop to find a menu and uncheck it using IsChecked=false.
my code is as follows:
for (int i = 1; i <= 16; i++)
{
MenuItem theMenu = (MenuItem)this.FindName("beat" + i.ToString());
theMenu.IsChecked = false;
}
the above does not work and returns a null.
what am I doing wrong!
excerpt from the XAML
<Image x:Name="Options" Height="35" Source="Images/pad-options-button.png" Stretch="Fill" Width="47" Canvas.Left="740" Canvas.Top="293"
MouseUp="Options_MouseUp">
<Image.ContextMenu>
<ContextMenu>
<MenuItem Header="Beats">
<MenuItem Name="beat1" Header="1" Click="MenuBeats_Click"/>
<MenuItem Name="beat2" Header="2" Click="MenuBeats_Click"/>
<MenuItem Name="beat3" Header="3" Click="MenuBeats_Click"/>
<MenuItem Name="beat4" Header="4" Click="MenuBeats_Click"/>
<MenuItem Name="beat5" Header="5" Click="MenuBeats_Click"/>
<MenuItem Name="beat6" Header="6" Click="MenuBeats_Click"/>
<MenuItem Name="beat7" Header="7" Click="MenuBeats_Click"/>
<MenuItem Name="beat8" Header="8" Click="MenuBeats_Click"/>/>
<MenuItem Name="beat9" Header="9" Click="MenuBeats_Click"/>
<MenuItem Name="beat10" Header="10" Click="MenuBeats_Click"/>
<MenuItem Name="beat11" Header="11" Click="MenuBeats_Click"/>
<MenuItem Name="beat12" Header="12" Click="MenuBeats_Click"/>
<MenuItem Name="beat13" Header="13" Click="MenuBeats_Click"/>
<MenuItem Name="beat14" Header="14" Click="MenuBeats_Click"/>
<MenuItem Name="beat15" Header="15" Click="MenuBeats_Click"/>
<MenuItem Name="beat16" Header="16" Click="MenuBeats_Click"/>
</MenuItem>
<MenuItem Header="Beat Type">
<MenuItem Name="Whole" Header="Whole" Click="MenuBeatType_Click"/>
<MenuItem Name ="Half" Header="Half" Click="MenuBeatType_Click"/>
<MenuItem Name ="Quarter" Header="Quarter" Click="MenuBeatType_Click"/>
<MenuItem Name ="Eighth" Header="Eighth" Click="MenuBeatType_Click"/>
<MenuItem Name ="Sixteenth" Header="Sixteenth" Click="MenuBeatType_Click"/>
</MenuItem>
</ContextMenu>
</Image.ContextMenu>
</Image>
</Canvas>

An other option is to get the context menu from the image.
var items = Options.ContextMenu.Items
foreach(MenuItem item in items)
{
// do your work with the item
}
Be arware that you will have to handle the sub items!
Items will have only 2 items in your case

You have incorrect markup. Last two symbols shouldn't be there:
<MenuItem Name="beat8" Header="8" Click="MenuBeats_Click"/>/>
However, you example perfectly works for me, but with accidental item:
"/>"

Just in the constructor of the class in code behind write NameScope.SetNameScope(contextMenu, NameScope.GetNameScope(this)); contextMenu is the name given to context menu of image. Actually ContextMenu is not the part of Visual tree so it cant find the names . but the above line of code will set context menu in the scope of visual tree and hence will find the names. Hope this will help.