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WPF call Window_Closing event from code behind

Recently I have been experimenting with WPF. I was building a little program, but then I stumbled across a little problem. I tried to call the Window_Closing method from the code behind, it told me that I needed to give it cerntain parameters, but I don't have those parameters in the method I am trying to call it from.
This is my code:
private void Window_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
// My Window Closing code
}
private void Application_Exit(object sender, RoutedEventArgs e)
{
// Here is where I am trying to call it, giving a empty parameter with it.
// But it doesn't seem to work.
Window_Closing(null, EventArgs.Empty)
}
What I want
If a cenrtain button is called, I want the Window_Closing event to be called.
Anyone who knows the solution?

In your Designer, click on the Button and open its property window. There you select the "Events" - the "lightning" and choose the Click event to execute your Window_Closing method. There is a drop down in which you should be able to select it. If not, enter your method name there and press "Enter" to let VS generate the code-behind method.

Add "Window_Closing" & "Close_Click" in the XAML file (MainWindow.xaml) as follows.
<Window x:Class="WpfApp1.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:WpfApp1"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800" Closing="Window_Closing">
<Grid>
<Button x:Name="Close" Content="Close" Click="Close_Click" Width="100" Height="30"/>
</Grid>
Then in the code behind file (MainWindow.xaml.cs) add the following code. Here the window close command is called from the button click event handler which in turn closes the window, and then the 'Window_Closing' event handler will be automatically called.
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void Window_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
}
private void Close_Click(object sender, RoutedEventArgs e)
{
Close();
}
}

Just close the window. Then the event will be called automatically, thats what it is there for to begin with.
And as it seems, you try calling it from your Application_Exit, which closes all the windows ... so .... What is your problem?
Just put a breakpoint in the Window_Closing and see, that is executed automatically. If not, maybe you should add the eventhander to all the windows Window_Closing events.

WPF Popup vs Tooltip

I have seen a lot of debate about when to use tooltip and when to use popup but I don't know which one is better for my case.
I have a button. When I click on it, the popup panel will appear and it has a lot of text and a small image (so it will be a quite big panel). The panel must stay there until I move my cursor OFF THE BUTTON (it must still close when the cursor is still on the panel but off the button).
<Button Click="clicked" MouseLeave="mouseleaved"/>
<Popup Name="mypopup">
<stuff>
</Popup>
private void clicked(object sender, RoutedEventArgs e) {
mypopopup.isopen = true;
}
private void mouseleaved(object sender, MouseEventArgs e) {
mypopup.isopen = false;
}
This is where I got to so far. The problem is that sometimes, the Popup appears on top of the button (which blocks the view of the button and so MouseLeave event kicks off, and Popup instantly disappears). I want the Popup to stay until i move the cursor away off the button.
So I did some google, and I think Tooltip may avoid this problem. But how to get Tooltip to appear on button click and not button hover?
Which one is better for me? Tooltip or Popup?
EDIT
I think I was not too clear with my question. I am asking which one i should use- Tooltip vs Popup based on MY SPECIFIC SITUATION (paragraph 2) and not in general. I think Popup is the right one to use but I have problems with using it (paragraph 3). so my question is can I solve this problem with Popup or should I use Tooltip better for this?

But how to get Tooltip to appear on button click and not button hover?
Handle the Click event for the Button and set the IsOpen property of the Popup to true:
private void Button_Click(object sender, RoutedEventArgs e)
{
popup1.IsOpen = true;
}
<Popup x:Name="popup1" StaysOpen="False">
<TextBlock>popup content...</TextBlock>
</Popup>
<Button Click="Button_Click" Content="op" />
Which one is better for me? Tooltip or Popup?
Popup is preferable whenever you want to customize the behaviour in any way.
Edit: If I understand your issue correctly, this should work:
<Button x:Name="button" Content="Button" Click="clicked" MouseLeave="mouseleaved"/>
<Popup Name="popup" PlacementTarget="{Binding ElementName=button}" StaysOpen="True" MouseLeave="mouseleaved">
<Border Background="Yellow">
<TextBlock>contents...</TextBlock>
</Border>
</Popup>
private void clicked(object sender, RoutedEventArgs e)
{
popup.IsOpen = true;
}
private void mouseleaved(object sender, MouseEventArgs e)
{
if (!button.IsMouseOver && !popup.IsMouseOver)
popup.IsOpen = false;
}

WPF Ribbon ApplicationMenu open and close event

I'm using the WPF Ribbon Application Menu:
https://www.microsoft.com/en-us/download/details.aspx?displaylang=en&id=11877
https://msdn.microsoft.com/de-de/library/ff799534(v=vs.110).aspx
How can I close the Application (File) Menu programmatically?
How can I detect if the user opens the Application Menu? I didn't found an appropriated event

You need IsDropDownOpen property and related event(s).
XAML (this is for .NET 4.5+, but for 4.0 it will be almost the same, the difference will be in namespace prefix):
<StackPanel>
<Ribbon>
<Ribbon.ApplicationMenu>
<RibbonApplicationMenu x:Name="Menu" DropDownOpened="RibbonApplicationMenu_DropDownOpened">
<RibbonApplicationMenuItem Header="Foo"/>
<RibbonApplicationMenuItem Header="Bar"/>
</RibbonApplicationMenu>
</Ribbon.ApplicationMenu>
</Ribbon>
</StackPanel>
Code-behind:
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void RibbonApplicationMenu_DropDownOpened(object sender, EventArgs e)
{
// user has opened menu
Debug.WriteLine("Menu opened.");
// let's close it from code
Menu.IsDropDownOpen = false;
}
}
Also, you may want to disable entire menu. This can be done using IsEnabled property.

Cannot drag text into a WPF window

I'm trying to set up a WPF window so that it can accept different types of data via Drag and Drop. If I make a new project and set the window to the following:
<Window x:Class="DropShare.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1" Height="300" Width="300" AllowDrop="True" DragEnter="Window_DragEnter">
<Grid>
</Grid>
</Window>
And set the code-behind to:
public partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
}
private void Window_DragEnter(object sender, DragEventArgs e)
{
}
}
I only ever get DragEnter firing for files. It never fires for anything else - text, images, etc.
Is there something I'm missing? All the tutorials I've read have seemed to suggest this is all that's needed as the DragEnter event handler let's me state what I accept.

So your code works fine for me. But try this...
In your Window:
<Label Background="Purple" HorizontalAlignment="Center" VerticalAlignment="Center" Content="Drag from here!" MouseDown="Label_MouseDown"/>
and in your code behind:
private void Label_MouseDown(object sender, MouseButtonEventArgs e)
{
DragDrop.DoDragDrop(this, "This is just a test", DragDropEffects.All);
}
Then drag from the label into the window and see if your event fires.
If this works, it may have something to do with the permissions level between Visual Studio and your outside environment (possibly).
See:
https://superuser.com/questions/59051/drag-and-drop-file-into-application-under-run-as-administrator

In WPF drag and drop feature always has to deal with DragDrop Class, Please check here how to do drag and drop across applications

Locking focus to a window WPF

I am adding a disclosure window to the start of my application. I want the window to be the only window that the user can interact with until it is closed. I have googled the heck out of it and have come up empty.
Thanks,
Joseph

You want modal dialog maybe? See ShowDialog() method.
For example:
App.xaml file:
<Application x:Class="WpfApplication3.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Startup="Application_Startup" />
App.xaml.cs file:
public partial class App : Application
{
private void Application_Startup(object sender, StartupEventArgs e)
{
var w = new YourDisclosureWindowClass();
w.ShowDialog();
// whatever you need to run you entire application
}
}