Capture a keyup event at application level in WPF - wpf

Hi I have an application built in wpf.
At the base level I have a usercontrol and on that usercontrol are many components.
I want to be able to capture a key press event on my usercontrol even if the focus is on one of the children. Using PreviewKeyUp doesn't seem to do the trick.
Thanks,
Matt.

Maybe I understood your question not fully, but if you don't set the keydown event to handled, it should go up the hierarchy.
public UserControl1()
{
InitializeComponent();
this.KeyDown += new KeyEventHandler(UserControl1_KeyDown);
textBox1.KeyDown += new KeyEventHandler(textBox1_KeyDown);
}
void textBox1_KeyDown(object sender, KeyEventArgs e)
{
Console.WriteLine("txt keydown: "+e.Key.ToString());
}
void UserControl1_KeyDown(object sender, KeyEventArgs e)
{
Console.WriteLine(e.Key.ToString());
}
output:
txt keydown: Y
Y

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How to know whether a control such as TextBox has the input focus in a Windows Phone Silverlight app?
You have to use FocusManager
bool b = FocusManager.GetFocusedElement() == myTextbox;
There are events like GotFocus and LostFocus for controls.
If you subscribe to these events they automatically get called when your input receives or looses focus
you can use those events for your purpose.
XAML Declaration
<TextBox Name="myTextbox" GotFocus="myTextbox_GotFocus" />
and inside the cs
private void myTextbox_GotFocus(object sender, RoutedEventArgs e)
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}
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ManipulationStarted fails to activate callback method

I have a WPF Canvas with .NET-4.5.
I added events (which autocreated methods for) MouseLeftButtonDown and MouseDown. Using MessageBox, I have confirmed these methods are called when a user clicks on the canvas, but I can't find a way to get the mouse position from MouseButtonEventArgs.
When I added events (and autocreated methods for) ManipulationStarted and ManipulationStarting those MessageBoxes don't show up.
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MessageBox.Show("Shows up"); // shows up, but can't seem to get click position
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In order to get the mouse position from a MouseEventArgs you would have to call the GetPosition method.
private void Canvas_MouseDown(object sender, MouseButtonEventArgs e)
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It is possible to create "new MouseButtonEventArgs" in Silverlight?

I'm newbie in Silverlight and I need to activate MouseRightButtonDown(object sender, MouseButtonEventArgs e) from an another event handler in my application.
I have found, that in WPF it is possible to do somthing like this:
public void OnContextMenuOpened(object sender, RoutedEventArgs e) {
MouseButtonEventArgs args = new MouseButtonEventArgs(
InputManager.Current.PrimaryMouseDevice,
0,
MouseButton.Right);
MouseRightButtonDown(sender, args);
}
But I have in Silverlight neither InputManager-Class nor MouseButton-Class... It is generally possible to realise something like that?
I want to do it, because I try to select an DataGridRow(within an custom control) with help of right-mouse-button. Without context menu it is easily possible, but when I switch context menu on, then context menu opens and event will not fired...
My code snippet:
public override void OnApplyTemplate() {
DataGrid = (DataGrid)GetTemplateChild("DataGrid");
DataGrid.MouseRightButtonDown += DataGridMouseRightButtonDown;
ContextMenu = (ContextMenu)GetTemplateChild("ContextMenu");
ContextMenu.Opened += OnContextMenuOpened;
}
private void DataGridMouseRightButtonDown(object sender, MouseButtonEventArgs e) {
//My code to select an DataGridRow
}
public void OnContextMenuOpened(object sender, RoutedEventArgs e) {
//This event-handler now will be always activated if I do
//right-mouse-button-click
}
Thanks a lot for help!
The Results of my research has shown, that it is impossible in silverlight -.-

What event can I change the caret in in a winforms maskedtextbox

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Unfortunately the enter event or even the invalidate event aren't suitable places to change that caret. It doesn't change, maybe because they fire too early.
So anyway, how can I get the caret to change on textbox enter without handling it in the enter event?
You need to add DestroyCaret to your routine, too:
private void Form1_Load(object sender, EventArgs e)
{
textBox1.GotFocus += new EventHandler(textBox1_GotFocus);
textBox1.LostFocus += new EventHandler(textBox1_LostFocus);
}
private void textBox1_GotFocus(object sender, EventArgs e)
{
CreateCaret(textBox1.Handle, IntPtr.Zero, 6, textBox1.Height);
ShowCaret(textBox1.Handle);
}
private void textBox1_LostFocus(object sender, EventArgs e)
{
DestroyCaret();
}

WPF Mousedown => No MouseLeave Event

I'm building a Windows Presentation Foundation control with Microsoft Blend.
When I leave my control by pressing the left-mouse-button, the MouseLeave-Event is not raised. Why not?
This is intended behaviour: When you are doing mousedown on a control and leaving the control, the control STILL retains its "capture" on the mouse, meaning the control won't fire the MouseLeave-Event. The Mouse-Leave Event instead will be fired, once the Mousebutton is released outside of the control.
To avoid this, you can simple tell your control NOT to capture the mouse at all:
private void ControlMouseDown(System.Object sender, System.Windows.Forms.MouseEventArgs e)
{
Control control = (Control) sender;
control.Capture = false; //release capture.
}
Now the MouseLeave Event will be fired even when moving out while a button is pressed.
If you need the Capture INSIDE the Control, you need to put in more effort:
Start tracking the mouseposition manually, when the mousekey is pressed
Compare the position with the Top, Left and Size Attributes of the control in question.
Decide whether you need to stop the control capturing your mouse or not.
public partial class Form1 : Form
{
private Point point;
private Boolean myCapture = false;
public Form1()
{
InitializeComponent();
}
private void button1_MouseDown(object sender, MouseEventArgs e)
{
myCapture = true;
}
private void button1_MouseMove(object sender, MouseEventArgs e)
{
if (myCapture)
{
point = Cursor.Position;
if (!(point.X > button1.Left && point.X < button1.Left + button1.Size.Width && point.Y > button1.Top && point.Y < button1.Top + button1.Size.Height))
{
button1.Capture = false; //this will release the capture and trigger the MouseLeave event immediately.
myCapture = false;
}
}
}
private void button1_MouseLeave(object sender, EventArgs e)
{
MessageBox.Show("Mouse leaving");
}
}
of course you need to stop the own tracking ( myCapture=false;) on MouseUp. Forgot that one :)
When I don't get mouse events I expect I typically use Snoop to help me understand what is happening.
Here are a couple of links:
1- Snoop (a WPF utility)
2- CodePlex project for Snoop
And for completeness and historical reasons (not the bounty - it doesn't make sense having two duplicate questions - you should probably move it into one if not too late)...
I made a thorough solution using global mouse hook here (approach 2)
WPF: mouse leave event doesn't trigger with mouse down
And simplified its use - you can use it by binding to commands in your view-model - e.g.
my:Hooks.EnterCommand="{Binding EnterCommand}"
my:Hooks.LeaveCommand="{Binding LeaveCommand}"
my:Hooks.MouseMoveCommand="{Binding MoveCommand}"
...more details in there
Old question but I came across the same problem with a Button (MouseLeave does not fire while MouseDown because MouseDown Captures the Mouse...)
This is how I solved it anyway:
element.GotMouseCapture += element_MouseCaptured;
static void element_MouseCaptured(object sender, MouseEventArgs e)
{
FrameworkElement element = (FrameworkElement)sender;
element.ReleaseMouseCapture();
}
Hope that helps someone looking for a quick fix :P

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