I have a UserControl in my WPF application.
I want to call a click event and do some things when the user clicked the UserControl.
The problem is- the UserControl doesn't have a click event.
I searched on the web and found that you can use the MouseLeftButtonUp event.
I tried it- but it doesn't respond to my clicks.
You didn't write what you are trying to do but if you need a click event maybe you are writing some kind of button (the Button class is actually "something you can click" with the visual representation in a control template you can replace)
If you need a button with complex content inside - put your user control inside a button
If you need a button that doesn't look like a button write a custom control template for button
If you need a button with extra functionality subclass button, add the extra data/behavior in code and put the display XAML in a style.
I think for your needs PreviewMouseLeftButtonUp(Down) event is more suitable. Then you need to handle ClickCount for counting amount of clicks and then raise your own event, on which other controls will know, that your control is clicked. There are much more methods on handling click event. You should look at this msdn article and this
UPDATE to handle both Click and DoubleClick
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
_myCustomUserControl.MouseLeftButtonUp += new MouseButtonEventHandler(_myCustomUserControl_MouseLeftButtonUp);
_myCustomUserControl.MouseDoubleClick += new MouseButtonEventHandler(_myCustomUserControl_MouseDoubleClick);
}
bool _doubleClicked;
void _myCustomUserControl_MouseDoubleClick(object sender, MouseButtonEventArgs e)
{
_textBlock.Text = "Mouse left button clicked twice";
_doubleClicked = true;
e.Handled = true;
}
void _myCustomUserControl_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
if (_doubleClicked)
{
_doubleClicked = false;
return;
}
_textBlock.Text = "Mouse left button clicked once";
e.Handled = true;
}
}
To test this example name your control as _myCustomUserControl and add a TextBlock named _textBlock to your MainWindow.xaml
Why not just use MouseDown?
Put the event in the User Control and simply do this:
private void MyControl_MouseDown(object sender, MouseButtonEventArgs e)
{
if (e.ChangedButton == MouseButton.Left)
{
MessageBox.Show("Clicked!");
}
}
Related
I have am making a map editor for a game which has a user control that has an image. Inside that control I attached the MouseWheel event to it, but I've noticed two issues that I hope to have a better understanding of why it behaves the way it does and how to properly implement it.
For one the event only seems to fire when the mouse is hovering over it instead of when the control is in focus. If possible I would like to switch that and be able to fire the event no matter where the mouse is as long as that control is in focus and the second issue is that checking the delta when the number is positive works fine, but when I get a number back when it's negative I get a value of 0xfffffffd or something in that range. How would I go about differentiating the difference between a positive balue and a negative value if I always get something positive?
Thanks in advance for the help.
If you want to fire MouseWheel event for focused element try:
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
this.MouseWheel += OnMouseWheel;
}
IInputElement focusedElement;
private void OnMouseWheel(object sender, MouseWheelEventArgs e)
{
if (focusedElement is TextBox)
{
var tbx = focusedElement as TextBox;
//do something
}
}
protected override void OnPreviewLostKeyboardFocus(KeyboardFocusChangedEventArgs e)
{
focusedElement = e.NewFocus;
}
}
I have a ListBox that is bound to a list of items. The ListBoxItem is bound to a datatemplate of type Button.
On the click of button, I do some action (another window is shown). So i have bound to the Command of the button.
Now my requirement is that i show a POPUP (with some buttons in popup) to the right click of the button.
How would i be able to do this in MVVM ?
Girija
You can simply catch MouseUp event from ListBox.ItemTemplate and set Popup.IsOpen there:
private void SomeTemplateElement_MouseUp(object sender, MouseButtonEventArgs e)
{
if (e.ChangedButton == MouseButton.Right)
puMyPopup.IsOpen = true;
}
Popup is a view element, so I don`t think there`s a reason to open it through viewmodel commands.
I creating a custonmized box class (inherits from ComboBox). I don't want the text box to react to right mouse clicks. I can get rid of the context menu by setting this to null in ApplyTemplate, but right mouse clicks move the cursor. I tried hooking up PreviewMouseRightButtonDown in ApplyTemplate and setting Handled to True, but the event still gets through which is strange as it seems to work for the left click.
The cursor actually moves when the mouse button is released, so you want mark the MouseRightButtonUp event as handled. You could override OnMouseRightButtonUp:
protected override void OnMouseRightButtonUp(MouseButtonEventArgs e)
{
base.OnMouseRightButtonUp(e);
e.Handled = true;
}
Or you could attach a class handler to the MouseRightButtonUp event to mark it as handled:
static MyComboBox()
{
EventManager.RegisterClassHandler(
typeof(MyComboBox),
MouseRightButtonUpEvent,
new MouseButtonEventHandler(MyComboBox_MouseRightButtonUp));
}
private static void MyComboBox_MouseRightButtonUp(
object sender, MouseButtonEventArgs e)
{
e.Handled = true;
}
That will also prevent the context menu from being created without you having to set it to null explicitly.
I have a button inside my UserControl. I have three instances of this UserControl on the same page.
How can I expose the click event of the button inside such that I can assign different events for each instance of my UserControl.
I think this is similar to concept behind exposing DependencyProperty but I don't understand how to do it for events.
Thanks.
I normally add an event of the same name (and same parameters) to the user control and subscribe to the child control's original event, so I can pass the event on:
public partial class ClickEventControl : UserControl
{
public event EventHandler<RoutedEventArgs> Click;
public ClickEventControl()
{
InitializeComponent();
}
private void aButton_Click(object sender, RoutedEventArgs e)
{
if (Click != null)
{
Click(sender, e);
}
}
}
I would also be interested if there is a more general way of doing it.
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