In WPF Controls, a beep sound is generated on Alt+Key keyboard combination.
I have some code which handle specific Alt+Key shortcuts in an override implementation of:
void UIElement.OnKeyDown(KeyEventArgs e);
Setting e.Handled = true doesn't mute the sound.
Neither does not calling base.OnKeyDown(e);
OnPreviewKeyDown behaves in the same way.
How to suppress this sound ?
WinForms apparently had e.SuppressKeyPress = true but that doesn't exist anymore in WPF.
to handle this you should use different event
private void TextBox_PreviewTextInput(object sender, TextCompositionEventArgs e)
{
e.Handled = true;
}
to know about this event ref :URL
Related
The focus rectangle and textbox caret are lost after disabling all controls, then enabling them again (vs2012 / .NET Framework v4.5).
To reproduce the issue, just create a WinForms application project, add a button and a textbox in the form, then use this code to disable and enable both controls in the button click event:
private void button1_Click(object sender, EventArgs e)
{
button1.Enabled = false;
textBox1.Enabled = false;
button1.Enabled = true;
textBox1.Enabled = true;
}
You may cycle between the textbox and the button using Tab/Shift+Tab as expected, until you press the button.
After that, the focus is partially lost (its weird). You can still use Tab/Shift+Tab and arrows to nagivate between the controls, and press Enter to active the button, but you cannot type in the textbox, nor use the space key to press the button. The textbox caret and the button focus rectangle are not displayed anymore. Changing focus to another application then returning to this form will fix the focus issue.
This issue does not happen if you don't disabled at least one control that is able to receive focus. Also the focus behavior is restored by disabling and enabling again the form, like this:
private void button1_Click(object sender, EventArgs e)
{
button1.Enabled = false;
textBox1.Enabled = false;
button1.Enabled = true;
textBox1.Enabled = true;
this.Enabled = false;
this.Enabled = true;
}
I was trying to disable all the controls of a more complex form at the start of a task, so the task would enable again all controls after finishing, to prevent user input during the processing, but without locking the UI thread. I thought it was related to the cross-thread invoke calls, but I found this issue happens even with all code running on UI thread.
This undesired behavior can be fixed by calling the form Focus() method:
private void button1_Click(object sender, EventArgs e)
{
button1.Enabled = false;
textBox1.Enabled = false;
button1.Enabled = true;
textBox1.Enabled = true;
this.Focus();
}
The ActiveControl is not changed after calling Focus(), so this works very well for me.
I have simple win form application with the tab and combo box controls.
Combo box control has a style of "Simple".
Tab control has key down event.
When I press Enter key on the combo control it fires TWO key down events. If you change the combo style to any other, the key down event fires only one which it is something I expect.
Has anybody got any ideas why I am getting two key down events for single enter key press?
I have found similar issue on the Microsoft website, but that was related to .NET 1.0.
http://support.microsoft.com/kb/814970
It has probably something to do with the Enter key having pre-defined behavior for the Simple DropDown style.
You can try this work-around in the KeyDown event:
void comboBox1_KeyDown(object sender, KeyEventArgs e) {
e.SuppressKeyPress = true;
// do stuff
}
As you can guess, the KeyPress event won't fire now.
If you need to still process things in the KeyPress event, you can try this work-around:
void comboBox1_KeyPress(object sender, KeyPressEventArgs e) {
if (e.KeyChar == (char)Keys.Enter) {
e.Handled = true;
} else {
// do stuff
}
}
KeyPress from Combobox accepts just 'char' keys. For you purpose, please, use KeyDown event for combobox and e.Handled property.
Then your code will work and look like:
private void comboBox2_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
comboBox2.KeyDown += new KeyEventHandler(comboBox2_SelectionChangeCommitted);
}
if (e.KeyCode != Keys.Enter)
{
e.Handled = false;
}
}
I have a window containing a textBox.
On both the window AND the textBox, I add a PreviewMouseDoubleClicHandler.
Handler in the window:
private void PreviewMouseDoubleClickHandler(object sender, MouseButtonEventArgs e)
{
Debug.WriteLine("handler in the window");
e.Handled = true;
}
handler in the textBox:
private void PreviewMouseDoubleClickHandler(object sender, MouseButtonEventArgs e)
{
Debug.WriteLine("handler in the textBox");
e.Handled = true;
}
now, when I double-click on the textBox, I expect to go first into the window's Handler, print the debug line, then handle the event, then nothing more. I thought the textBox's handler would not fire since the event has already been handled by the window.
This does not work like this though: I get both handlers fired.
The weird thing is: It works fine with the PreviewMouseDown event. If I do exactly the same thing but with PreviewMouseDownEvents, I get the behavior I expect, i.e.: the window handles the mouseDown and the textBox's handler is not fired.
so Why does this not work with the doubleClick event? Am I doing something wrong? Is it supposed to work like this? is the doubleClick Event managed in a different way that prevents me from using the advantages of tunneling?
The behavior is by design, please see: http://msdn.microsoft.com/en-us/library/system.windows.controls.control.previewmousedoubleclick.aspx
Snoop shows that the command is "ApplySingleSpace", but when I try disabling it via the method described in this article . Like this:
<RichTextBox.CommandBindings>
<CommandBinding
Command="ApplySingleSpace"
CanExecute="BlockTheCommand"/>
</RichTextBox.CommandBindings>
.
private void BlockTheCommand(object sender,
CanExecuteRoutedEventArgs e)
{
e.CanExecute = false;
e.Handled = true;
}
My app crashes because there is no ApplySingleSpace command. ApplySingleSpace is not in the EditingCommands either.
What am I missing?
Unfortunately that will not work for
me. The reason I am trying to disable
the command is that I have a
KeyBinding in a higher nested view
that is not firing because the CTRL+1
gesture is being swallowed by the
richtextbox which has keyboardfocus.
How about overwriting that KeyBinding with a custom command that does what you want instead of trying to somehow disable it?
<RichTextBox.InputBindings>
<KeyBinding Command="local:YourCommands.Cmd1" Gesture="CTRL+1" />
<RichTextBox.InputBindings>
Taken from this question.
Using the code from this answer
How can I programmatically generate keypress events in C#?
to refire all events on PreviewKeyDown other than those you want handled by the richtextbox seems to work for me. (I only need Ctrl-C for copy). Of course you could make it so it only refires Ctrl-1 if that's what you need.
private void logKeyHandler(object sender, KeyEventArgs e)
{
if (!(Keyboard.Modifiers == ModifierKeys.Control && e.Key == Key.C))
{
e.Handled = true;
var routedEvent = Keyboard.KeyDownEvent;
this.RaiseEvent(
new KeyEventArgs(
Keyboard.PrimaryDevice,
PresentationSource.FromDependencyObject(this),
0,
e.Key) { RoutedEvent = routedEvent }
);
}
}
What about trying with the gesture instead...
<RichTextBox.InputBindings>
<KeyBinding Command="BlockTheCommand" Gesture="CTRL+1" />
</RichTextBox.InputBindings>
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