The default behavior for the Slider.ValueChanged event is to trigger ValueChanged multiple times as the user drags the control. Is there a way to only trigger this event when the drag is over?
One thing I already tried was binding to the Thumb.DragStarted and Thumb.DragCompleted events, and adding some flags to control the process, but these events aren't fired if the user clicks in the body of the slider, outside the thumb.
If you don't want to customize the control you can handle the KeyUp event and the PointerCaptureLost events instead of handling the ValueChanged event.
private void slider_PointerCaptureLost(object sender, PointerRoutedEventArgs e)
{
HandleSliderValueChange();
}
private void slider_KeyUp(object sender, KeyRoutedEventArgs e)
{
//Make sure an arrow key, Home, or End was pressed
//either explicitly perform the flag checks
//if(e.Key.HasFlag(VirtualKey.Up & VirtualKey.Down & VirtualKey.Left & VirtualKey.Right & VirtualKey.Home & VirtualKey.End))
//or check the int values
int keyVal = (int)e.Key;
if(keyVal >= 35 && keyVal <= 40)
HandleSliderValueChange();
}
private void HandleSliderValueChange()
{
//your value changed code
}
This should call the HandleSliderValueChange method when the user finishes dragging, clicks on the slider itself, or uses the arrow, Home, or End keys to change the value.
Related
I have a pair of ComboBox controls having IsEditable() true as well as false.
When I am scrolling through my application or moving my application window (by clicking on the title bar) with list popup open, I would like to close the ComboBox list popup as otherwise there would be a weird delay in aligning the list correctly below the control.
Is this possible in UWP with WinRT/C++? If so, kindly suggest how to.
I did an investigation to find if any events are there to handle in such a scenario when ComboBox control is essentially displaced from initial position while moving the app window/scrolling the app, but couldn't find any help.
Edit: Adding ComboBox image from XAML Controls Gallery to demonstrate the behaviour. In case if IsEditable set as true, when popup is opened and application is scrolled then popup goes outside the window. Instead I would like to dismiss the popup itself. However, if IsEditable is set as false then we cannot scroll until the popup is dismissed.
Update: The code I tested for PointerWheelChanged
void CBFile2022X::OnPointerWheelChangedHandler( Windows::Foundation::IInspectable const& sender,
Windows::UI::Xaml::Input::PointerRoutedEventArgs const& eventargs )
{
OutputDebugString( L"PointerWheelChanged" );
if( ComboBox != nullptr )
{
ComboBox.IsEnabled( false );
ComboBox.IsEnabled( true );
}
}
I have to say that currently there is no event to detect if the application window is moved or changed its location.
Update:
You could handle the UIElement.PointerWheelChanged Event which will be fired when users scroll the mouse wheel. You could set the IsEnabled property of the ComboBox to false first and then set it to true, this will make the ComboBox lose its focus. Like:
private void Mypanel_PointerWheelChanged(object sender, PointerRoutedEventArgs e)
{
FontsCombo.IsEnabled = false;
FontsCombo.IsEnabled = true;
}
Update2:
If you are using a ScrollViewer you could try to handle the ScrollViewer.ViewChanging Event.
private void ScrollViewer_ViewChanging(object sender, ScrollViewerViewChangingEventArgs e)
{
FontsCombo.IsEnabled = false;
FontsCombo.IsEnabled = true;
}
Rather than making an event occur when a button is clicked once, I would like the event to occur only when the button is double-clicked. Sadly the double-click event doesn't appear in the list of Events in the IDE.
Anyone know a good solution to this problem? Thank you!
No the standard button does not react to double clicks. See the documentation for the Button.DoubleClick event. It doesn't react to double clicks because in Windows buttons always react to clicks and never to double clicks.
Do you hate your users? Because you'll be creating a button that acts differently than any other button in the system and some users will never figure that out.
That said you have to create a separate control derived from Button to event to this (because SetStyle is a protected method)
public class DoubleClickButton : Button
{
public DoubleClickButton()
{
SetStyle(ControlStyles.StandardClick | ControlStyles.StandardDoubleClick, true);
}
}
Then you'll have to add the DoubleClick event hanlder manually in your code since it still won't show up in the IDE:
public partial class Form1 : Form {
public Form1() {
InitializeComponent();
doubleClickButton1.DoubleClick += new EventHandler(doubleClickButton1_DoubleClick);
}
void doubleClickButton1_DoubleClick(object sender, EventArgs e) {
}
}
Use this. Code works.
public class DoubleClickButton : Button
{
public DoubleClickButton()
{
SetStyle(ControlStyles.StandardClick |
ControlStyles.StandardDoubleClick, true);
}
}
DoubleClickButton button = new DoubleClickButton();
button.DoubleClick += delegate (object sender, EventArgs e)
{
//codes
};
i used to add MouseDoubleClick event on my object like:
this.pictureBox.MouseDoubleClick += new System.Windows.Forms.MouseEventHandler(this.pictureBox_MouseDoubleClick);
A double click is simply two regular click events within a time t of each other.
Here is some pseudo code for that assuming t = 0.5 seconds
button.on('click' , function(event) {
if (timer is off or more than 0.5 milliseconds)
restart timer
if (timer is between 0 and 0.5 milliseconds)
execute double click handler
})
I am working on a Compact Framework application. This particular hardware implementation has a touchscreen, but its Soft Input Panel has buttons that are simply too small to be useful. There are more than one form where typed input is required, so I created a form with buttons laid out like a keypad. The forms that use this "keypad" form are modal dialogs. When a dialog requiring this "keypad" loads, I load the "keypad" form as modeless:
private void CardInputForm_Load(object sender, EventArgs e)
{
...
keypadForm = new KeypadForm();
keypadForm.Owner = this;
keypadForm.SetCallback(keyHandler);
keypadForm.Show();
}
The SetCallback method tells the "keypad" form where to send the keystrokes (as a Delegate).
The problem I'm having is that the modeless "keypad" form does not take input. It is displayed as I expect, but I get a beep when I press any of its buttons, and its caption is grayed-out. It seems like the modal dialog is blocking it.
I've read other posts on this forum that says modal dialogs can create & use modeless dialogs. Can anyone shed light on this situation? Is there a problem with my implementation?
I found the answer: Set the keypad form's Parent property, not its Owner property, to the form instance wanting the keystrokes. The keypad dialog's title bar stays grayed out, but the form is active.
private void CardInputForm_Load(object sender, EventArgs e)
{
// (do other work)
keypadForm = new KeypadForm();
keypadForm.Parent = this;
keypadForm.Top = 190; // set as appropriate
keypadForm.Show();
}
Be sure to clean up when done with the parent form. This can be in the parent's Closing or Closed events.
private void CardInputForm_Closing(object sender, CancelEventArgs e)
{
// (do other work)
keypadForm.Close();
keypadForm.Dispose();
}
There are two panels on the keypad form, one with numerals and one with letters and punctuation that I want. There is also an area not on a panel that is common to both, containing buttons for clear, backspace, enter/OK, and cancel. Each panel has a button to hide itself and unhide its counterpart ('ABC', '123', for example). I have all the buttons for input on the keypadForm fire a common event. All it does is send the button instance to the parent. The parent is responsible for determining what action or keystroke is desired. In my case I named the buttons "btnA", "btnB", "btn0", "btn1", "btnCancel", etc. For keystrokes, the parent form takes the last character of the name to determine what key is desired. This is a bit messy but it works. Any form wishing to use the keypad form inherits from a base class, defining a method for callback.
public partial class TimeClockBase : Form
{
public TimeClockBase()
{
InitializeComponent();
}
// (other implementation-specific base class functionality)
public virtual void KeyCallback(Button button)
{
}
}
The click event on the keypad form looks like this.
private void btnKey_Click(object sender, EventArgs e)
{
// play click sound if supported
(Parent as TimeClockBase).KeyCallback(sender as Button);
}
The method in the parent form looks like this.
public override void KeyCallback(Button button)
{
switch (button.Name)
{
case "btnCancel":
// setting result will cause form to close
DialogResult = DialogResult.Cancel;
break;
case "btnClear":
txtCardID.Text = string.Empty;
break;
// (handle other cases)
}
}
XAML C# not WEB page is a Window
At the click of a button I:
Need to trap the name of the last control OnFocus
Force the LostFocus event of the control.
// PROBLEM: clicking on btns does not force lostfocus event on the last entered element control (last entry control could be text,checkbox or others)
added save button, where calling such method it moves focus to parent forcing lostfocus on last element.
private void btnSave_Click(object sender, RoutedEventArgs e)
{
AcceptLastFocusedElement(sender, e);
}
private void AcceptLastFocusedElement(object sender, RoutedEventArgs e)
{
FocusManager.SetFocusedElement(this, (Button)sender);
}
NOTE: no need for task number 1 (getting the name of the element).
You could make use of the LayoutUpdated method.
So whenever there is any event happening, it goes into the LayoutUpdatedevent and you could trap the LastFocusObject .
I'm using gridview with templates to show and edit some information from a sql database.
When I edit and change the data in that row and then click enter it automatically presses the highest on page button which uses submit to server set to true which means it'll try to delete instead of update.
I've have tried setting a panel round the gridview and setting the panel's default button to the "updatebutton" but it won't allow that because it can't 'see' the buttons.
I had a similar problem and I found a very simple workaround:
Place a button below the GridView and make it invisible by CSS (i.e. position: relative; left: -2000px)
Create a Panel around the GridView and give it as DefaultButton the ID of the button we just created.
Write the following line of code for the click-event of the button:
myGridView.UpdateRow(myGridView.EditIndex, false);
Whenever you press enter in the GridView now, the edited row will be confirmed.
You need to precess KeyDown or KeyPress event of the grid, and check if pressed key if Keys.Enter :
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void dataGridView1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
button1_Click(this, EventArgs.Empty);
}
}
private void button1_Click(object sender, EventArgs e)
{
// Your logic here
}
}