Key Combination Event

Question

Upon request, I need to record the event of a combination of two-character keys and one control key (example (ALT + S + C). How can I implement the same thing.

Thanks Ranish

Answer 1

<interactivity:EventTrigger EventName="KeyDown"> <mvvmlight:EventToCommand Command="{Binding Command}" PassEventArgsToCommand="True" /> </interactivity:EventTrigger> private void Event() { if ((Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control) { if (Keyboard.IsKeyDown(Key.C) && Keyboard.IsKeyDown(Key.T)) { //code } } } 

Answer 2

EDIT: Changed code. Using the Gesture and Key properties is not possible. The last property declared will be used as the key, and the key specified in the Gesture property will be ignored.

The following code is possible with only 2 modifiers, and not with two keys:

 <KeyBinding Gesture="Alt+Shift+C" Command="{Binding ACommand}"/> 

To implement key combinations with 2 keys and one ModifierKey following article looks very useful:

KeyGesture with multiple keys

Answer 3

Using the KeyDown :

 if ((Keyboard.Modifiers & ModifierKeys.Alt) == ModifierKeys.Alt) // Is Alt key pressed { if (Keyboard.IsKeyDown(Key.S) && Keyboard.IsKeyDown(Key.C)) { // do something here } } 

Answer 4

If you want to associate an action with this combination, than you do it,

 <KeyBinding Gesture="Alt+S+C" Command="{Binding YourCommand}" /> 

See the msdn link

Answer 5

You can determine, using the code below,

  private void UIElement_OnPreviewKeyDown(object sender, KeyEventArgs e) { if (Keyboard.Modifiers == ModifierKeys.Alt && Keyboard.IsKeyDown(Key.S) && Keyboard.IsKeyDown(Key.C)) { //if you want, you can fire event here } } 

Answer 6

If the intention is to allow users to enter a sequence of characters with controls such as comment / uncomment macros in visual studio, then you can do something like this (this is very rude, just give you an idea of ​​how this will work)

Add a custom control that looks for keystrokes on it, and also contains a set of gestures to view.

 using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows; using System.Windows.Controls; using System.Windows.Input; using System.Windows.Markup; namespace WpfApplication4 { [ContentProperty("Gestures")] public class KeyGestures : Control { public List<IKeyGesture> Gestures { get { return (List<IKeyGesture>)GetValue(GesturesProperty); } set { SetValue(GesturesProperty, value); } } public static readonly DependencyProperty GesturesProperty = DependencyProperty.Register("Gestures", typeof(List<IKeyGesture>), typeof(KeyGestures), new PropertyMetadata(null)); public List<string> CurrentSequence { get { return (List<string>)GetValue(CurrentSequenceProperty); } set { SetValue(CurrentSequenceProperty, value); } } public static readonly DependencyProperty CurrentSequenceProperty = DependencyProperty.Register("CurrentSequence", typeof(List<string>), typeof(KeyGestures), new PropertyMetadata(null)); public KeyGestures() { Gestures = new List<IKeyGesture>(); CurrentSequence = new List<string>(); } protected override void OnInitialized(EventArgs e) { var hostWindow = Window.GetWindow(this); if (hostWindow != null) { hostWindow.PreviewKeyDown += hostWinow_PreviewKeyDown; hostWindow.PreviewKeyUp += hostWinow_PreviewKeyUp; } base.OnInitialized(e); } bool IsAnyKeyPressed() { var allPossibleKeys = Enum.GetValues(typeof(Key)); bool results = false; foreach (var currentKey in allPossibleKeys) { Key key = (Key)currentKey; if (key != Key.None) if (Keyboard.IsKeyDown((Key)currentKey)) { results = true; break; } } return results; } void hostWinow_PreviewKeyUp(object sender, System.Windows.Input.KeyEventArgs e) { if (!IsAnyKeyPressed()) { CurrentSequence.Clear(); } } void hostWinow_PreviewKeyDown(object sender, System.Windows.Input.KeyEventArgs e) { if (e.SystemKey == Key.None) { if (!CurrentSequence.Contains(e.Key.ToString())) CurrentSequence.Add(e.Key.ToString()); } else if (!CurrentSequence.Contains(e.SystemKey.ToString())) CurrentSequence.Add(e.SystemKey.ToString()); foreach (var gesture in Gestures) if (gesture.IsComplete(this.CurrentSequence)) { if (gesture.Command != null && gesture.Command.CanExecute(gesture.CommandParameter)) gesture.Command.Execute(gesture.CommandParameter); System.Diagnostics.Debug.WriteLine("Completed gesture " + gesture); } } } public interface IKeyGesture { bool IsComplete(List<string> currentSequence); ICommand Command { get; } object CommandParameter { get; set; } } public class SequenceKeyGesture : DependencyObject, IKeyGesture { public string Sequence { get; set; } public char SplitChar { get; set; } public ICommand Command { get; set; } public object CommandParameter { get { return (object)GetValue(CommandParameterProperty); } set { SetValue(CommandParameterProperty, value); } } public static readonly DependencyProperty CommandParameterProperty = DependencyProperty.Register("CommandParameter", typeof(object), typeof(SequenceKeyGesture), new PropertyMetadata(null)); public bool IsComplete(List<string> currentSequence) { string[] splitSequence = Sequence.Split(SplitChar); if (splitSequence.Length != currentSequence.Count) return false; if (splitSequence != null && splitSequence.Length > 0) for (int i = 0; i < splitSequence.Length; i++) if (splitSequence[i] != currentSequence[i]) return false; return true; } public SequenceKeyGesture() { SplitChar = '+'; } public override string ToString() { return Sequence; } } } 

Then it can be used with the following xaml

 <Window x:Class="WpfApplication4.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:WpfApplication4" Title="MainWindow" Height="350" Width="525"> <Grid> <local:KeyGestures> <local:SequenceKeyGesture Sequence="LeftAlt~S~C" SplitChar="~" Command="{Command binding here}" CommandParameter="Action1" /> <local:SequenceKeyGesture Sequence="LeftAlt+S+V" Command="{Command binding here" CommandParameter="Action2"/> </local:KeyGestures> </Grid> </Window> 

There is Debug.WriteLine to show you when the gesture starts, if you want to test without setting up commands.