Best Way to Implement Keyboard Shortcuts in a Windows Forms Application

Best way to implement keyboard shortcuts in a Windows Forms application?

You probably forgot to set the form's KeyPreview property to True. Overriding the ProcessCmdKey() method is the generic solution:

protected override bool ProcessCmdKey(ref Message msg, Keys keyData) {
  if (keyData == (Keys.Control | Keys.F)) {
    MessageBox.Show("What the Ctrl+F?");
    return true;
  }
  return base.ProcessCmdKey(ref msg, keyData);
}

How to set hotkeys for a Windows Forms form

Set

myForm.KeyPreview = true;

Create a handler for the KeyDown event:

myForm.KeyDown += new KeyEventHandler(Form_KeyDown);

Example of handler:

    // Hot keys handler
    void Form_KeyDown(object sender, KeyEventArgs e)
    {
        if (e.Control && e.KeyCode == Keys.S)       // Ctrl-S Save
        {
            // Do what you want here
            e.SuppressKeyPress = true;  // Stops other controls on the form receiving event.
        }
    }

How to assign a shortcut key (something like Ctrl+F) to a text box in Windows Forms?

Capture the KeyDown event and place an if statement in it to check what keys were pressed.

private void form_KeyDown(object sender, KeyEventArgs e)
{
    if ((e.Control && e.KeyCode == Keys.F) || (e.Control && e.KeyCode == Keys.S)) {
        txtSearch.Focus();
    }
}

How do I create compound keyboard shortcuts in a Windows Forms application?

In answer to the question of keyboard chords specifically, I do not believe there is a ready-made option available to you at this point.

However, it should be simple enough to model. I would create a single class, perhaps KeyboardChordProvider. It will need to know about keyboard events at the form level. As stated elsewhere, the Form.KeyPreview property must be true. It may be enough for this provider to subscribe to the Form.KeyPress event. You could do all of this in the provider's constructor if you passed in the form.

You would need to register the potential keystrokes with the provider.

Internally this instance will track the current state. Whenever a keystroke is observed that represents the first key of the chord, you would update the provider's state and raise an event so that a subscriber could set text: (CTRL+W) was pressed. Waiting for second key of chord...

If the next keystroke matches a potential secondary option, then you have a match and could raise a ChordPressed event containing the details of the strokes entered. Alternatively, you might just call a particular callback that was given to the provider at the time the chord was registered (to avoid having a switch statement or some other dispatch in the ChordPressed event handler).

If, at any time, a keystroke does not match a potential next option, then you would reset the state of the provider.

Internal to the provider you might model the possible keystrokes using a tree structure. The current state of the provider is just a particular tree node. At the beginning, the root node would be active. If a child matches a keystroke then it becomes the current node in anticipation of the next stroke. If the child was a leaf node, then an entire chord has matched and you would raise ChordPressed event (passing the chain of strokes that got you to that point) or invoke the callback stored in the leaf. Whenever no keystroke matches a child, reset back to making the root node active.

I think this design would achieve what you want.

How can you create Alt shortcuts in a Windows Forms application?

When the label receives focus from pressing its accelerator key (set using the &), it forwards the focus to the next control in the tab order, since labels are not editable. You need the textbox to be next control in the tab order.

To view and correct the tab order of your form, use the View + Tab Order command in the IDE. Using TabPages or other containers adds a level of nesting to the tab order (e.g., 1.1, 1.2 instead of just 1 and 2), but if the label and textbox are within the same container it shouldn't be too hard to set properly.

Implement Custom Shortcut keys in winforms dynamically

Use the Shortcut Property on the SharedProps of the tool that you want the shortcut for.

Note that you are limited to Shortcut key combinations in the Shortcut Enumeration.

Maximize C# Application from System Tray using Keyboard Shortcut

EDIT: If you simply want to 'reserve a key combination' to perform something on your application, a Low-Level keyboard hook whereby you see every keypress going to any other application is not only an overkill, but bad practice and in my personal view likely to have people thinking that you're keylogging! Stick to a HOT-KEY!

Given that your icon will not have keyboard focus, you need to register a global keyboard hotkey.

Other similar questions:

• How can I register a global hot key to say CTRL+SHIFT+(LETTER)
• Best way to tackle global hotkey processing in c#?

Example from Global Hotkeys With .NET:

Hotkey hk = new Hotkey();
hk.KeyCode = Keys.1;
hk.Windows = true;
hk.Pressed += delegate { Console.WriteLine("Windows+1 pressed!"); };

if (!hk.GetCanRegister(myForm))
{ 
    Console.WriteLine("Whoops, looks like attempts to register will fail " +
                      "or throw an exception, show error to user"); 
}
else
{ 
    hk.Register(myForm); 
}

// .. later, at some point
if (hk.Registered)
{ 
   hk.Unregister(); 
}

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