[C#] Hướng dẫn tạo hotkey cho ứng dụng winform

Bài viết hôm nay, mình sẽ hướng dẫn các bạn cách tạo Global Hotkey C#. Trong Visual Studio, các component của winform đều mặc định hỗ trợ thuộc tính hotkey cho chúng ta.

Nhưng nếu khi các bạn đang rê chuột nằm ngoài form ứng dụng, thì phải thực hiện thế nào?

Dưới dây là source code tạo Global Hotkey C#

using System;
using System.Windows.Forms;
 
namespace GlobalHotkeyExampleForm
{
    public partial class ExampleForm : Form
    {
        [System.Runtime.InteropServices.DllImport("user32.dll")]
        private static extern bool RegisterHotKey(IntPtr hWnd, int id, int fsModifiers, int vk);
        [System.Runtime.InteropServices.DllImport("user32.dll")]
        private static extern bool UnregisterHotKey(IntPtr hWnd, int id);
 
        enum KeyModifier
        {
            None = 0,
            Alt = 1,
            Control = 2,
            Shift = 4,
            WinKey = 8
        }
 
        public ExampleForm()
        {
            InitializeComponent();
 
            int id = 0;     // The id of the hotkey. 
            RegisterHotKey(this.Handle, id, (int)KeyModifier.Shift, Keys.A.GetHashCode());       // Register Shift + A as global hotkey. 
        }
 
        protected override void WndProc(ref Message m)
        {
            base.WndProc(ref m);
 
            if (m.Msg == 0x0312)
            {
                /* Note that the three lines below are not needed if you only want to register one hotkey.
                 * The below lines are useful in case you want to register multiple keys, which you can use a switch with the id as argument, or if you want to know which key/modifier was pressed for some particular reason. */
 
                Keys key = (Keys)(((int)m.LParam >> 16) & 0xFFFF);                  // The key of the hotkey that was pressed.
                KeyModifier modifier = (KeyModifier)((int)m.LParam & 0xFFFF);       // The modifier of the hotkey that was pressed.
                int id = m.WParam.ToInt32();                                        // The id of the hotkey that was pressed.
 
 
                MessageBox.Show("Hotkey has been pressed!");
                // do something
            }
        }
 
        private void ExampleForm_FormClosing(object sender, FormClosingEventArgs e)
        {
            UnregisterHotKey(this.Handle, 0);       // Unregister hotkey with id 0 before closing the form. You might want to call this more than once with different id values if you are planning to register more than one hotkey.
        }
    }
}

HAVE FUN :)