ScreenCaptureApp/MainForm.cs

using System;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace ScreenCaptureApp
{
    public partial class MainForm : Form
    {
        [DllImport("user32.dll")]
        private static extern bool RegisterHotKey(IntPtr hWnd, int id, int fsModifiers, int vk);

        [DllImport("user32.dll")]
        private static extern bool UnregisterHotKey(IntPtr hWnd, int id);

        private const int WM_HOTKEY = 0x0312;
        private const int PRINT_SCREEN_ID = 1;
        private bool captureOnKeyPress = true;

        public MainForm()
        {
            InitializeComponent();
            RegisterHotkey();
            this.Hide(); // Сразу скрываем основное окно
        }

        private void ShowMainWindow()
        {
            if (this.WindowState == FormWindowState.Minimized)
            {
                this.WindowState = FormWindowState.Normal;
            }
            this.Show();
            this.Activate();
        }

        private void RegisterHotkey()
        {
            // Регистрируем Print Screen (0x2C) без модификаторов (0x0)
            if (!RegisterHotKey(this.Handle, PRINT_SCREEN_ID, 0x0, 0x2C))
            {
                MessageBox.Show("Failed to register Print Screen hotkey", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }

        private void ExitApplication()
        {
            UnregisterHotKey(this.Handle, PRINT_SCREEN_ID);
            notifyIcon1.Visible = false;
            Application.Exit();
        }

        protected override void WndProc(ref Message m)
        {
            if (m.Msg == WM_HOTKEY && captureOnKeyPress)
            {
                if (m.WParam.ToInt32() == PRINT_SCREEN_ID)
                {
                    CaptureScreen();
                }
            }
            base.WndProc(ref m);
        }

        private void CaptureScreen()
        {
            this.Hide();
            using (var captureForm = new ScreenCaptureForm())
            {
                if (captureForm.ShowDialog() == DialogResult.OK)
                {
                    ProcessCapturedImage(captureForm.CapturedImage);
                }
            }
            this.Show();
        }

        private void ProcessCapturedImage(Image image)
        {
            using (var resultForm = new ResultForm(image))
            {
                var result = resultForm.ShowDialog();
                if (result == DialogResult.OK)
                {
                    SaveImage(image);
                }
                else if (result == DialogResult.Yes)
                {
                    CopyToClipboard(image);
                }
            }
        }

        private void SaveImage(Image image)
        {
            using (var sfd = new SaveFileDialog())
            {
                sfd.Filter = "PNG Image|*.png|JPEG Image|*.jpg|Bitmap Image|*.bmp";
                if (sfd.ShowDialog() == DialogResult.OK)
                {
                    image.Save(sfd.FileName, GetImageFormat(sfd.FileName));
                    notifyIcon1.ShowBalloonTip(1000, "Success", "Screenshot saved!", ToolTipIcon.Info);
                }
            }
        }

        private void CopyToClipboard(Image image)
        {
            try
            {
                Clipboard.SetImage(image);
                notifyIcon1.ShowBalloonTip(1000, "Success", "Copied to clipboard!", ToolTipIcon.Info);
            }
            catch (Exception ex)
            {
                notifyIcon1.ShowBalloonTip(1000, "Error", $"Copy failed: {ex.Message}", ToolTipIcon.Error);
            }
        }

        private System.Drawing.Imaging.ImageFormat GetImageFormat(string fileName)
        {
            string ext = System.IO.Path.GetExtension(fileName).ToLower();
            switch (ext)
            {
                case ".jpg": return System.Drawing.Imaging.ImageFormat.Jpeg;
                case ".jpeg": return System.Drawing.Imaging.ImageFormat.Jpeg;
                case ".bmp": return System.Drawing.Imaging.ImageFormat.Bmp;
                default: return System.Drawing.Imaging.ImageFormat.Png;
            }
        }

        private void notifyIcon1_MouseClick(object sender, EventArgs e) => ShowMainWindow();

        private void showToolStripMenuItem_Click(object sender, EventArgs e) => ShowMainWindow();

        private void toggleHotkeyToolStripMenuItem_Click(object sender, EventArgs e)
        {
            captureOnKeyPress = !captureOnKeyPress;
            var item = (ToolStripMenuItem)sender;
            item.Text = $"Print Screen Capture: {(captureOnKeyPress ? "ON" : "OFF")}";
            notifyIcon1.ShowBalloonTip(1000, "Hotkey",
                $"Print Screen capture {(captureOnKeyPress ? "enabled" : "disabled")}",
                ToolTipIcon.Info);
        }

        private void exitToolStripMenuItem_Click(Object sender, EventArgs e)
        {
            ExitApplication();
        }

        protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);
            this.Hide(); // Гарантированно скрываем окно при загрузке
        }

        protected override void OnFormClosing(FormClosingEventArgs e)
        {
            base.OnFormClosing(e);
            ExitApplication();
        }
    }
}