WinForm制作相对美观的登录窗体

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

namespace WinFormLoginUI
{
    /// <summary>
    ///     WinForm制作相对美观的登录窗体
    ///     LDH @ 2021-3-22
    /// </summary>
    public partial class FrmLogin : Form
    {
        public const int WM_SYSCOMMAND = 0x0112;
        public const int SC_MOVE = 0xF010;
        public const int HTCAPTION = 0x0002;


        public FrmLogin()
        {
            InitializeComponent();
        }

        [DllImport("user32.dll")]
        public static extern bool ReleaseCapture();

        [DllImport("user32.dll")]
        public static extern bool SendMessage(IntPtr hwnd, int wMsg, int wParam, int lParam);

        /// <summary>
        ///     窗体的MouseDown事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void FrmMain_MouseDown(object sender, MouseEventArgs e)
        {
            ReleaseCapture();
            SendMessage(Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0);
        }

        private void picExit_Click(object sender, EventArgs e)
        {
            Environment.Exit(0);
        }

        private void picMinimum_Click(object sender, EventArgs e)
        {
            WindowState = FormWindowState.Minimized;
        }

        private void FrmLogin_Load(object sender, EventArgs e)
        {
            SetWatermarks();
            MouseDown += FrmMain_MouseDown;
        }

        /// <summary>
        ///     Set Watermarks
        /// </summary>
        private void SetWatermarks()
        {
            txtAccount.SetWatermark("Please input your account.");
            txtPwd.SetWatermark("Please input your password.");
        }

        private void MyMouseMove(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                ReleaseCapture();
                SendMessage(Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0);
            }
        }

        private void btnReset_Click(object sender, EventArgs e)
        {
            txtAccount.ResetAndFocus();
            txtPwd.Clear();
        }
    }
}