C# Winform DateTimePicker 字型/視窗 大小 控制設定 [建立自定義UI元件]

資料來源:

https://stackoverflow.com/questions/48020286/is-it-possible-to-increase-size-of-calendar-popup-in-winform
https://blog.csdn.net/QinYHJ/article/details/124841156

https://rjcodeadvance.com/custom-datetimepicker-custom-controls-winform-c/

https://www.youtube.com/watch?v=IJM9SIX0pIs

code01:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Runtime.InteropServices;//C# 呼叫 DLL API

namespace CS_VPOS
{
    //https://stackoverflow.com/questions/48020286/is-it-possible-to-increase-size-of-calendar-popup-in-winform
    //https://blog.csdn.net/QinYHJ/article/details/124841156
    
    public class MyDateTimePicker : DateTimePicker
    {
        private const int SWP_NOMOVE = 0x0002;
        private const int DTM_First = 0x1000;
        private const int DTM_GETMONTHCAL = DTM_First + 8;
        private const int MCM_GETMINREQRECT = DTM_First + 9;

        [DllImport("uxtheme.dll")]
        private static extern int SetWindowTheme(IntPtr hWnd, string appName, string idList);
        [DllImport("user32.dll")]
        static extern IntPtr SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);
        [DllImport("user32.dll")]
        static extern IntPtr SendMessage(IntPtr hWnd, int Msg, int wParam, ref RECT lParam);
        [DllImport("user32.dll")]
        static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter,
        int X, int Y, int cx, int cy, int uFlags);
        [DllImport("User32.dll")]
        private static extern IntPtr GetParent(IntPtr hWnd);
        [StructLayout(LayoutKind.Sequential)]
        private struct RECT { public int L, T, R, B; }
        protected override void OnDropDown(EventArgs eventargs)
        {
            //添加后编译程序，在要使用的界面拖动用户控件使用即可，弹出窗口的大小会根据CalendarFont决定
            var hwndCalendar = SendMessage(this.Handle, DTM_GETMONTHCAL, 0, 0);
            SetWindowTheme(hwndCalendar, string.Empty, string.Empty);
            var r = new RECT();
            SendMessage(hwndCalendar, MCM_GETMINREQRECT, 0, ref r);
            var hwndDropDown = GetParent(hwndCalendar);
            SetWindowPos(hwndDropDown, IntPtr.Zero, 0, 0,
                r.R - r.L + 6, r.B - r.T + 6, SWP_NOMOVE);
            base.OnDropDown(eventargs);
        }
    }
}

code02:

using System;
using System.Collections.Generic;
using System.Drawing.Drawing2D;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Runtime.InteropServices;

//https://rjcodeadvance.com/custom-datetimepicker-custom-controls-winform-c/
//https://www.youtube.com/watch?v=IJM9SIX0pIs

//https://stackoverflow.com/questions/48020286/is-it-possible-to-increase-size-of-calendar-popup-in-winform
//https://blog.csdn.net/QinYHJ/article/details/124841156

namespace CS_VPOS
{
    public class RJDatePicker : DateTimePicker
    {
        //Fields
        //-> Appearance
        private Color skinColor = Color.MediumSlateBlue;
        private Color textColor = Color.White;
        private Color borderColor = Color.PaleVioletRed;
        private int borderSize = 0;

        //-> Other Values
        private bool droppedDown = false;
        private Image calendarIcon = Properties.Resources.calendarWhite;
        private RectangleF iconButtonArea;
        private const int calendarIconWidth = 34;
        private const int arrowIconWidth = 17;

        //Properties
        public Color SkinColor
        {
            get { return skinColor; }
            set
            {
                skinColor = value;
                if (skinColor.GetBrightness() >= 0.8F)
                    calendarIcon = Properties.Resources.calendarDark;
                else calendarIcon = Properties.Resources.calendarWhite;
                this.Invalidate();
            }
        }

        public Color TextColor
        {
            get { return textColor; }
            set
            {
                textColor = value;
                this.Invalidate();
            }
        }

        public Color BorderColor
        {
            get { return borderColor; }
            set
            {
                borderColor = value;
                this.Invalidate();
            }
        }

        public int BorderSize
        {
            get { return borderSize; }
            set
            {
                borderSize = value;
                this.Invalidate();
            }
        }

        //Constructor
        public RJDatePicker()
        {
            this.SetStyle(ControlStyles.UserPaint, true);
            this.MinimumSize = new Size(0, 35);
            this.Font = new Font(this.Font.Name, 9.5F);
        }

        //Overridden methods
        /*
        protected override void OnDropDown(EventArgs eventargs)
        {
            base.OnDropDown(eventargs);
            droppedDown = true;
        }
        */
        private const int SWP_NOMOVE = 0x0002;
        private const int DTM_First = 0x1000;
        private const int DTM_GETMONTHCAL = DTM_First + 8;
        private const int MCM_GETMINREQRECT = DTM_First + 9;

        [DllImport("uxtheme.dll")]
        private static extern int SetWindowTheme(IntPtr hWnd, string appName, string idList);
        [DllImport("user32.dll")]
        static extern IntPtr SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);
        [DllImport("user32.dll")]
        static extern IntPtr SendMessage(IntPtr hWnd, int Msg, int wParam, ref RECT lParam);
        [DllImport("user32.dll")]
        static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter,
        int X, int Y, int cx, int cy, int uFlags);
        [DllImport("User32.dll")]
        private static extern IntPtr GetParent(IntPtr hWnd);
        [StructLayout(LayoutKind.Sequential)]
        private struct RECT { public int L, T, R, B; }
        protected override void OnDropDown(EventArgs eventargs)
        {
            //添加后编译程序，在要使用的界面拖动用户控件使用即可，弹出窗口的大小会根据CalendarFont决定
            var hwndCalendar = SendMessage(this.Handle, DTM_GETMONTHCAL, 0, 0);
            SetWindowTheme(hwndCalendar, string.Empty, string.Empty);
            var r = new RECT();
            SendMessage(hwndCalendar, MCM_GETMINREQRECT, 0, ref r);
            var hwndDropDown = GetParent(hwndCalendar);
            SetWindowPos(hwndDropDown, IntPtr.Zero, 0, 0,
                r.R - r.L + 6, r.B - r.T + 6, SWP_NOMOVE);
            base.OnDropDown(eventargs);
        }

        protected override void OnCloseUp(EventArgs eventargs)
        {
            base.OnCloseUp(eventargs);
            droppedDown = false;
        }
        protected override void OnKeyPress(KeyPressEventArgs e)
        {
            base.OnKeyPress(e);
            e.Handled = true;
        }
        protected override void OnPaint(PaintEventArgs e)
        {
            using (Graphics graphics = this.CreateGraphics())
            using (Pen penBorder = new Pen(borderColor, borderSize))
            using (SolidBrush skinBrush = new SolidBrush(skinColor))
            using (SolidBrush openIconBrush = new SolidBrush(Color.FromArgb(50, 64, 64, 64)))
            using (SolidBrush textBrush = new SolidBrush(textColor))
            using (StringFormat textFormat = new StringFormat())
            {
                RectangleF clientArea = new RectangleF(0, 0, this.Width - 0.5F, this.Height - 0.5F);
                RectangleF iconArea = new RectangleF(clientArea.Width - calendarIconWidth, 0, calendarIconWidth, clientArea.Height);
                penBorder.Alignment = PenAlignment.Inset;
                textFormat.LineAlignment = StringAlignment.Center;

                //Draw surface
                graphics.FillRectangle(skinBrush, clientArea);
                //Draw text
                graphics.DrawString("   " + this.Text, this.Font, textBrush, clientArea, textFormat);
                //Draw open calendar icon highlight
                if (droppedDown == true) graphics.FillRectangle(openIconBrush, iconArea);
                //Draw border 
                if (borderSize >= 1) graphics.DrawRectangle(penBorder, clientArea.X, clientArea.Y, clientArea.Width, clientArea.Height);
                //Draw icon
                graphics.DrawImage(calendarIcon, this.Width - calendarIcon.Width - 9, (this.Height - calendarIcon.Height) / 2);

            }
        }
        protected override void OnHandleCreated(EventArgs e)
        {
            base.OnHandleCreated(e);
            int iconWidth = GetIconButtonWidth();
            iconButtonArea = new RectangleF(this.Width - iconWidth, 0, iconWidth, this.Height);
        }
        protected override void OnMouseMove(MouseEventArgs e)
        {
            base.OnMouseMove(e);
            if (iconButtonArea.Contains(e.Location))
                this.Cursor = Cursors.Hand;
            else this.Cursor = Cursors.Default;
        }

        //Private methods
        private int GetIconButtonWidth()
        {
            int textWidh = TextRenderer.MeasureText(this.Text, this.Font).Width;
            if (textWidh <= this.Width - (calendarIconWidth + 20))
                return calendarIconWidth;
            else return arrowIconWidth;
        }
    }
}