自定義彈出控件(上)

自定義彈出控件(上)

原理:
用ToolStripDropDown做為自定義控件的容器,在使用時只需調用相應事件彈出這個容器就可以了.
自定義控件必須從ToolStripControlHost類派生,並用我們需要的一個控件進行初始化(這個控件可以是標準控件,也可以是用戶控件).
製作步驟:
1.定義好一個我們需要的控件或直接選擇一個標準控件.
2.定義一個ToolStripControlHost派生類,並用先前定義的那個控件初始化.
3.使用ToolStripDropDown作為容器,將ToolStripControlHost派生類裝入,在需要的地方按設定容器的大小並彈出這個容器.
以下以製作一個DateTimeComboBox為例
1.我們打算直接彈出一個MonthCalendar控件,所以這一步就不用做.
2.定義ToolStripMonthCalendar,它繼承自ToolStripControlHost,並用一個MonthCalendar實例初始化,在這裡可以暴露MonthCalendar的一部分屬性和方法. 

public class ToolStripMonthCalendar : ToolStripControlHost
    {
        // Call the base constructor passing in a MonthCalendar instance.
        //用MonthCalendar初始化
        public ToolStripMonthCalendar() : base(new MonthCalendar()) { }

        public MonthCalendar MonthCalendarControl
        {
            get
            {
                return Control as MonthCalendar;
            }
        }

        // Expose the MonthCalendar.FirstDayOfWeek as a property.
        //暴露FirstDayOfWeek屬性
        public Day FirstDayOfWeek
        {
            get
            {
                return MonthCalendarControl.FirstDayOfWeek;
            }
            set
            {
                value = MonthCalendarControl.FirstDayOfWeek;
            }
        }

        // Expose the AddBoldedDate method.
        //暴露AddBoldedDate方法
        public void AddBoldedDate(DateTime dateToBold)
        {
            MonthCalendarControl.AddBoldedDate(dateToBold);
        }

        // Subscribe and unsubscribe the control events you wish to expose.
        //覆寫顯示下拉控件時調用的函數
        protected override void OnSubscribeControlEvents(Control c)
        {
            base.OnSubscribeControlEvents(c);

            // Cast the control to a MonthCalendar control.
            MonthCalendar monthCalendarControl = (MonthCalendar)c;

            // Add the event.
            monthCalendarControl.DateChanged += new DateRangeEventHandler(OnDateChanged);
        }
        //覆寫隱藏下拉控件時調用的函數
        protected override void OnUnsubscribeControlEvents(Control c)
        {
            base.OnUnsubscribeControlEvents(c);

            // Cast the control to a MonthCalendar control.
            MonthCalendar monthCalendarControl = (MonthCalendar)c;

            // Remove the event.
            monthCalendarControl.DateChanged -= new DateRangeEventHandler(OnDateChanged);
        }

        // Declare the DateChanged event.
        //聲明日期變更事件
        public event DateRangeEventHandler DateChanged;

        // Raise the DateChanged event.
        private void OnDateChanged(object sender, DateRangeEventArgs e)
        {
            if (DateChanged != null)
            {
                DateChanged(this, e);
            }
        }
    }

3.在指定位置彈出容器. 

public partial class DateTimeComboBox : ComboBox
    {
        private const UInt32 WM_LBUTTONDOWN = 0x201;
        private const UInt32 WM_LBUTTONDBLCLK = 0x203;
        private const UInt32 WM_KEYF4 = 0x134;
        private const UInt32 WM_CTLCOLORLISTBOX = 0x0134;
        ToolStripMonthCalendar myTSMonthCalendar;
        ToolStripDropDown tsDD;

        public DateTimeComboBox()
        {
            InitializeComponent();
            myTSMonthCalendar = new ToolStripMonthCalendar();
            tsDD = new ToolStripDropDown();

            // 事件調用,如果在彈出控件時並不想改變控件的屬性,這步可省略.
            this.myTSMonthCalendar.MonthCalendarControl.DateChanged += new System.Windows.Forms.DateRangeEventHandler(this.myTSMonthCalendar_DateChanged);
            this.myTSMonthCalendar.MonthCalendarControl.KeyDown += new System.Windows.Forms.KeyEventHandler(this.myTSMonthCalendar_KeyDown);
        }

        #region 事件
        private void myTSMonthCalendar_DateChanged(object sender, DateRangeEventArgs e)
        {
            this.Text = e.End.ToShortDateString();
        }
        private void myTSMonthCalendar_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Enter)
                this.tsDD.Close();

        }
        #endregion

        #region 方法,計算容器在彈出時的左上角坐標

 //這個函數有個點問題,它沒有考慮到彈出容器超出屏幕的情況.
        private Point CalculatePoz()
        {
            Point point = new Point(0, this.Height);

            if ((this.PointToScreen(new Point(0, 0)).Y + this.Height + this.myTSMonthCalendar.Height) > Screen.PrimaryScreen.WorkingArea.Height)
            {
                point.Y = -this.myTSMonthCalendar.Height - 7;
            }

            return point;
        }
        #endregion

        protected override void WndProc(ref Message m)
        {
            #region WM_KEYF4
            if (m.Msg == WM_KEYF4)
            {
                this.Focus();
                this.tsDD.Refresh();
                if (!this.tsDD.Visible)
                {
                    try
                    {
                        if (this.Text != "")
                            this.myTSMonthCalendar.MonthCalendarControl.SetDate(Convert.ToDateTime(this.Text));
                    }
                    catch (Exception)
                    {
                        MessageBox.Show("Data nu este in formatul corect!");
                    }
       //在彈出容器中添加項目
                    tsDD.Items.Add(this.myTSMonthCalendar);
                    //彈出容器
                    tsDD.Show(this, this.CalculatePoz());
                }

                return;
            }
            #endregion

            #region WM_LBUTTONDBLCLK
            if (m.Msg == WM_LBUTTONDBLCLK || m.Msg == WM_LBUTTONDOWN)
            {
                if (!this.tsDD.Visible)
                {
                    try
                    {
                        if (this.Text != "")
                            this.myTSMonthCalendar.MonthCalendarControl.SetDate(Convert.ToDateTime(this.Text));
                    }
                    catch (Exception)
                    {
                        MessageBox.Show("Data nu este in formatul corect!");
                    }
                    //在彈出容器中添加項目
                    tsDD.Items.Add(this.myTSMonthCalendar);
                    //彈出容器
                    tsDD.Show(this, this.CalculatePoz());
                }
                return;
            }
            #endregion

            base.WndProc(ref m);
        }
    }

參考文獻:1.http://hi.baidu.com/pzy84/blog/item/22f4ef77bfd94619b151b92c.html