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前言

在研究 ComboBoxRenderer 時，發現 ColoredComboBox ，看它是 Vista Style 蠻好看的，所以就整理成 VistaStyleComboBox ，同時跟大家分享研究!

以下為Windows 7看起來的樣子!

會有 VistaStyle 主要是檢查 OS 是否 Vista 以上的版本，是的話，就使用 ButtonRenderer.DrawButton ，不是的話，就用原本的方式繪出來!

另外，使用 ComboBoxRenderer 還要判斷是否有 Support 才可以使用哦! 完整的Code如下，

using System;
using System.Drawing;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;
//modify from http://bytes.com/topic/c-sharp/answers/635882-inherit-combobox-windows-vista

 
public class VistaStyleComboBox : ComboBox
{
    #region Private Members
        private bool IsVista;
        private ComboBoxState cb_State = ComboBoxState.Normal;
    #endregion

    #region Constructor
        public VistaStyleComboBox()
        {
            this.SetStyle(ControlStyles.AllPaintingInWmPaint, true);
            this.SetStyle(ControlStyles.UserPaint, true);
            //判斷是否vista以上的pc
            IsVista = ((Environment.OSVersion.Version >= new Version("6.0.0")) && (Environment.OSVersion.Platform == PlatformID.Win32NT));
            this.DropDownStyle = ComboBoxStyle.DropDownList;
            this.FlatStyle = FlatStyle.System;
            this.DrawMode = System.Windows.Forms.DrawMode.OwnerDrawFixed;
            this.DrawItem += new DrawItemEventHandler(VistaStyleComboBox_DrawItem);
        }
    #endregion


        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);
            if (Enabled == false)
                cb_State = ComboBoxState.Disabled;
            Rectangle r = e.ClipRectangle;
            if (IsVista)
            {
                PushButtonState pb_State = PushButtonState.Normal;
                if (cb_State == ComboBoxState.Disabled)
                    pb_State = PushButtonState.Disabled;
                else if (cb_State == ComboBoxState.Hot)
                    pb_State = PushButtonState.Hot;
                else if (cb_State == ComboBoxState.Pressed)
                    pb_State = PushButtonState.Pressed;
                
                ButtonRenderer.DrawButton(e.Graphics, r, pb_State);
                r = new Rectangle(r.Right -
                System.Windows.Forms.SystemInformation.VerticalScrollBarWidth + 2,
                e.ClipRectangle.Top,
                System.Windows.Forms.SystemInformation.VerticalScrollBarWidth - 4,
                e.ClipRectangle.Height);
                DrawArrow(e.Graphics, r);
            }
            else
            {
                r = new Rectangle(r.Right -
                System.Windows.Forms.SystemInformation.VerticalScrollBarWidth,
                e.ClipRectangle.Top,
                System.Windows.Forms.SystemInformation.VerticalScrollBarWidth,
                e.ClipRectangle.Height);
                if (ComboBoxRenderer.IsSupported)
                {
                    ComboBoxRenderer.DrawTextBox(e.Graphics, r, cb_State);
                    ComboBoxRenderer.DrawDropDownButton(e.Graphics, r,
                    cb_State);
                }
                else
                {
                    ComboBoxRenderer.DrawDropDownButton(e.Graphics, r,
                    cb_State);
                }
                
            }
            r = e.ClipRectangle;
            r.Inflate(0, -2);
            r.Offset(0, 1);
            DrawItemText(e.Graphics, r, SelectedIndex);
        }

        private void DrawArrow(Graphics g, Rectangle rect)
        {
            Point p1 = new Point(rect.X + 3, rect.Y + rect.Height / 2
            - 2);
            Point p2 = new Point(rect.X + rect.Width - 3, rect.Y +
            rect.Height / 2 - 2);
            Point p3 = new Point(rect.X + rect.Width / 2, rect.Y +
            rect.Height / 2 + 2);
            g.FillPolygon(new
            SolidBrush(System.Drawing.SystemColors.ControlText), new Point[]{p1,
        p2, p3});
        }
        private void DrawItemText(Graphics g, Rectangle r, int Index)
        {
            if (Index == -1 || Items.Count == 0)
                return;
            Color c = ForeColor;

            SolidBrush b = new SolidBrush(c);
            g.DrawString(Items[Index].ToString(), this.Font, b, r);
            b.Dispose();
        }

        protected void VistaStyleComboBox_DrawItem(object sender, DrawItemEventArgs e)
        {
            e.DrawBackground();
            DrawItemText(e.Graphics, e.Bounds, e.Index);
            e.DrawFocusRectangle();
        }

        #region Mouse Movement
        // Draw the smaller pressed button image.
        protected override void OnMouseDown(MouseEventArgs e)
        {
            base.OnMouseDown(e);
            cb_State = ComboBoxState.Pressed;
            Invalidate();
        }

        // Draw the button in the hot state.
        protected override void OnMouseEnter(EventArgs e)
        {
            base.OnMouseEnter(e);
            cb_State = ComboBoxState.Hot;
            Invalidate();
        }

        // Draw the button in the unpressed state.
        protected override void OnMouseLeave(EventArgs e)
        {
            base.OnMouseLeave(e);
            cb_State = ComboBoxState.Normal;
            Invalidate();
        }

        // Draw the button hot if the mouse is released on the button.
        protected override void OnMouseUp(MouseEventArgs e)
        {
            base.OnMouseUp(e);
            OnMouseEnter(e);
        }

        // Detect when the cursor leaves the button area while
        // it is pressed.
        protected override void OnMouseMove(MouseEventArgs e)
        {
            base.OnMouseMove(e);

            // Detect when the left mouse button is down and
            // the cursor has left the pressed button area.
            if ((e.Button & MouseButtons.Left) == MouseButtons.Left &&
            !ClientRectangle.Contains(e.Location) &&
            cb_State == ComboBoxState.Pressed)
            {
                OnMouseLeave(e);
            }
        }

        #endregion
}
 

 

參考資料:

ColoredComboBox

範例程式:

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