Custom Combo Box

raghuVienna · #1 December 24th, 2008, 10:58 AM

Hello Sir,
Please help me ?
I am createing a custom combo box control in c#.net 3.0 by inherit combo box. in this control i am using OnPaint and OnPaintBackground to paint combo button .
The problem came when paint event fire's, it Black the inner combo box color(is this is nonclient area?).and not show back color in combo's inner area.
and here dropdownstyle=dropdown.

But when i set dropdownstyle=dropdownlist then it will fine. now the problem with this is it will not show the text in combox after drop down list is closed.
Now couldn't find the way how proceds further.
Thanks.

vekipeki · #2 December 24th, 2008, 01:22 PM

You could post some of your code to make it easier to find the problem. Something like this should work anyway (at least when talking about "black background":

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public class CustomCombo : ComboBox

{

    public CustomCombo()

    {

        SetStyle(ControlStyles.UserPaint | 

             ControlStyles.SupportsTransparentBackColor | 

             ControlStyles.OptimizedDoubleBuffer, true);

        this.BackColor = Color.Transparent;

    }
 
    protected override void OnPaint(PaintEventArgs e)

    {

        // custom paint

    }
 
    protected override void OnPaintBackground

            (PaintEventArgs pevent)

    {

        base.OnPaintBackground(pevent);

        // some custom paint code after this

    }

}

raghuVienna · #3 December 26th, 2008, 04:10 AM

Thanks viki:
here is my code:

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using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Drawing;

using System.Data;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using System.Diagnostics;
 
namespace ComboBoxControl

{

    public partial class ComboBoxControl1 : ComboBox

    {

        private static string strcmbo = "";
 
        #region Variables
 
        ControlStyles styleTrue = ControlStyles.AllPaintingInWmPaint|

            ControlStyles.DoubleBuffer |

            ControlStyles.FixedHeight |

            ControlStyles.ResizeRedraw |  

          ControlStyles.UserPaint;   

     private Rectangle m_clickButton;

        private Color _ButtonBackColor;
 
        #region Class Constructor

        public ComboBoxControl1()

        {

            InitializeComponent();
 
            SetStyle(styleTrue, true);

            SetStyle(ControlStyles.Selectable, false); //to recive focuse if true
 
        }

        #endregion
 
        #region Override Events
 
        protected override void OnPaintBackground(PaintEventArgs pevent)

        {

            base.OnPaintBackground(pevent);
 
            Graphics g = pevent.Graphics;

            BorderWidth = comboBox1.Width;

            Rectangle rect = new Rectangle(comboBox1.Location.X, comboBox1.Location.Y, BorderWidth, comboBox1.Height + 3);

            ControlPaint.DrawBorder(g, rect, _ButtonBackColor, ButtonBorderStyle.Solid);
 
            if (this.Text != "")

            {

                strcmbo = this.Text;

                comboBox1.Text = strcmbo;

            }

        }
 
        protected override void OnPaint(PaintEventArgs e)

        {
 
            OnPaintBackground(e);

            OnPaintComboButton(e);
 
            if (this.Text != "")

            {

                strcmbo = this.Text;

                comboBox1.Text = strcmbo;

            }
 
        }
 
        #endregion
 
        #region Virtual Events

        protected virtual void OnPaintComboButtonBackground(System.Windows.Forms.PaintEventArgs pevent)

        {

            Graphics g = pevent.Graphics;

            Rectangle rc = ClientRectangle;

            g.FillRectangle(new SolidBrush(BorderColor), rc.Right - 17, rc.Y + 2, 15, rc.Height - 4);
 
        }
 
        #endregion
 
    }

}

this is main code when i paint combo right side button then it will black the inner color of combo?
please fine some solutions.
Is this non client area of combo box.

insertAlias · #4 December 26th, 2008, 02:12 PM

Please use [code] tags when you post code.

MODERATOR

raghuVienna · #5 December 29th, 2008, 03:17 AM

Thanks Alias.for your Suggestion

Frinavale · #6 December 30th, 2008, 07:04 PM

I've moved your thread to the C# forum.

RedSon · #7 December 30th, 2008, 07:19 PM

Ok... I have no idea what you are asking about. Can you describe or take a screen shot of what it looks like now, and can you describe or make an example of what you want it to look like?

raghuVienna · #8 December 31st, 2008, 03:33 AM

Thanks Everybody, i find solution by redrawing the the text in the combo and overrids the Onpaint event in dropdown style.
Thank
Happy New Year

Custom Combo Box

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