asked on

Auto Complete on ComboBox, not working with user defined DrawItem!

Hey guys,

I've got an issue with a Windows application I've written in C# using Visual Studio 2005. With the help of Expert's Exchange, I was able to create a fancy ComboBox that allows different colors for different items. With the use of a special class that was created, I do the following:

I SET / ADD the items in the ComboBox like this:

ListItemSC oItem = new ListItemSC();
oItem.SelColor = Color.Blue;
oItem.Text = strTempstr.ToUpper();
oItem.Value = dataReader["guidPersonID"].ToString();
cBxPlayerList.Items.Add(oItem);

I RETREIVE the items like this:

ListItemSC oItem = (ListItemSC)this.cBxPlayerList.SelectedItem;
String strValue = oItem.Value;
String strText = oItem.Text;
SQL_LoadFromListSelect(strValue)

And I set the DrawItem event of the ComboBox to this:

private void ComboBox_DrawItem(object sender, DrawItemEventArgs e)
{
System.Drawing.Color aColor = new System.Drawing.Color();
if (e.Index >= 0)
{
e.DrawBackground();
String drawString = this.cBxPlayerList.Items[e.Index].ToString();
Font drawFont = new Font("Veranda", 10, FontStyle.Bold);
aColor = ((ListItemSC)this.cBxPlayerList.Items[e.Index]).SelColor;
SolidBrush drawBrush = new SolidBrush(aColor);
PointF drawPoint = new PointF(e.Bounds.X, e.Bounds.Y);
e.Graphics.DrawString(drawString, drawFont, drawBrush, drawPoint);
cBxPlayerList.AutoCompleteMode = AutoCompleteMode.SuggestAppend;
}
}

Everything works GREAT! Except I have ONE major problem....

Auto Complete no longer works.

The Auto Complete is currently set like this:

AutoCompleteMode = SuggestAppend
AutoCompleteSource = ListItems
DrownDownStyle = DropDownList
DrawMode = Normal

Something to note, BEFORE I programmed it to accept colors, etc... the auto complete worked PERFECTLY FINE... ever since I coded it to accept colors (using the DrawItem event) it no longer works.

Any idea what I can do?

Thanks guys, I really appreciate any help...

Bob Learned

Hmmm...setting AutoCompleteMode eventually calls a Windows API:

[DllImport("shlwapi.dll")]
public static extern int SHAutoComplete(HandleRef hwndEdit, int flags);

Why would you be setting AutoCompleteMode in the DrawItem event handler?

dfins

ASKER

Well, for no other reason than I'm trying everything I possibly can. Auto Complete works fine everywhere else in the application, but on this ONE combobox where I'm manipulating the colors / fonts, it doesn't work. It doesn't work whether or not I put it in the event handler or not... I'm just trying everything possible that I can...
I've tried it with, or without, no difference. The options are already set in the properties window anyway.

Any idea?

Bob Learned

I have no idea whatsoever, but maybe I have too narrow a view of your problem. There might be some other code, like an override that I can't see, that would start to explain the root of your problem.

dfins

ASKER

I think the override is the fact that I'm using the OnDrawItem Event... I think that's basically breaking the Auto Complete. The second that I eliminate the OnDrawItem event, the autocomplete starts working again... (but of course the colors / fonts do not).

Bob Learned

You might try calling base.OnDrawItem(sender, e) in the override.

dfins

ASKER

Thanks Learned One, I apologize for the stupid question, but how exactly do I do that?
Where exactly would I put that code?

base.OnDrawItem(sender, e)?
By override, do you mean, the OnDrawItem procedure that I wrote that handles the color coding of the text items?

Bob Learned

Yes, it would be something like this:

    public class CustomComboBox : ComboBox
    {
 
        protected override void OnDrawItem(DrawItemEventArgs e)
        {
            base.OnDrawItem(e);
        }
 
    }

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dfins

ASKER

Thanks, I really appreciate it... this is what I have:
It gives me this error:

Error 1 'AppX.ListItemSC.OnDrawItem(System.Windows.Forms.DrawItemEventArgs)': no suitable method found to Override C:\PROJECTS\AppX\AppX\PlayerForm.cs 1583 33 AppX

    public class ListItemSC
    {
        public ListItemSC()
        {
        }
 
        public ListItemSC(string text, string value, Color color)
        {
            _text = text;
            _value = value;
            _color = color;
        }
        private string _value;
        public string Value
        {
            get { return _value; }
            set { _value = value; }
        }
 
        private string _text;
        public string Text
        {
            get { return _text; }
            set { _text = value; }
        }
 
        protected override void OnDrawItem(DrawItemEventArgs e)
        {
            base.OnDrawItem(e);
        }
 
        public override string ToString()
        {
            return _text;
        }
 
        private Color _color;
        public Color SelColor
        {
            get
            {
                return _color;
            }
            set
            {
                _color = value;
            }
        }
    }

Open in new window

Bob Learned

You need to inherit from ComboBox.

public class ListItemSC : System.Windows.Forms.ComboBox
{

dfins

ASKER

Damn, now I get this...

Warning 1 'AppX.ListItemSC.Text' hides inherited member 'System.Windows.Forms.ComboBox.Text'. To make the current member override that implementation, add the override keyword. Otherwise add the new keyword. C:\PROJECTS\AppX\AppX\PlayerForm.cs 1577 23 AppX

No idea...

It lets me compile, but same result...

Bob Learned

Here is an example of a custom ComboBox:

using System;
using System.Drawing;
using System.IO;
using System.Windows.Forms;
 
namespace SampleControls
{
 
    public class CustomComboBox : ComboBox
    {
 
        public CustomComboBox()
        {
            this.DrawMode = DrawMode.OwnerDrawFixed;
        }
 
        protected override void OnDrawItem(DrawItemEventArgs e)
        {
            string folder = this.Items[e.Index].ToString();
 
            Color foreColor = e.ForeColor;
            Color backColor = e.BackColor;
 
            if (!Directory.Exists(folder))
            {
                foreColor = Color.Red;
                if (e.State == DrawItemState.Selected)
                {
                    backColor = Color.LightPink;
                }
            }
            else
            {
                DirectoryInfo info = new DirectoryInfo(folder);
 
                if ((info.Attributes & FileAttributes.Compressed) == FileAttributes.Compressed)
                {
                    foreColor = Color.Blue;
                    if (e.State == DrawItemState.Selected)
                    {
                        backColor = Color.LightBlue;
                    }
                }
                else if ((info.Attributes & FileAttributes.Encrypted) == FileAttributes.Encrypted)
                {
                    foreColor = Color.Green;
                    if (e.State == DrawItemState.Selected)
                    {
                        backColor = Color.LightGreen;
                    }
                }
            }
 
            using (SolidBrush brush = new SolidBrush(backColor))
            {
                e.Graphics.FillRectangle(brush, e.Bounds);
            }
 
            using (SolidBrush brush = new SolidBrush(foreColor))
            {
                e.Graphics.DrawString(folder, e.Font, brush, e.Bounds);
            }
 
            base.OnDrawItem(e);
        }
 
    }
 
}

Open in new window

Bob Learned

.designer code:

            // 
            // customComboBox1
            // 
            this.customComboBox1.AutoCompleteMode = System.Windows.Forms.AutoCompleteMode.Append;
            this.customComboBox1.AutoCompleteSource = System.Windows.Forms.AutoCompleteSource.FileSystem;
            this.customComboBox1.FormattingEnabled = true;
            this.customComboBox1.Location = new System.Drawing.Point(178, 133);
            this.customComboBox1.Name = "customComboBox1";
            this.customComboBox1.Size = new System.Drawing.Size(189, 21);
            this.customComboBox1.TabIndex = 0;

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Bob Learned

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dfins

ASKER

Thanks, I'll try to digest this and see if I can get it all to work.

Thanks!!!

dfins

ASKER

THANKS!!!