Advanced ListBox

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• Download demo project - 13 Kb

Introduction

Some Times you may need a list box with Header and able to Move in Runtime by User Click!
In this Article we design a List Box with Header , Disposable and movable , ...

Background

    <FONT color=#0000ff>public class</FONT> tblListBox : <FONT color=#cc99ff>Panel</FONT>
    {
        <FONT color=#0000ff>private</FONT> <FONT color=#cc99ff>System.Windows.Forms.CheckedListBox</FONT> listBox1;
<FONT color=#009933>        // Class Detail...</FONT>
    }

For Movable , Disposable , Header Text, Header Color feature we need some private variable

<FONT color=#0000ff>bool</FONT>     isDrag = <FONT color=#0000ff>false</FONT>;            <FONT color=#008000>// For Movable feature</FONT>
<FONT color=#0000ff>long</FONT>     _tblID;                <FONT color=#008000>// for table ID</FONT>
<FONT color=#0000ff>string</FONT>     _hText;                <FONT color=#008000>// For Header text</FONT>
<FONT color=#0000ff>Color</FONT>     _HeaderColor = <FONT color=#cc99ff>Color</FONT>.<FONT color=#0000ff>Blue</FONT>;    <FONT color=#008000>// For Header Back Color</FONT>
<FONT color=#0000ff>bool</FONT>     _Disposable =<FONT color=#0000ff> false</FONT>;        <FONT color=#008000>// For Disposable feature</FONT>
<FONT color=#0000ff>bool</FONT>     _Movable = <FONT color=#0000ff>false</FONT>;        <FONT color=#008000>// For Movable feature</FONT>

Constructor:

<FONT color=#0000ff>public</FONT> tblListBox(<FONT color=#0000ff>long</FONT> TableID)
{
    InitializeComponent();
    _tblID = TableID;
    listBox1.Size = <FONT color=#0000ff>new</FONT> Size(<FONT color=#0000ff>this</FONT>.Size.Width, <FONT color=#0000ff>this</FONT>.Size.Height - 30);
    listBox1.Top = 30;
    <FONT color=#0000ff>this</FONT>.Controls.Add(listBox1);
    <FONT color=#0000ff>this</FONT>.MouseMove += <FONT color=#0000ff>new</FONT> <FONT color=#008080>MouseEventHandler</FONT>(ListMouseMove);
    <FONT color=#0000ff>this</FONT>.MouseDown += <FONT color=#0000ff>new</FONT> <FONT color=#008080>MouseEventHandler</FONT>(ListMouseDown);
    <FONT color=#0000ff>this</FONT>.MouseUp += <FONT color=#0000ff>new</FONT> <FONT color=#008080>MouseEventHandler</FONT>(ListMouseUp);
    <FONT color=#0000ff>this</FONT>.DoubleClick += <FONT color=#0000ff>new</FONT> <FONT color=#008080>EventHandler</FONT>(tblListBox_DoubleClick);
}

Implementing Class:

 <FONT color=#0000ff>public</FONT> <FONT color=#0000ff>int</FONT> SelectedIndex
 {
     <FONT color=#0000ff>get</FONT> { <FONT color=#0000ff>return</FONT> listBox1.SelectedIndex; }
 }
 <FONT color=#0000ff>public bool</FONT> Disposable
 {
     <FONT color=#0000ff>get</FONT> { <FONT color=#0000ff>return</FONT> _Disposable; }
     <FONT color=#0000ff>set</FONT> { _Disposable = <FONT color=#0000ff>value</FONT>; }
 }
<FONT color=#0000ff> public bool</FONT> Movable
 {
     <FONT color=#0000ff>get</FONT> { <FONT color=#0000ff>return</FONT> _Movable; }
     <FONT color=#0000ff>set</FONT> { _Movable = <FONT color=#0000ff>value</FONT>; }
 }

<FONT color=#0000ff> public string</FONT> HeaderText
 {
     <FONT color=#0000ff>get</FONT> { <FONT color=#0000ff>return</FONT> _hText; }
     <FONT color=#0000ff>set</FONT> { _hText = <FONT color=#0000ff>value</FONT>; }
 }
 <FONT color=#0000ff>public long</FONT> TableID
 {
     <FONT color=#0000ff>get</FONT> { <FONT color=#0000ff>return</FONT> _tblID; }
 }
 <FONT color=#0000ff>public Color</FONT> HeaderColor
 {
     <FONT color=#0000ff>get</FONT> { <FONT color=#0000ff>return</FONT> _HeaderColor; }
     <FONT color=#0000ff>set</FONT> { _HeaderColor = <FONT color=#0000ff>value</FONT>; }
 }

Now Implementing two property of ListBox: Items, GetItemChecked(int)

<FONT color=#0000ff>public</FONT> <FONT color=#0000ff>bool</FONT> GetItemChecked(<FONT color=#0000ff>int</FONT> index)
{
    <FONT color=#0000ff>return</FONT> listBox1.GetItemChecked(index);
}

<FONT color=#0000ff>public</FONT> <FONT color=#008080>System.Windows.Forms.ListBox.ObjectCollection</FONT> Items
{
    <FONT color=#0000ff>get</FONT> { <FONT color=#0000ff>return</FONT> listBox1.Items; }
}

Now We Need when Panel Resized The ListBox Resized too and Paint New Feature!:

        <FONT color=#0000ff>protected</FONT> <FONT color=#0000ff>override</FONT> <FONT color=#0000ff>void</FONT> OnResize(<FONT color=#008080>EventArgs</FONT> eventargs)
        {
            listBox1.Size = <FONT color=#0000ff>new</FONT> Size(this.Size.Width, this.Size.Height - 30);
        }
        <FONT color=#0000ff>protected</FONT> <FONT color=#0000ff>override</FONT> <FONT color=#0000ff>void</FONT> OnPaint(<FONT color=#008080>PaintEventArgs</FONT> e)
        {
            
            <FONT color=#008080>Brush</FONT> b=<FONT color=#0000ff>new</FONT> <FONT color=#008080>SolidBrush</FONT>(_HeaderColor);
<FONT color=#008000>            // Paint orginall</FONT><FONT color=#008080>
</FONT>            <FONT color=#0000ff>base</FONT>.OnPaint(e);
<FONT color=#008000>            // Draw background and fill with _HeaderColor
</FONT>            e.Graphics.FillRectangle(b, e.ClipRectangle);
<FONT color=#008000>            // Determine size of string</FONT>
            <FONT color=#008080>SizeF</FONT> strSize=e.Graphics.MeasureString(_hText,<FONT color=#0000ff>new</FONT> <FONT color=#008080>Font</FONT>("Tahoma",8,<FONT color=#008080>FontStyle</FONT>.Bold));
<FONT color=#008000>            // Align Center</FONT>
            float left = e.ClipRectangle.Width/2 - strSize.Width / 2;
<FONT color=#008000>            // Draw string on Center of Header
</FONT>            e.Graphics.DrawString(_hText, <FONT color=#0000ff>new</FONT> <FONT color=#008080>Font</FONT>("Tahoma", 8, <FONT color=#008080>FontStyle</FONT>.Bold), System.Drawing.<FONT color=#008080>Brushes</FONT>.Yellow, <FONT color=#0000ff>new</FONT> <FONT color=#008080>PointF</FONT>(left, 10));
        }

Implementing Movable Feature:

<FONT color=#0000ff>void</FONT> ListMouseMove(<FONT color=#0000ff>object</FONT> sender, MouseEventArgs e)
{
    <FONT color=#0000ff>if</FONT> (!_Movable) <FONT color=#0000ff>return</FONT>;
    tblListBox list = (tblListBox)sender;
    <FONT color=#0000ff>if</FONT> (isDrag)
    {
        Point endPoint = <FONT color=#0000ff>this</FONT>.PointToScreen(<FONT color=#0000ff>new</FONT> Point(e.X - <FONT color=#0000ff>this</FONT>.Parent.Location.X-100, e.Y - <FONT color=#0000ff>this</FONT>.Parent.Location.Y-100));
        list.Location = endPoint;
    }
}
<FONT color=#0000ff>void</FONT> ListMouseUp(<FONT color=#0000ff>object</FONT> sender, MouseEventArgs e)
{
    <FONT color=#0000ff>if</FONT> (!_Movable) <FONT color=#0000ff>return</FONT>;
    isDrag = <FONT color=#0000ff>false</FONT>;
}
<FONT color=#0000ff>void</FONT> ListMouseDown(<FONT color=#0000ff>object</FONT> sender, MouseEventArgs e)
{
    <FONT color=#0000ff>if</FONT> (!_Movable) <FONT color=#0000ff>return</FONT>;
    <FONT color=#0000ff>if</FONT> (e.Button == MouseButtons.Left)
    {
        isDrag = <FONT color=#0000ff>true</FONT>;
    }
    Control control = (Control)sender;
}

Properties: