| Printable Version
Owner Draw ComboBox
By Shripad Kulkarni
| Download : Source
Code |
|
To do some custom
drawing and painting with any of the windows controls, you need to do
the drawing of the control yourself. The "OwnerDraw" property
of the control will allow you to accomplish this. In this article we will
try to custom draw a ComboBox..
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| Step
1: Create a simple windows form project and add a combo box from
the windows control toolbox into the form. |
| In the properties for
the combobox set the DrawMode option to "OwnerDrawFixed". |
|
When the item is owner
drawn , the application will send the DrawItem
& MeasureItem event to
allow us to do all the custom drawing.
private void comboBox1_DrawItem(object sender, System.Windows.Forms.DrawItemEventArgs e)
For every item that needs to be drawn the DrawItemEventArgs parameter will contain the index of the item to draw. It also contains the graphics
object that we will use to do all the drawing and painting. Here is a simple example ( The Font Combo Box )
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private void comboBox2_DrawItem(object sender, System.Windows.Forms.DrawItemEventArgs e)
{
Graphics g = e.Graphics ;
Rectangle r = e.Bounds ;
if ( e.Index >= 0 )
{
Rectangle rd = r ;
rd.Width = rd.Left + 100 ;
Rectangle rt = r ;
r.X = rd.Right ;
SolidBrush b = (SolidBrush)colorArray[e.Index];
g.FillRectangle(b , rd);
StringFormat sf = new StringFormat();
sf.Alignment = StringAlignment.Near;
Console.WriteLine(e.State.ToString());
e.Graphics.DrawRectangle(new Pen(new SolidBrush(Color.Black), 2 ), r );
if ( e.State == ( DrawItemState.NoAccelerator | DrawItemState.NoFocusRect))
{
e.Graphics.FillRectangle(new SolidBrush(Color.White) , r);
e.Graphics.DrawString( b.Color.Name, new Font("Ariel" , 8 , FontStyle.Bold ) , new SolidBrush(Color.Black), r ,sf);
e.DrawFocusRectangle();
}
else
{
e.Graphics.FillRectangle(new SolidBrush(Color.LightBlue) , r);
e.Graphics.DrawString( b.Color.Name, new Font("Veranda" , 12 , FontStyle.Bold ) , new SolidBrush(Color.Red), r ,sf);
e.DrawFocusRectangle();
}
}
}
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| For a OwnerDrawFixed property the MeasureItem function will have
no effect. This function will be activated only for the OwnerDrawVariable
item. |
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