PropertyGrid - how to display a string array as dropdown property

[Steve]

I am using a property grid to display a classes properties, all is OK for
single value properties but i need to display a list of strings for the user
to select from and update the property value based on the selection.
A Drop down list in the property grid would be ideal.
For instance - like the StartPosition property of a form in the IDE.

I think this would be a simple and often used procedure but i have not been
able to locate an example of the code required, can anyone advise?

[Marc Gravell]

Re: PropertyGrid - how to display a string array as dropdown property

Normally this would be done via the type-converter of the property-type
(string in this case), which you obviously can't change in this
scenario. You could encapsulate the string into a simple class, and set
the converter for that, otherwise just set the converter for the
property:

using System;
using System.Componen tModel;
using System.Windows. Forms;
public class MyTest
{
private int test1;
public int Test1
{
get { return test1; }
set { test1 = value; }
}
private string test2;
[TypeConverter(t ypeof(StringLis tConverter))]
public string Test2
{
get { return test2; }
set { test2 = value; }
}
}
public class StringListConve rter : TypeConverter
{
public override bool
GetStandardValu esSupported(ITy peDescriptorCon text context)
{
return true; // display drop
}
public override bool
GetStandardValu esExclusive(ITy peDescriptorCon text context)
{
return true; // drop-down vs combo
}
public override StandardValuesC ollection
GetStandardValu es(ITypeDescrip torContext context)
{
// note you can also look at context etc to build list
return new StandardValuesC ollection(new string[] { "abc",
"def", "ghi" });
}
}
class Program
{
static void Main()
{
using (Form f = new Form())
using(PropertyG rid pg = new PropertyGrid())
{
pg.Dock = DockStyle.Fill;
pg.SelectedObje ct = new MyTest();
f.Controls.Add( pg);
Application.Run (f);
}
}
}

[Steve]

Re: PropertyGrid - how to display a string array as dropdown property


Thanks, works fine, I would like to extend my use of the Property grid
to include objects within objects that would also be viewable/updateable
within the one property grid.
Can you point me in the direction of tutorial type documentation for
property grid, the help doc explanations are difficult for me to grasp?

rgds,Steve

"Marc Gravell" <marc.gravell@g mail.comwrote in message
news:1166161255 .607534.57330@7 9g2000cws.googl egroups.com...

Normally this would be done via the type-converter of the property-type
(string in this case), which you obviously can't change in this
scenario. You could encapsulate the string into a simple class, and set
the converter for that, otherwise just set the converter for the
property:
>
using System;
using System.Componen tModel;
using System.Windows. Forms;
public class MyTest
{
private int test1;
public int Test1
{
get { return test1; }
set { test1 = value; }
}
private string test2;
[TypeConverter(t ypeof(StringLis tConverter))]
public string Test2
{
get { return test2; }
set { test2 = value; }
}
}
public class StringListConve rter : TypeConverter
{
public override bool
GetStandardValu esSupported(ITy peDescriptorCon text context)
{
return true; // display drop
}
public override bool
GetStandardValu esExclusive(ITy peDescriptorCon text context)
{
return true; // drop-down vs combo
}
public override StandardValuesC ollection
GetStandardValu es(ITypeDescrip torContext context)
{
// note you can also look at context etc to build list
return new StandardValuesC ollection(new string[] { "abc",
"def", "ghi" });
}
}
class Program
{
static void Main()
{
using (Form f = new Form())
using(PropertyG rid pg = new PropertyGrid())
{
pg.Dock = DockStyle.Fill;
pg.SelectedObje ct = new MyTest();
f.Controls.Add( pg);
Application.Run (f);
}
}
}
>

[Marc Gravell]

Re: PropertyGrid - how to display a string array as dropdown property

More example than tutorial; for what you want, the main thing is to
specify something like ExpandableObjec tConverter as a type descriptor.
However, much much more customisation is possible.

Example:

http://www.codeproject.com/cs/miscctrl/customizingcollectiondata.asp

Marc

[Marc Gravell]

Re: PropertyGrid - how to display a string array as dropdown property

descrpitor: I meant converter...

"Marc Gravell" <marc.gravell@g mail.comwrote in message
news:1166169715 .353340.105660@ t46g2000cwa.goo glegroups.com.. .

More example than tutorial; for what you want, the main thing is to
specify something like ExpandableObjec tConverter as a type
descriptor.
However, much much more customisation is possible.
>
Example:
>

http://www.codeproject.com/cs/miscctrl/customizingcollectiondata.asp

>
Marc
>