Properties window - accessing collections

[Steve Barnett]

I have created a user control that includes the following field:
[Browsable(true)]
protected TreeColumn[] columns = new TreeColumn[3];

This is accessed via an accessor as follows:
pubilc TreeColumn[] Columns
{
get { return columns; }
set { columns = value; }
}

Now, at design time, I can see the "Columns" property in the property editor
and I can expand it to show three items. However, I want to be able to
change the values of these three columns, but VS has made them read only, so
will not let me make any changes.

Any suggestions as to how I get access to the public properties of the
TreeColum class?

On a second point, I get a button I can click that opens the collection
editor. This gives me add and remove buttons that are not helpful. I need my
array fixed at 3 items. Pressing the add button causes an error message -
can I either suppress the collection editor or can I remove these buttons?

Thanks
Steve

 

[Guest]

Hi.
Use class inherited from ExpandableObjectConverter and its CanConvertTo and
CanConvertFrom methods for editing or displaying the items of your array. You
can find detailed info in MSDN.
The second question is still opened even for me. I do not know how to
disable/suppress collection editor button in the property grid too. Does
anybody know?
Thanks.

 

[Jamie Bissett]

You will have to write a custom editor for you're spefic attributes and
specy that UIEditor in the attributes of the item. This will then display
you're own editor -- without using the default Collections editor -- hence
no button.

Jamie

 

[Guest]

Hi. Thanks. I found this solution too. But when I created my own UIEditor it
didn't work for the property of the List<MyClass> type. May be List<> generic
defines its own CollectionEditor. I tryied to create my own editor for other
types and it worked. Does anybody know how to change UIEditor for the List<>
generic?
Thanks once more time.
B.

 

[Jamie Bissett]

Here's s simple one I use -- this works OK, the dialog tha tthis code is
showing is just a simple 2 column datagrid view with key value pairs -- it
seems similar to what you are trying to do.

class CostEditor : UITypeEditor
{
private IWindowsFormsEditorService editorService = null;

public override UITypeEditorEditStyle
GetEditStyle(System.ComponentModel.ITypeDescriptorContext context)
{
return UITypeEditorEditStyle.Modal;
}

public override object EditValue(
ITypeDescriptorContext context,
IServiceProvider provider,
object value)
{
if (provider != null)
{
editorService =
provider.GetService(
typeof(IWindowsFormsEditorService))
as IWindowsFormsEditorService;
}

if (editorService != null)
{
Prices frm = new Prices((Dictionary<string, decimal>)value);
frm.ShowDialog();
if (frm.DialogResult == DialogResult.OK) return value;
}

return null;

}

Then where you define the Property you need the following

[Description("This indicate whether this is a menu that is
called on start of a POS device."),
Category("Prices"),
Editor(typeof(CostEditor), typeof(UITypeEditor))]
/// <Summary>
/// Returns the prices for all plans that apply to this item
/// </Summary>
public Dictionary<string, decimal> Prices
{
get { return _Prices; }
}

This way still presents the button to display the editor, but it displays my
grid not the default collection editor. My DataGridView is disabled for
editing, but if you allow editing and define the set in the property, and
also define the attribute [ReadOnly(False)] this will allow you to edit
you're values in you;re own dialog.

Hope this helps

Jamie

 

[Guest]

Now you opened my eyes. The problem of my code is that, I didn't inherit my
editor class directly from UITypeEditor but from CollectionEditor class which
is ancestor of UITypeEditor. I just wanted to suppress displaying the edit
button in the PropertyGrid for some conditions. But it seem to be impossible
to inherit correctly the new class from the CollectionEditor class. When I
put the breakpoint into the constructor of the class inherited of
CollectionEditor the programm doesn't stop there. Probably my editor is not
created even I specified the EditorAttribute correctly for my property.

This is non-properly working code:
public class iSTConfigVar
{
public string name = string.Empty;
public string value = string.Empty;
}

public class BLVarsEditor : CollectionEditor
{
public BLVarsEditor()
: base(typeof(List<iSTConfigVar>))
{
}

public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext
context)
{
return UITypeEditorEditStyle.None;
//return base.GetEditStyle(context);
}
}



private List<iSTConfigVar> tralala = new List<iSTConfigVar>();

[EditorAttribute(typeof(BLVarsEditor), typeof(CollectionEditor))]
public List<iSTConfigVar> TestListGenericValue
{
get
{
return tralala;
}
set
{
tralala = value;
}
}


This is working code:
public class iSTConfigVar
{
public string name = string.Empty;
public string value = string.Empty;
}

public class BLVarsEditor : UITypeEditor
{
public BLVarsEditor()
{
}

public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext
context)
{
return UITypeEditorEditStyle.None;
//return base.GetEditStyle(context);
}
}



private List<iSTConfigVar> tralala = new List<iSTConfigVar>();

[EditorAttribute(typeof(BLVarsEditor), typeof(UITypeEditor))]
public List<iSTConfigVar> TestListGenericValue
{
get
{
return tralala;
}
set
{
tralala = value;
}
}

The only difference is, the first editor is inherited directly from
UITypeEditor and the second is inherited from CollectionEditor.

Thanks for any help.
B.

 

[Guest]

I forgot to write question. Does anybody know if it is possible inherit class
from the CollectionEditor and change the behavior of newly inherited class?
Thanks.
B.