System.ComponentModel.Design.ArrayEditor - How to

[Peter Ehli]

I have a custom control which is a set of tab images like in hotmail. In my control I have a hard coded array that sets the string
value of the tabs.

private String[] tabCaptions = { "Home", "Tab 1", "Tab 2", "Tab 3" };

I would like these tab captions set by the user of my control via the properties window. i.e. the code below that I have so far.

using System;
using System.ComponentModel.Design;

namespace NetParadigm.WebServerControls
{
public class TabEditor : ArrayEditor
{
public TabEditor() : base (typeof ( String ) )
{
}
}
}

Then I specify this editor via the editor attribute for my TabCaptions property as below

private String[] tabCaptions;

[EditorAttribute("TabEditor",typeof(System.Drawing.Design.UITypeEditor))]
public String[] TabCaptions
{
get
{
return tabCaptions;
}
set
{
tabCaptions = value;
}
}

This is just stubbed code and as far as I could get. This gives me an editor (i.e. click on the ellipse) window exactly like a
windows forms textbox when you set the Lines property values.

When these string values are set via this edior when my control is on a aspx page I get the below in Html view for the control

<cc1:NP_TabStrip id=NP_TabStrip1 runat="server" TabCaptions="String[] Array">

Of course I need to persist these values via view state and TabCaptions="String[] Array" bombs big time!

I've searched everywhere for an example of how to set a string array in my control and come up with a lot of fragments and unrelated
stuff. The Kothari book has an example of a CollectionEditor that is way too complex to disseminate for my use. Any ideas or a good
example of how to do this would be greatly appreciated. Thanks in advance.

Peter Ehli

 

[ChrisAdams]

You need to change the default serialization behaviour that the designer uses
by
adding attributes to the property.

[DesignerSerializationVisibility( DesignerSerializationVisibility.Content ),
PersistenceMode( PersistenceMode.Attribute )]

This should force the dte to serialize the content of your property ie the
string values, instead of the property itself, ie an array.

Chris

 

[Peter Ehli]

Hi Chris,
My property attributes are below and as you can see I added the DesignerSerializationVisibility and PersistenceMode attribute to my
property as you suggested.

[EditorAttribute( "TabEditor",typeof( System.Drawing.Design.UITypeEditor )),
DesignerSerializationVisibility( DesignerSerializationVisibility.Content ),
PersistenceMode( PersistenceMode.Attribute )]
public String[] TabCaptions
{
get
{
return tabCaptions;
}
set
{
tabCaptions = value;
}
}

private String[] tabCaptions;

When I set the string values i.e. TabCaptons via the editor for my control on an aspx page I get the below in Html view from the
aspx page.

<cc1:NP_TabStrip id=NP_TabStrip1 runat="server" TabCaptions-Rank="1" TabCaptions-IsReadOnly="False"
TabCaptions-SyncRoot="System.String[]" TabCaptions-IsSynchronized="False" TabCaptions-IsFixedSize="True" TabCaptions-Length="4"
TabCaptions-LongLength="4" TabCaptions="String[] Array">

This gives me a parser error below when trying to render the page in the browser

Parser Error Message: Cannot create an object of type 'System.String[]' from its string representation 'String[] Array' for the
'TabCaptions' property.

Again below is my designer class.

using System;
using System.ComponentModel.Design;

namespace NetParadigm.WebServerControls
{
public class TabEditor : ArrayEditor
{
public TabEditor() : base (typeof ( String ) )
{
}
}
}

Any ideas on whats wrong? Thanks Chris!

<nospam="(e-mail address removed)"/><nospam>

 

[ChrisAdams]

Whoops,

I forgot that it only works for properties that expose a collection object,
and you need to
persist it as an inner property.

What you probably need to do is specify the TypeConverter that should be
used to get
it from an array to a string representation. Take a look at ArrayConverter
and the
attribute you need to apply is.

[TypeConverter( typeof( System.ComponentModel.ArrayConverter) )]

Chris.

 

[Peter Ehli]

Thanks Chris, I believe my next step is to work through chapter 10 and the examples of the Kothari book. This chapter explains
typeconveters, inner
property persistence, and designer serialization and so forth. Again many thanks for pointing me in the right direction.

Peter Ehli