Dynamic IsReadOnly flag... - Grids for WPF Forum

Posted 14 years ago by SledgeHammer01

Version: 10.1.0521

Hi, I saw another thread where you were talking about dynamically changing the IsReadOnly property, but it doesn't seem to work...

I have a class as below:

public class PropertyDescriptorDataAccessorEx : PropertyDescriptorDataAccessor
{
public new bool IsReadOnly
{
get
{
return base.IsReadOnly | b;
}

set
{
b = value;
this.Refresh();
base.OnPropertyChanged("IsReadOnly");
base.OnPropertyChanged("IsReadOnlyInternal");
}
}

protected override bool IsReadOnlyInternal
{
get
{
return base.IsReadOnlyInternal | b;
}
}

}

I insert items dynamically and save the PropertyDescriptorDataAccessorEx refs for two items.

When I get a change notificaition on another item, I call the IsReadOnly = false on the saved refs.

It doesn't redraw the item as read only. Am I missing a step?

Comments (2)

Posted 14 years ago by Actipro Software Support - Cleveland, OH, USA

Hello,

I'm assuming you are referring to this thread: http://www.actiprosoftware.com/Support/Forums/ViewForumTopic.aspx?ForumTopicID=3957

In that thread, the CustomDataPropertyAccessor implements IPropertyDataAccessor directly, and doesn't derive from PropertyDescriptorDataAccessor. In your code, you define IsReadOnly using the "new" keyword. By adding the "new" keyword, your class will compile but your IsReadOnly property will not always be called. Adding "new" is not the same as overridding. I'd recommend reading the following article: http://msdn.microsoft.com/en-us/library/6fawty39(VS.80).aspx

You would need to override IsReadOnly, and you don't need to override IsReadOnlyInternal. So, something like:

public override bool IsReadOnly {
get {
return this.IsReadOnlyReal;
}
}

private bool isReadOnlyReal = false;
public bool IsReadOnlyReal {
get {
return this.isReadOnlyReal;
}
set {
if (this.isReadOnlyReal != value) {
this.isReadOnlyReal = value;
this.OnPropertyChanged("IsReadOnly");
}
}
}

Actipro Software Support

Posted 14 years ago by SledgeHammer01

Oops.. wasn't paying attention to the code :).

The latest build of this product (v24.1.1) was released 2 months ago, which was after the last post in this thread.

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