Ribbon - Prism - OpenFile Command

Ribbon for WPF Forum

Posted 5 years ago by Stephane Franiatte
Version: 14.2.0610


I am currently testing the Ribbon, although this is not a question directly related to this control. I have a DelegateCommand, OpenFileCommand, which can take a String (the file path), but not necessarly (the same command is used to open the Open File Dialog, in case the String is Null). I get the following error, at runtime:

Unable to cast object of type 'ActiproSoftware.Windows.Controls.Ribbon.Input.CheckableCommandParameter' to type 'System.String'

Here is a workaround I found:

<!--Open Button-->
                <ribbon:Button Label="Open" 
                               Command="{x:Static module:ModuleCommands.OpenFileCommand}"
                               CommandParameter=" "/>

 And in my function, I use IsNullOrWhiteSpace to trigger the opening of the Open File Dialog.

However, I would like to avoid doing this, I am sure there is a way to handle DelegateCommand(Of String) properly?


[Modified 5 years ago]

Comments (2)

Posted 5 years ago by Actipro Software Support - Cleveland, OH, USA

Hi Stephane,

The ribbon:Button control has a CheckableCommandParameter instance in CommandParameter by default.  By specifying a value as you do there, you force it to a string instead.  You might also be able to set it to "{x:Null}" instead of " ".  That's the only other suggestion I'd have.

Actipro Software Support

Posted 5 years ago by Stephane Franiatte


yeah, that's what I thought. That is not a really big deal anyway; I am more concerned about my other problem (see my other post).


The latest build of this product (v2019.1 build 0683) was released 19 days ago, which was after the last post in this thread.

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