I have three custom action buttons on a list created through SharePoint Designer. All three buttons execute a workflow and I need to show/hide or enable/disable the buttons based on certain conditions (e.g. workflow has been executed already, or a value in a column).
[edit, taken from comments]
As far as I know it can't be done in SPD, so I'm looking for some code written with Visual Studio to change the behaviour of these buttons. [/edit]
Can someone please provide me with some guidance.