Wpf command canexecute not updating
Please give an explaination to this case and if possible, point out some related articles or blogs (I've already read too many articles talking about cut/paste command).
is called: WPF will invoke it when it thinks it is appropriate, and in my experience this will almost always cover your requirements.
Also, I up-voted your answer immediately, then took the vote back to see whether it worked. Thanks @Arcturus Just an FYI I commented out Command Manager.
Now that it's working, I can't re-apply the vote again. I had the same problem happening when I was changing the content of a Texbox from the code-behind. In this app, they had the texbox being edited by a control that would popup, and when you saved the popup, it would change the Texbox. Requery Suggested = value; I was getting a near constant/looping evaluation of my Can Execute code for some reason.
New(execute, Nothing) End Sub Public Sub New(By Val execute As Action, By Val can Execute As Func(Of Boolean)) If execute Is Nothing Then Throw New Argument Null Exception("execute") End If _Execute = execute _Can Execute = can Execute End Sub #End Region #Region "ICommand" Public Custom Event Can Execute Changed As Event Handler Implements System. Requery Suggested, value End If End Remove Handler Raise Event(By Val sender As Object, By Val e As System. Can Execute If _Can Execute Is Nothing Then Return True Else Return _Can Execute. WPF will use any local change to requery commands states, so, for example, if you click a button, or click the form, or if the change of the command state occurs as a result of a button click for example, this change will show without manually needing to prod the command.
Although writting WPF application for some time, I'm new to WPF Command.
@Coding Gorilla It is a b/g thread, however when it finishes awaiting, the ' Is Running = false' takes place on the UI thread.
I've used the same technique within commands on other views/VMs without [email protected] MAX I saw something similar here: stackoverflow.com/a/19684334/981831.
Invalidate Requery Suggested and i tried to use their some times but i don't know how to do it properly and it didn't take an effect. Set it to true whenever you change any field (add logic to the setters for properties to do this) and have your save command check the isdirty, run validation and then submit if all conditions are met.
If you want to get really fancy, look into using the IObservable interface. I don't know how you have set the "Data Context" of your view to your view model, but assuming that is all correct and no issue, adjust the textbox and command button to something like Notice the text binding is to the "Entity" object on your MVVM and then the ". The important thing here is the Update Source Trigger.When I click my "Start" button (bound to 'Start Command'), the "Save" button is correctly disabled.