RelayCommand is an implementation of the .NET ICommand interface made and described by WPF expert Josh Smith.
Questions tagged [relaycommand]
289 questions
5
votes
1 answer
Button hold down to repeat commands
I have a button in my WPF project and I want to it execute the same command over and over when I hold the button down. I could use RepeatButton but my preference would be for the command to execute again as soon as it is done running (in its own…
AClark
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5
votes
1 answer
Why is param in this lambda expression?
The MSDN magazine article by Josh Smith on MVVM contains a lambda expression I don't completely understand. What is the purpose of param in this code?
_saveCommand = new RelayCommand(param => this.Save(),
param => this.CanSave…
DeveloperDan
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4
votes
2 answers
RelayCommand RaiseCanExecuteChanged() fails
I am using a couple of Buttons bound to RelayCommands initialized with CanExecute delegates.
RelayCommand DeleteCommand;
bool CanDelete()
{
return BoolProp1 && BoolProp2;
}
...
DeleteCommand = new RelayCommand(Delete, CanDelete);
BoolProp1…
Jacek Gorgoń
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4
votes
2 answers
Pass CommandParameter to Command in Silverlight using MVVM
I'm just learning Silverlight and looking at MVVM and Commanding.
Ok, so I have seen the basic RelayCommand implementation:
public class RelayCommand : ICommand
{
private readonly Action _handler;
private bool _isEnabled;
public…
Mike
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4
votes
1 answer
Cannot find GalaSoft.MvvmLight.CommandWpf namespace in MVVM Light 5.2.0.37222
I just tried to update one of my WPF projects from MVVM Light 4.2.30 to 5.2. After that I noticed that my RelayCommands do not fire their CanExecute methods anymore.
After a quick search I found several articles that explain the problem and suggest…
Ralf
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4
votes
1 answer
Can't pass a single parameter to lambda function in MVVM Light Toolkit's RelayCommand
I don't know if there's a difference between Josh Smith's and Laurent Bugnion's implementations of RelayCommand or not, but everywhere I've looked, it sounds like the Execute portion of RelayCommand can take 0 or 1 parameters. I've only been able…
Dave
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4
votes
2 answers
RelayCommand Memory leak
I am looking for an implementation of RelayCommand. The original implementation that I considered was the classic one (lets call it implementation A)
public class RelayCommand : ICommand
{
private readonly Predicate
Kobi Hari
- 1,259
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4
votes
3 answers
CanExecute() not enabling button when condition is met
I have a very simple application with a TextBox and a Button. When the text entered into the TextBox exceeds 5 characters in length, the button will be enabled. Here is the code for my ViewModel:
private string _text { get; set; }
public string…
user3761858
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4
votes
1 answer
Binding CommandParameter on ItemsControl Tap event
I'm using an ItemsControl, and I want to identify which item was selected on the Tap command. My xaml is defined here:
…
earthling
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3
votes
3 answers
Best / neatest way to declare RelayCommands
I've been trying to find a nice neat and succinct way to declare RelayCommands in my ViewModels.
The best I can come up with is:
public class MyViewModel
{
public ICommand StopCommand { get; private set; }
public MyViewModel()
{
…
GazTheDestroyer
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3
votes
1 answer
object sender is always null in RelayCommand
I am using RelayCommand to handle a button click, I need to get the sender parameter but it is always null, any idea why?
ViewModel.cs
private RelayCommand _expandClickCommand;
public ICommand ExpandClickCommand
{
get
{
…
Eamonn McEvoy
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3
votes
2 answers
Moving RelayCommand (CommandManager) from .Net Framework to .NET Core v3.0.100-preview3
My RelayCommand includes the implementation of CommandManager which is not known by .net core 3 preview 3. However, Microsoft says the it is available: see here
I installed/uninstalled .Net Core and restarted visual studio 2019 preview but without…
Sorush
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3
votes
4 answers
Command binding in multiwindow WPF app
My application can have multiple designer windows. Each window constitutes of several user controls which communicates dynamically with the help of RelayCommands. I created the following class as the backbone of the commanding infrastructure.
public…
Jimmy
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3
votes
1 answer
How do I test Relaycommand?
I'm reading this
MSDN Article about MVVM. I'm currently looking at the RelayCommand in figure #15. Pretend I wanted to test this SaveCommand. How would I do that? I'm using NUnit and Rhino Mocks 3.6
Ols1
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3
votes
1 answer
Same method for multiple controls when using Caliburn.Micro
In WPF MVVM application, I need same functionality for multiple controls - for example certain button does same thing as certain menu item. It is piece of cake with MVVM Light's RelayCommand, but I am now using Caliburn.Micro, where almost…
Ondřej
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