How to use Commands in MVVM

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my model :

C#

class Login
    {
        public string Name{ get; set; }
        public string Password { get; set; }
    }

my view model :

XML

class LoginViewModel : ObservableObject, INotifyPropertyChanged, ICommand
   {
       class LoginViewModel
       {
           Models.Login _mylogin = new Models.Login();
       }
   }

C#

private readonly Models.Login _mylogin;
        public string Name
        {
            get { return _mylogin.Name; }
            set { _mylogin.Name= value; NotifyPropertyChanged("Name"); }
        }
        public string Password
        {
            get { return _mylogin.Password; }
            set { _mylogin.Password = value; NotifyPropertyChanged("Password"); }
        }

C#

public event PropertyChangedEventHandler PropertyChanged;
       protected void NotifyPropertyChanged(string info)
       {
           if (PropertyChanged != null)
           {
               PropertyChanged(this, new PropertyChangedEventArgs(info));
           }
       }

Question: What is the easiest way to implement icommand ? . this is my first wpf example with MVVM patern . i would like to know how command works.(sorry for my poor english)

Posted 9-Mar-14 3:46am

Member 10655429

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Matt T Heffron · Answer 1 · 2014-03-10T12:17:00

Solution 2

Some good support for MVVM can be found in Josh Smith's MVVM Foundation library[^].
There is an implementation of RelayCommand and other quite useful stuff!

Posted 10-Mar-14 12:17pm

Matt T Heffron

Tomas Takac · Answer 2 · 2014-03-10T11:26:00

You definitely should do more reading. But to get you started...

You don't want your VM to implement ICommand. Commands are separate objects exposed by your VM. To avoid creating a class for each command a common implementation named DelegateCommand or RelayCommand is used. You can implement one yourself or use one which comes with a MVVM framework (e.g. Prism, some more links here). As the name suggest the command will relay the call to a delegate you provide in the constructor. Here is how it works:

C#

class LoginViewModel 
{
  ICommand MyCommand { get; private set; }

  public LoginViewModel()
  {
    MyCommand = new DelegateCommand(MyMethod);
  }

  private void MyMethod(object parameter)
  {
    // handle the call here
  }
}