Button disbale and enable PassowrdBox Using MVVM

Question

How to disable q button if a password box is not filled? Let's say if username and password fields are empty button should be disable as fill both fields username and password then button should be enable.

Answer 1

Just bind the IsEnabled property of the Button and use the bound property getter to determine if true or false. For example:

XAML

<Button IsEnabled="{Binding IsUsernameAndPasswordValid }"/>

C#

public partial class exampleWindow : Window 
{
     public exampleWindow () 
     {
          InitializeComponent();
          DataContext = this;      
     }

     public bool IsUsernameAndPasswordValid
     {
         get { return (String.IsNullOrEmpty(UsernameText) && String.IsNullOrEmpty(PasswordText)) ; }
     }
}

And dont forget to set the data context