using keyword in C#

                            The most useful advantage of using keyword is that is it calls the Dispose() method automatically to release the resources and also automatically implements the try catch blocks for you.Here it is called a using statement.So the advantage is that we don't have to explicitly write a try-catch block and our code looks small.

MassageBox in WPF Application with MVVM

Start the visual studio and create a WPF application.

Make a ViewModelBase class and inherite the InotifyPropertyChanged interface.

Create a new method in “ViewModelBase” class for show the message like -

  public void MessageBoxShow(string message)

        {

            MessageBox.Show(message, "", MessageBoxButton.OK, MessageBoxImage.Error);

        }

After create a Helper class in helper folder name is BaseCommand and Inharite/implement the Icommand Interface.

Like-

internal class BaseCommand : ICommand

{

private readonly Action _command;

        private readonly Func<bool> _canExecute;

        public BaseCommand(Action command, Func<bool> canExecute = null)

        {

            if (command == null)

                throw new ArgumentNullException("command");

            _canExecute = canExecute;

            _command = command;

        }

        public void Execute(object parameter)

        {

            _command();

        }

        public bool CanExecute(object parameter)

        {

            if (_canExecute == null)

                return true;

            return _canExecute();

        }

        public event EventHandler CanExecuteChanged;

    }

After create a class (EmployeViewModel) in ViewModel  folder and inherite the “ViewModelBase” class and add namespace  the Basecommand class.

Like-

using WPF_MVVM_MessageBox.Helper;

Create a private method in “EmployeViewModel” class for save the data and call the MessageBoxShow method.

private void Save()

        {

           

//here code for Save the Data

            MessageBoxShow("Data Save Successfully.");

        }

Create a Icommand  type property in “EmployeViewModel” class and add the Save method for Execute

Like-

public ICommand ClickCommand { get { return new BaseCommand(Save); } }

Finally add the reference of ViewModel directory in XAML window.

Like-

xmlns:me="clr-namespace:WPF_MVVM_MessageBox.ViewModels" Title="Create Employee" Height="400" Width="400"

After create a Window resource in XAML file.

Like-

<Window.Resources>

        <me:EmployeeViewModel x:Key="viewModel" />

</Window.Resources>

Add a button in XAML file.

Like-

<Button Height="50" Width="100"  Content="Click Me" Name="btnnew" Command="{Binding Source={StaticResource viewModel}, Path= ClickCommand}" />

and bind the button command to “ClickCommand” property.

Finally Run the Application and click on button

cheer.