How to: create a Bars UI using the MVVM design pattern

  • 5 minutes to read

This example shows how to create three bars (File, Edit and StatusBar) using the MainMenuControl, ToolBarControl and StatusBarControl controls. In this example, the BarContainerControl is used to activate the Drag & Drop functionality for bars. Actions for bar elements are defined by commands implemented in the MyViewModel class.   The window's DataContext is set to a MyViewModel class descendant, which is automatically generated by the DevExpress.Mvvm.POCO.ViewModelSource object. This descendant automatically generates commands for all public methods in the MyViewModel class (the OpenFileCommand, NewFileCommand and SetAlignmentCommand are generated).

The result is shown below:

HowToCreateBars

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using DevExpress.Mvvm;
using DevExpress.Mvvm.UI;
using DevExpress.Mvvm.DataAnnotations;

namespace WpfApplication2 {
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window {
        public MainWindow() {
            InitializeComponent();
        }
    }


    public class MyViewModel {
        public virtual bool IsBold { get; set; }
        public virtual bool IsItalic { get; set; }
        public virtual bool IsUnderline { get; set; }
        public virtual FontWeight Weight { get; set; }
        public virtual TextDecorationCollection Decorations { get; set; }
        public virtual FontStyle Style { get; set; }                
        public virtual TextAlignment Alignment { get; set; }
        public virtual string Text { get; set; }

        public void OnIsBoldChanged() {
            Weight = IsBold ? FontWeights.Bold : FontWeights.Normal;
        }
        public void OnIsItalicChanged() {
            Style = IsItalic ? FontStyles.Italic : FontStyles.Normal;
        }
        public void OnIsUnderlineChanged() {
            Decorations = IsUnderline ? TextDecorations.Underline : new TextDecorationCollection();
        }        

        public MyViewModel() {
            Alignment = TextAlignment.Left;
            SetDefaultText();
        }

        void SetDefaultText() {
            Text = "Text";
        }

        // An OpenFileCommand will be generated from the following method by POCO.
        public void OpenFile() {
            SetDefaultText();
        }
        // A NewFileCommand will be generated from the following methods by POCO.
        public bool CanNewFile() {
            return true;
        }
        public void NewFile() {
            Text = null;
        }
        // A SetAlignmentCommand will be generated from the following method by POCO.
        public void SetAlignment(object parameter) {
            Alignment = ((TextAlignment)parameter);
        }

    }    
}