MVVM Implementing started

SewerStammGen/ViewModel/ViewModel.cs

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+using Syncfusion.UI.Xaml.Collections.Generic;
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Linq;
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace SewerStammGen.ViewModel
+{
+    [Serializable]
+    public abstract class ViewModel : IViewModel
+    {
+        protected ViewModel()
+        {
+            var initializationTask = new Task(() => Initialize());
+            initializationTask.ContinueWith(result => InitializationCompletedCallback(result));
+            initializationTask.Start();
+        }
+
+
+        /// <summary>
+        /// Initializes this instance.
+        /// </summary>
+        protected virtual void Initialize()
+        {
+        }
+
+
+        /// <summary>
+        /// Callback method for the async initialization.
+        /// </summary>
+        /// <param name="result">The result.</param>
+        private void InitializationCompletedCallback(IAsyncResult result)
+        {
+            var initializationCompleted = InitializationCompleted;
+            if (initializationCompleted != null)
+            {
+                InitializationCompleted(this, new AsyncCompletedEventArgs(null, !result.IsCompleted, result.AsyncState));
+            }
+            InitializationCompleted = null;
+        }
+
+        /// <summary>
+        /// Occurs when the initialization is completed.
+        /// </summary>
+        public event AsyncCompletedEventHandler InitializationCompleted;
+
+        /// <summary>
+        /// Called when a property has changed.
+        /// </summary>
+        /// <param name="propertyName">Name of the property.</param>
+        /// <remarks></remarks>
+        protected virtual void OnPropertyChanged([CallerMemberName]string propertyName = "")
+        {
+            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
+        }
+
+        #region INotifyPropertyChanged Members
+
+        /// <summary>
+        /// Occurs when a property value changes.
+        /// </summary>
+        /// <remarks></remarks>
+        public event PropertyChangedEventHandler PropertyChanged;
+
+        #endregion
+    }
+
+    public abstract class ViewModel<TModel> : ViewModel, IViewModel<TModel> where TModel : class
+    {
+        private TModel model;
+
+        /// <summary>
+        /// The Model encapsulated by this ViewModel.
+        /// </summary>
+        /// <remarks>If you change this, all needed PropertyChanged events will be raised automatically.</remarks>
+        [Browsable(false)]
+        [Bindable(false)]
+        public TModel Model
+        {
+            get
+            {
+                return model;
+            }
+            set
+            {
+                if (Model != value)
+                {
+                    // get all properties
+                    var properties = this.GetType().GetProperties(BindingFlags.Public);
+                    // all values before the model has changed
+                    var oldValues = properties.Select(p => p.GetValue(this, null));
+                    var enumerator = oldValues.GetEnumerator();
+
+                    model = value;
+
+                    // call OnPropertyChanged for all changed properties
+                    foreach (var property in properties)
+                    {
+                        enumerator.MoveNext();
+                        var oldValue = enumerator.Current;
+                        var newValue = property.GetValue(this, null);
+
+                        if ((oldValue == null && newValue != null)
+                            || (oldValue != null && newValue == null)
+                            || (!oldValue.Equals(newValue)))
+                        {
+                            OnPropertyChanged(property.Name);
+                        }
+                    }
+                }
+            }
+        }
+
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ViewModel"/> class.
+        /// </summary>
+        /// <remarks></remarks>
+        protected ViewModel(TModel model)
+            : base()
+        {
+            this.Model = model;
+        }
+
+        /// <summary>
+        /// Returns a hash code for this instance.
+        /// </summary>
+        /// <returns>
+        /// A hash code for this instance, suitable for use in hashing algorithms and data structures like a hash table. 
+        /// </returns>
+        public override int GetHashCode()
+        {
+            return Model.GetHashCode();
+        }
+
+        /// <summary>
+        /// Determines whether the specified <see cref="System.Object"/> is equal to this instance.
+        /// </summary>
+        /// <param name="obj">The <see cref="System.Object"/> to compare with this instance.</param>
+        /// <returns>
+        ///   <c>true</c> if the specified <see cref="System.Object"/> is equal to this instance; otherwise, <c>false</c>.
+        /// </returns>
+        public override bool Equals(object obj)
+        {
+            if (obj == null)
+                return false;
+
+            var other = obj as IViewModel<TModel>;
+
+            if (other == null)
+                return false;
+
+            return Equals(other);
+        }
+
+
+        /// <summary>
+        /// Determines whether the specified <see cref="IViewModel<TModel>"/> is equal to this instance.
+        /// </summary>
+        /// <param name="other">The <see cref="IViewModel<TModel>"/> to compare with this instance.</param>
+        /// <returns>
+        ///   <c>true</c> if the specified <see cref="IViewModel<TModel>"/> is equal to this instance; otherwise, <c>false</c>.
+        /// </returns>
+        public bool Equals(IViewModel<TModel> other)
+        {
+            if (other == null)
+                return false;
+
+            if (Model == null)
+                return Model == other.Model;
+
+            return Model.Equals(other.Model);
+        }
+    }
+}