「ベスト プラクティス」のアプローチは、ビューモデルでモデルを装飾し、必要に応じてモデル プロパティを公開することです。おそらくプロパティマッピングなどを使用して、動的オブジェクトを使用した気の利いた作業で汎用ViewModelを作成できます。
public class DynamicViewModel : DynamicObject, INotifyPropertyChanged, IDisposable
{
public event PropertyChangedEventHandler PropertyChanged;
private static readonly Dictionary<Type, Tuple<Dictionary<string, PropertyInfo>, Dictionary<string, string>>> typeDictionary = new Dictionary<Type, Tuple<Dictionary<string, PropertyInfo>, Dictionary<string, string>>>();
private readonly Dictionary<string, object> additionalProperties = new Dictionary<string, object>();
private readonly object underlyingObject;
public object UnderlyingObject
{
get
{
return underlyingObject;
}
}
private readonly Type type;
/// <summary>
/// constructor which takes a model for which it will be extensing its perceived properties
/// </summary>
/// <param name="underlyingObject">the underlying object</param>
public DynamicViewModel(IBindableRfqViewModel underlyingObject) : this(underlyingObject, new Dictionary<string, string>())
{
}
/// <summary>
/// constructor which takes a model for which it will be extensing its perceived properties as well as a property map
/// </summary>
/// <param name="underlyingObject">the underlying object</param>
/// <param name="propertyMap">a string/string dictionary, where the key is a property on the underlying object, and the value is the name of the dynamic property to be used as a binding target</param>
public DynamicViewModel(IBindableRfqViewModel underlyingObject, Dictionary<string, string> propertyMap)
{
this.underlyingObject = underlyingObject;
if (underlyingObject is INotifyPropertyChanged)
{
((INotifyPropertyChanged)underlyingObject).PropertyChanged += OnUnderlyingPropertyChanged;
}
type = underlyingObject.GetType();
if (typeDictionary.ContainsKey(type))
{
return;
}
lock (typeDictionary)
{
if (typeDictionary.ContainsKey(type))
{
return;
}
var forwardPropertyMap = propertyMap;
var typeProperties = type.GetProperties(BindingFlags.Public | BindingFlags.Instance).ToDictionary(p => p.Name, p => p);
typeDictionary.Add(type, Tuple.Create(typeProperties,forwardPropertyMap));
}
}
private void OnUnderlyingPropertyChanged(object sender, PropertyChangedEventArgs e)
{
this.OnPropertyChanged(e.PropertyName);
}
private bool TryGetProperty(string name, out object result)
{
try
{
var propertyData = typeDictionary[type];
var modelProperty = name;
if (propertyData.Item2.ContainsKey(name))
{
modelProperty = propertyData.Item2[name];
}
if (propertyData.Item1.ContainsKey(modelProperty))
{
result = propertyData.Item1[modelProperty].GetValue(underlyingObject, null);
return true;
}
if (additionalProperties.ContainsKey(name))
{
result = additionalProperties[name];
return true;
}
result = null;
return true;
}
catch (Exception ex)
{
result = null;
return false;
}
}
/// <summary>
/// <see cref="DynamicObject.TryGetMember" />
/// </summary>
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
return this.TryGetProperty(binder.Name, out result);
}
/// <summary>
/// <see cref="DynamicObject.TryGetIndex" />
/// </summary>
public override bool TryGetIndex(GetIndexBinder binder, object[] indexes, out object result)
{
return this.TryGetProperty(indexes[0].ToString(), out result);
}
private bool TrySetProperty(string name, object value)
{
try
{
var propertyData = typeDictionary[type];
var modelProperty = name;
if (propertyData.Item2.ContainsKey(name))
{
modelProperty = propertyData.Item2[name];
}
if (propertyData.Item1.ContainsKey(modelProperty))
{
propertyData.Item1[modelProperty].SetValue(underlyingObject, value, null);
}
else
{
if (!additionalProperties.ContainsKey(name))
{
additionalProperties.Add(name, new object());
}
additionalProperties[name] = value;
}
this.OnPropertyChanged(name);
return true;
}
catch (Exception ex)
{
return false;
}
}
/// <summary>
/// <see cref="DynamicObject.TrySetMember" />
/// </summary>
public override bool TrySetMember(SetMemberBinder binder, object value)
{
return this.TrySetProperty(binder.Name, value);
}
/// <summary>
/// <see cref="DynamicObject.TrySetIndex" />
/// </summary>
public override bool TrySetIndex(SetIndexBinder binder, object[] indexes, object value)
{
return indexes.Length == 0 || this.TrySetProperty(indexes[0].ToString(), value);
}
private void OnPropertyChanged(string propName)
{
var handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propName));
}
}
/// <summary>
/// IDisposable implementation
/// </summary>
public void Dispose()
{
if (underlyingObject is INotifyPropertyChanged)
{
((INotifyPropertyChanged)underlyingObject).PropertyChanged -= OnUnderlyingPropertyChanged;
}
if (underlyingObject is IDisposable)
{
((IDisposable)underlyingObject).Dispose();
}
}
}