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1 | class MyClass : INotifyPropertyChanged | |
2 | { | |
3 | private string _foo; | |
4 | public string Foo | |
5 | { | |
6 | get { return _foo; } | |
7 | set | |
8 | { | |
9 | _foo = value; | |
10 | - | OnPropertyChanged(() => Foo, () => Baz); |
10 | + | OnPropertyChanged(() => new { Foo, Baz }); |
11 | } | |
12 | } | |
13 | ||
14 | private int _bar; | |
15 | public int Bar | |
16 | { | |
17 | get { return _bar; } | |
18 | set | |
19 | { | |
20 | _bar = value; | |
21 | - | OnPropertyChanged(() => Bar, () => Baz); |
21 | + | OnPropertyChanged(() => new { Bar, Baz }); |
22 | } | |
23 | } | |
24 | ||
25 | public string Baz | |
26 | { | |
27 | get { return _foo + _bar; } | |
28 | } | |
29 | ||
30 | public event PropertyChangedEventHandler PropertyChanged; | |
31 | ||
32 | protected virtual void OnPropertyChanged(string propertyName) | |
33 | { | |
34 | var handler = PropertyChanged; | |
35 | if (handler != null) | |
36 | handler(this, new PropertyChangedEventArgs(propertyName)); | |
37 | } | |
38 | ||
39 | - | protected void OnPropertyChanged(params Expression<Func<object>>[] propertySelectors) |
39 | + | protected void OnPropertyChanged<T>(Expression<Func<T>> propertySelector) |
40 | { | |
41 | - | foreach (var expr in propertySelectors) |
41 | + | foreach (string name in ExtractPropertyNames(propertySelector)) |
42 | { | |
43 | - | OnPropertyChanged(ExtractPropertyName(expr)); |
43 | + | OnPropertyChanged(name); |
44 | } | |
45 | } | |
46 | ||
47 | - | protected static string ExtractPropertyName(Expression<Func<object>> propertySelector) |
47 | + | protected static string[] ExtractPropertyNames<T>(Expression<Func<T>> propertySelector) |
48 | { | |
49 | var memberExpr = propertySelector.Body as MemberExpression; | |
50 | - | if (memberExpr == null) |
50 | + | |
51 | return new[] { memberExpr.Member.Name }; | |
52 | - | // Handle boxing of value types |
52 | + | |
53 | - | var boxingExpr = propertySelector.Body as UnaryExpression; |
53 | + | // Handle anonymous type |
54 | - | if (boxingExpr != null && boxingExpr.NodeType == ExpressionType.Convert && boxingExpr.Type == typeof(object)) |
54 | + | var newExpr = propertySelector.Body as NewExpression; |
55 | if (newExpr != null) | |
56 | - | memberExpr = boxingExpr.Operand as MemberExpression; |
56 | + | |
57 | var names = new List<string>(); | |
58 | foreach (var arg in newExpr.Arguments) | |
59 | { | |
60 | - | return memberExpr.Member.Name; |
60 | + | memberExpr = arg as MemberExpression; |
61 | - | throw new ArgumentException("Only member access expressions are supported"); |
61 | + | if (arg == null) |
62 | throw new ArgumentException("Only member access expressions are supported in anonymous types"); | |
63 | names.Add(memberExpr.Member.Name); | |
64 | } | |
65 | return names.ToArray(); | |
66 | } | |
67 | ||
68 | throw new ArgumentException("Only member access expressions and anonymous type creation are supported"); | |
69 | } | |
70 | } |