I created a method in C# to get methodname
public string GetCorrectPropertyName<T>(Expression<Func<T, string>> expression)
{
return ((MemberExpression)expression.Body).Member.Name; // Failure Point
}
and calling it as
string lcl_name = false;
public string Name
{
get { return lcl_name ; }
set
{
lcl_name = value;
OnPropertyChanged(GetCorrectPropertyName<ThisClassName>(x => x.Name));
}
}
This works fine if property is string and for all other types gives this exception:
Unable to cast object of type 'System.Linq.Expressions.UnaryExpression' to type 'System.Linq.Expressions.MemberExpression'.
x => x.PropertyName
to x => Convert.ToString(x.PropertyName)
and it still failsWhere am I wrong?
You need a separate line to extract the Member where the input expression is a Unary Expression.
Just converted this from VB.Net, so might be slightly off - let me know if I need to make any minor tweaks:
public string GetCorrectPropertyName<T>(Expression<Func<T, Object>> expression)
{
if (expression.Body is MemberExpression) {
return ((MemberExpression)expression.Body).Member.Name;
}
else {
var op = ((UnaryExpression)expression.Body).Operand;
return ((MemberExpression)op).Member.Name;
}
}
The VB version is:
Public Shared Function GetCorrectPropertyName(Of T) _
(ByVal expression As Expression(Of Func(Of T, Object))) As String
If TypeOf expression.Body Is MemberExpression Then
Return DirectCast(expression.Body, MemberExpression).Member.Name
Else
Dim op = (CType(expression.Body, UnaryExpression).Operand)
Return DirectCast(op, MemberExpression).Member.Name
End If
End Function
Note that the input expression does not return string necessarily - that constrains you to only reading properties that return strings.