Is there a way in C# to turn the property into a string containing it's name?

Question

I'd like to get a string representation given a property. This way I can use this string for NotifyPropertyChanged and stil be ok after a refactoring of the property's name.

EDIT: I'm using .NET 4.0

UPDATE: I'd also like to have the name available for DependencyProprtys, i.e. I need the value during static variable assignment time.

Same sample code to explain:

// actual code

private int prop = 42;
public int Prop
{
    get
    {
        return prop;
    }
    set
    {
        prop = value;
        NotifyPropertyChanged("Prop"); // I'd like to replace the hard-coded string here
    }
}


// code as I'd like it to be

private int propNew = 42;
private static readonly string PropNewName = GainStringFromPropertySomeHow(PropNew); // should be "PropNew"
public int PropNew
{
    get
    {
        return propNew;
    }
    set
    {
        propNew = value;
        NotifyPropertyChanged(PropNewName); // <== will remain correct even if PropNew name is changed
    }
}

After refactoring:

private int prop = 42;
public int PropNameChanged
{
    get
    {
        return prop;
    }
    set
    {
        prop = value;
        NotifyPropertyChanged("Prop"); // oops
    }
}


private int propNew = 42;
private static readonly string PropNewName = GainStringFromPropertySomeHow(PropNewNameChanged); // should be "PropNewNameChanged"
public int PropNewNameChanged
{
    get
    {
        return propNew;
    }
    set
    {
        propNew = value;
        NotifyPropertyChanged(PropNewName); // still correct
    }
}

score 1 · Answer 1 · answered Aug 01 '13 at 08:54

I think this could be helpfull:

// This method is called by the Set accessor of each property.
// The CallerMemberName attribute that is applied to the optional propertyName
// parameter causes the property name of the caller to be substituted as an argument.
private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
{
if (PropertyChanged != null)
{
    PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}

Source and more explanation: http://msdn.microsoft.com/de-de/library/system.componentmodel.inotifypropertychanged.aspx

And here: http://msdn.microsoft.com/de-de/library/system.runtime.compilerservices.callermembernameattribute.aspx

Would be a nice solution, but I'm using .NET 4.0. – Onur Aug 01 '13 at 09:12 — Onur, Aug 01 '13 at 09:12

score 1 · Answer 2 · edited May 23 '17 at 12:05

1

If you're not yet on .Net 4.5 and thus cannot use CallerMemberName, you can use this approach: https://stackoverflow.com/a/3191598/869250

edited May 23 '17 at 12:05

Community

1
1

answered Aug 01 '13 at 09:04

Daniel Sklenitzka

2,116
1
17
25

Looks similar to the solution I found in another answer. – Onur Aug 01 '13 at 09:11

score 1 · Answer 3 · edited May 23 '17 at 12:05

1

This is a duplicate of How to get current property name via reflection?

So you can just do this

NotifyPropertyChanged(MethodBase.GetCurrentMethod().Name);

edited May 23 '17 at 12:05

Community

1
1

answered Aug 01 '13 at 09:05

Mirsha

118
5

score 0 · Answer 4 · edited May 23 '17 at 12:11

I found a solution here on Stackoverflow:

https://stackoverflow.com/a/672212/1254743

and

https://stackoverflow.com/a/2820759/1254743

The resulting code:

public static class PropertyNameExtractor
{
    /// <summary>
    /// Usage: PropertyNameExtractor.ExposeProperty(() => this.YourProperty)
    /// yields: "YourProperty"
    /// </summary>
    public static string ExposeProperty<T>(Expression<Func<T>> property)
    {
        var expression = GetMemberInfo(property);
        return expression.Member.Name;

    }

    private static MemberExpression GetMemberInfo(Expression method)
    {
        LambdaExpression lambda = method as LambdaExpression;
        if (lambda == null)
            throw new ArgumentNullException("method");

        MemberExpression memberExpr = null;

        if (lambda.Body.NodeType == ExpressionType.Convert)
        {
            memberExpr =
                ((UnaryExpression)lambda.Body).Operand as MemberExpression;
        }
        else if (lambda.Body.NodeType == ExpressionType.MemberAccess)
        {
            memberExpr = lambda.Body as MemberExpression;
        }

        if (memberExpr == null)
            throw new ArgumentException("method");

        return memberExpr;
    }

}

In my class:

class MyClass: INotifyPropertyChanged
{
    public MyClass()
    {
        this.nameOf_MyProperty = PropertyNameExtractor.ExposeProperty(() => this.MyProperty);

    }


    private readonly string nameOf_MyProperty;
    private int myProperty = 42 ;
    public int MyProperty
    {
        get
        {
            return myProperty;
        }
        set
        {
            myProperty= value;
            NotifyPropertyChanged(nameOf_MyProperty);
        }
    }

    private void NotifyPropertyChanged(String PropertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(PropertyName));
        }
    }
}

Is there a way in C# to turn the property into a string containing it's name?

4 Answers4