Latest news for how to buy viagra

Average Rating: 4.8 out of 5 based on 177 user reviews.

I'm not going to delve into the definition of , but you'll see how it's implemented, and how I found it can help me with implementing . Now, I've never been a fan of INotifyPropertyChanged myself, mostly because it feels wet (read: not DRY).   I'm working on a WPF app at the moment, and have come to realize, if I embrace INotifyPropertyChanged, I get to take full advantage of the excellent WPF databinding story. Here is what a normal use of INotifyPropertyChanged looks like:

    public class Person : INotifyPropertyChanged
    {
        private string _firstName;
        private string _lastName;

        public event PropertyChangedEventHandler PropertyChanged;

        public string FirstName
        {
            get { return _firstName; }
            set
            {
                if (_firstName != value)
                {
                    _firstName = value;
                    FirePropertyChanged("FirstName");
                }
            }
        }

        public string LastName
        {
            get { return _lastName; }
            set
            {
                if (_lastName != value)
                {
                    _lastName = value;
                    FirePropertyChanged("LastName");
                }
            }
        }

        private void FirePropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this,  new PropertyChangedEventArgs(propertyName));
            }
        }
    }
Here is what the static reflection use of INotifyPropertyChanged looks like:
    public class PersonStaticReflection : NotifyPropertyChanged
    {
        private string _firstName;
        private string _lastName;

        public string FirstName
        {
            get { return _firstName; }
            set { SetProperty(()=> FirstName,  ()=> _firstName,  value); }
        }

        public string LastName
        {
            get { return _lastName; }
            set
            {
                SetProperty( () => LastName,  () => _lastName,  value,  () =>
                   {
                       // do something useful here
                   });
            }
        }
    }
Doesn't that just feel DRYer?  It does to me! There are several important pieces to note:
  • Inheriting from NotifyPropertyChanged, this is the class that holds the SetProperty method, and hides the static reflection magic.
  • We're calling SetProperty with three arguments in the FirstName property
    • first: a LINQ Expression pointing to the property we're changing
    • second: a LINQ [how to buy viagra] Expression pointing to the field to backing the property
    • third: the new, incoming value
  • We're calling SetProperty with a fourth argument in the LastName property
    • fourth: an action that will get executed only if the values were different
  • The SetProperty method, is going to look at the current value of the field, and the incoming value.   If the two are different, it will assign the new value to the field, and then fire the NotifyPropertyChanged event how to buy viagra, with the name of the property given via the first argument.   I ended up pulling this into its own class so I could use it as the in my View Model layer. Here is the implementation:
    public class NotifyPropertyChanged : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        protected void SetProperty < T>( Expression < Func<T>> propExpr,  Expression<Func<T>> fieldExpr,  T value )
        {
            SetProperty(propExpr,  fieldExpr,  value,  ()=> { });
        }

        protected void SetProperty < T>( Expression < Func<T>> propExpr,  Expression < Func < T>> fieldExpr,  T value,  Action doIfChanged )
        {
            var prop = (PropertyInfo)((MemberExpression)propExpr. Body). How to buy viagra member;
            var field = (fieldinfo)((memberexpression)fieldexpr. Body). Member;

    how to buy viagra         var currVal = prop. GetValue( this,  null );

            if( currVal == null && value == null )
                return;
            if( currVal == null || !currVal. Equals( value ) )
            {
                field. SetValue( this,  value );
                doIfChanged();

                if( PropertyChanged != null )
                    PropertyChanged( this,  new PropertyChangedEventArgs( prop. Name ) );
            }
        }
    }
Questions/comments/likes/dislikes? Let me know.


?? 2008-2016 Legit Express Chemist.