What is the importance of RaisePropertyChanged?
.net, c#, mvvm, mvvm-light
Solution
Read this:
http://msdn.microsoft.com/en-us/library/system.componentmodel.inotifypropertychanged.aspx
The `RaisePropertyChanging` event is used to notify UI or bound elements that the data has changed. For example a `TextBox` needs to receive a notification when the underlying data changes, so that it can update the text you see in the UI. Without the `NotifyPropertyChanged` event, the `TextBox` would have no idea that the data changed.
It's very important in MVVM.
Problem
I am currently learning MVVM and i don't understand how `RaisePropertyChanged` is important For example this function : ``` public City SelectedCity { get { return selectedcity; } set { RaisePropertyChanging(SelectedCityLocationPropertyName); selectedtrend = value; RaisePropertyChanged(SelectedCityLocationPropertyName); MessageBox.Show(City.Name); } } ``` and this one : ``` public City SelectedCity { get { return selectedcity; } set { // RaisePropertyChanging(SelectedCityLocationPropertyName); selectedtrend = value; // RaisePropertyChanged(SelectedCityLocationPropertyName); MessageBox.Show(City.Name); } } ``` Give exactly the same result for me. Can you please tell me why is `RaisePropertyChanged` so important and give me an example where it would make a vital difference?