WPF MVVM CommonServiceLocator v2.0.4

Question

Hi everyone,

 

I have a project on WPF MVVM, .net framework 4. After some requestes I had to upgrade the framework to 4.5, and also change some libraries like microsoft.practices.servicelocation, which then changed to CommonServiceLocator. 

 

Following this upgrade, a part of my code does not work as it used to. More specifically, I have a textbox with a button next to it. If the textbox is empty then the button is disabled. When you type in textbox then the button then is enabled. With previous library, microsoft.practices.servicelocation, the boolean method that I had in relaycommand called everytime and when textbox length > 0 then the button was enabled. After the upgrade this method called only on viewmodel load and when I type in textboxnothing happens. 

 

I will really appreciate if someone can help me to solve this problem. I am not experienced on WPF MVVVM and I have spent many hours to find any solution without success.