Question

I have created a program with Windows Forms in C# and the architecture is something like this

* BaseClass.cs
* EntityClass.cs
* ControllerClass.cs
* DataAccessClass.cs
* Viewer.cs

So basically the Entity class inherits from the base class, and the data access class goes and retrieves data from a MySql database.

What I want to do is to be able to use the data pulled without having to call the data access class if I already pulled it once.. where can I put this data so I can access it anywhere?..

I was reading about serializing into memory.. but I want to get a good advise here on where to put it and if possible how. I would really appreciate any pointers.

Regards

Answer 1

Seems like you want to continue with the MVC pattern, and introduce a “Model” component that is shared between your 2 views. The Model would be initialized/refreshed using your DataAccessClass. Each form (or View) should have a reference to the Model. I would not suggest using serialization as you are just sharing an in-memory C# object in the same process between 2 different Forms.

For example:

public class MyFirstView : Form
{    
  private ModelClass m_model;
  public MyFirstView(ModelClass model)
  {
     m_model = model;
     m_model.OnDataRefresh += this.Model_OnDataRefresh;
  }   
}

public class MySecondView : Form
{    
  private ModelClass m_model;
  public MySecondView(ModelClass model)
  {
     m_model = model;
     m_model.OnDataRefresh += this.Model_OnDataRefresh; 
  }   
}

public class ModelClass 
{
   private DataAccessClass m_dataAccess;

   public event EventHandler OnDataRefresh = {}; // fired when data is refreshed

   public void EnsureDataIsLoaded();  // queries the db if we haven't already
   public void RefreshData(); // refreshes the data from the db
   public IList<Entity> GetDataList(); // access to data items
}

For each Form/View, you can use the Form.Load event to refresh the view with the model data. Perhaps you could have a method on the ModelClass.EnsureDataIsLoaded() that will use the DataAccessClass to query the database if the you haven’t already.

And lastly, if the model changes, you need some way to push the changes to the view(s). One way to do this is have the model fire an event when the data is refreshed, and each view subscribes to that event.