Windows窗体的C＃类耦合

Question

I am currently attempting to modify an existing Windows Forms project to better comply with SOLID principles. Currently there is a main class that initalizes the form and all the logic is then processed in a logic class.

This creates high coupling and isn't untestable because all the locic changes things on the main form. For example I have a button to refresh a grid, this calls the logic class to build the data and then this refreshes the grid. Below is a short example of how it currently looks.

public partial class XpressReports : Form
{
    private void refresh_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
    {
        try
        {
            Globals.DataLogic.RefreshData();
        }
        catch (Exception ex)
        {
            MessageBox.Show(this, ex.Message);
        }
    }
}

public class DataLogic
{
    public void RefreshData()
    {
        dataset selectedTableList;

        selectedTableList = GetNonRefreshFlagColumnIdList();

        dataGridView.Columns.Clear();
        dataGridControl.DataSource = null;
        dataGridControl.DataSource = dataViewData.Tables[0];
    }
}

Im not sure what the ideal approach for something like this would be. I could create a new method do update the datasource in the main form class but then there would still be a lot of back and forward between the two. What is the best way of seperating this kind of thing out?

Answer 1

The clearer way I have seen so far in windows forms is using a Presente pattern.

You can either call directly your presenter from the form or trigger events the preseter is subscribed to.

The presenter will keep a reference to the view(form) and will call the appropriate methods on it.

Use an interface for the view methods to decouple your presenter from your actual form.

Something like the following pseudocode:

 public interface IView 
 {
     event EventHandler Initialise;
     void SetData(MyData data)
 }

 public class Presenter
 {
    ....

     public Presenter(IView view ) 
     { 
         _view = view;
         _view.Initialise += OnViewInitialise; 
     }

     public void OnViewInitialise() 
     {
          var data = _repository.GetData();
          _view.SetData(data);
     }
 }