How do you access a form's controls using MVP

Question

Hopefully this image is readable on here...

This is my first project implementing MVP. I've got three classes. My main form, aptly named FrmMain, FrmMainPresenter, and then MainOps which has some extra stuff.

On FrmMain, I've got a reference to FrmMainPresenter, and on FrmMainPresenter I have a reference to FrmMain.

An event on FrmMain calls a method on FrmMainPresenter.

FrmMainPresenter is supposed to get a control from the FrmMain reference and call a method on MainOps that accepts a GridControl and Collection<Control>.

However, upon trying to access the appropriate Grid and Collection within FrmMainPresenter, it tells me FrmMain doesn't contain a definition for those controls

Code on FrmMain:

    private void genericCheckbox_CheckedChanged(object sender, EventArgs e)
    {
        _presenter.CheckBoxCheckedChanged();
    }

Code on FrmMainPresenter:

    public void CheckBoxCheckedChanged()
    {
        if (!_view.SuppressCheckedChanged)
            _mo.UpdateFilter(_view.gdcSVNDefaultView, _view.Controls);
    }

Not sure what I'm doing incorrectly. I didn't think this was correct, but my only guess was to go and set the necessary controls to public in the Designer file, but that didn't work. Same results.

I guess the issue is because the interface for my form doesn't have the gridview / controls collection defined, my presenter class can't see it. But even then I'm not sure how I'd properly define it in the interface so that I could implement it on the form.

Answer 1

You can either make the Control in FrmMain public through the designer properties or add a public getter to the FrmMain code which the FrmMainPresenter can then access.

There are probably another half dozen ways this can be ultimately achieved but these are probably the 2 most common and easiest ways to do achieve your goal.