Question

In a parent form A, there’s the following code to call a child form “B”:

        Window frmChildB;
        frmChildB = new FormB();
        frmChildB.ShowDialog();

In the same form: the following code to call a child form “C”:

        Window frmChildC;
        frmChildC = new FormC();
        frmChildC.ShowDialog();

Now I want to make a button in form B, so that if I click that button, it automatically navigate to form C.

Using a reference object of form C in form B like in the answer of this question should be avoided if possible. The reason is that there are more than ten forms like B, C… and each of them must be able to navigate to another. Having 10 form-referenced objects inside a form isn’t good.

I think there must be some way to achieve the effect. Does anyone know about this?

Answer 1

If I understand your question correctly, you would like to have a single instance of each of the forms and just navigate back and forth between them.

If this is what you want, you can implement a static FormManager class that creates instances of the forms and shows them as needed. You can even use an enum to further reduce the complexity.

Here is an example of this class (it will need some additional work, but should give you a good idea):

public class FormManager
{
    private static FormB m_FormB;
    public static FormB formB
    {
        get
        {
            if (m_FormB == null)
            {
                m_FormB = new FormB();
            }
            return m_FormB;
        }
    }
    private static FormC m_FormC;
    puClic static FormC formC
    {
        get
        {
            if (m_FormC == null)
            {
                m_FormC = new FormC();
            }
            return m_FormC;
        }
    }

    public enum FormId
    {
        FormB,
        FormC
    }

    public static Form ShowForm(FormId whichForm)
    {
        Form oForm;

        switch (whichForm)
        {
            case FormId.FormB:
                oForm = FormManager.formB;
                break;

            case FormId.FormC:
                oForm = FormManager.formC;
                break;

            default:
                oForm = null;
                break;
        }

        if (oForm != null)
        {
            oForm.ShowDialog();
        }
        return oForm;
    }
}

This can be called from the child forms as:

FormManager.ShowForm(FormManager.FormId.FormB);