Form Navigation in Win CE 5 Application

Question

I'm Trying to develop an app for an old handheld device running .Net 3.5 Win CE 5 however I cannot seem to get over a basic hurdle switching forms!!

I started using

Application.Run(new frm_class());

but this started crashing after opening any more then 2 forms.

I then tried.

this.hide();
frm_class frm = new frm_class();
frm.show();

then just ended up being a constant loop of loading the form then I seen someone wrote a very simple class to handle this.

    public static void switchForm(Form newForm, Form oldform)
    {
        newForm.Show();
        oldform.Hide();
        oldform.Dispose();
    } 

call via

    frm_class frm = new frm_class();
    switchform(frm,this);

which shuts the app down when loading the second form.

This seems so stupid but I cannot find out a way of just navigating through simple forms ie close this form then open this one or vice versa!!

can anyone help?

Answer 1

Application.Run(new frm_class()); will start a message loop and makes the specified form visible and waits untill it is closed. Once the specified form closes, the message loop terminates. oldform.Dispose(); will dispose (and close) the form, not hide it.

Your second solution seems like the one you should take, which shouldn't loop. Make sure the code isn't in the constructor or form_load event if you're creating the same form again. Can you post the code surrounding this?

You could also remove the new frm_class() argument from Application.Run(). Which will create a constant running message loop. Just don't forget to call Application.Exit() at some point.

You should make sure the form is made visible before the parameterless Application.Run() because the execution inside this codeblock wont continue untill Application.Exit() is called from inside your form.

frm_class frm = new frm_class();
frm.Show();
Application.Run();

// Some button or event inside the form should be executing the exit call:
Application.Exit();