CLOSING FORMS

airmigjr

Hi people, I've a doubt: Today I work with Java, but I started teaching C# to beginners. I created two forms, each one has a button on the middle of the form. When I click the button of the first form, the second form appears and the first form disappears. When I click the button from second form, (the one that appeared), the first form appears and the second form disappears. It's just to teach how the methods .Show() and .Hide() works. Now it's working, but I've a problem: When my software is running over Visual Studio, normally if I were, for example, working with just a form, clicking on (X) to close the app, the IDE came back to development mode. But on my app, after I show some punch of clicks to go to a form and to came back to the other, even if I had been on any of the forms (first or second), if I click to close the app, It does not happens.... I have to click Shift+Control+F5 to came back to development mode, and still doesn't happens again, the form appears, and I have to close it (again), so THEN I go to development mode... Weird.... Could someone help-me ? I'm hiding the first form, and opening the other using

Form form2 = new Form();
form2.Show();
this.Hide();

and inside the Form2:

Form form1 = new Form();
form1.Show();
this.Hide();

N a v a n e e t h

Process won't quit till the main form and all foreground threads finishes executing. If you close the Form1, it should get closed properly. Is that happening?

Best wishes, Navaneeth My blog

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airmigjr wrote:

Today I work with Java, but I started teaching C# to beginners.

I don't mean to sound negative, but I don't think you should teach C# (yet) if you still have these kind of questions. That doesn't mean you're a bad programmer, but I think you still lack the thorough .Net knowledge to teach it. I'm working with .Net for almost 10 year now (since 1.0) and I wouldn't even want to teach it.

V.
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Dave Kreskowiak

You didn't close the startup form. You closed another INSTANCE of Form1. You should not have used Show to show Form2. You should have used ShowDialog. That way, when Form2 closes, the original instance of Form1 gets control back. Though, the down-side to using this is that Form1 code blocks until Form2 closes.

Form2 form2 = new Form();
this.Hide();
form2.ShowDialog();    ' Blocks until form2 closes
this.Show();

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Dave Kreskowiak

BobJanova

This is entirely the wrong way to demonstrate Show/Hide. Multi-form UIs are difficult to get right, and coding up the example that you are using correctly will introduce a whole bunch of concepts (about main forms, the application loop and Program.cs) that are not relevant to the point. Just have a button on your main form that shows or hides the secondary one. And why are you creating a new instance each time? Such an elementary misunderstanding of objects and classes indicates that you shouldn't really be teaching people about any OO environment.

airmigjr

Very thank's Mr. Kreskowiak. You helped-me very very much!!! Thank's Again!, and Best Regards!

Jegan Thiyagesan

I totally agree with you.

Think! Don't write a line of code unless you absolutely need to.

Dave Kreskowiak

As far as teaching this class, you and your students are still screwed. You don't have the prerequisite knowledge to teach this stuff. You're just going to be guessing at how things work and the only thing worse that not knowing anything at all about what you're learning is being completely misinformed about what you're learning, and that's the path you're leading these students down.

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Dave Kreskowiak

Lost User

A windows App process will not close until the Main method exits. And you're creating a new instance of the forms on each button click. What you should ideally be doing is to create a private member of Form2 in Form1 and instantiate it in the Form1's constructor or when it is first used (and vice versa for Form2).