Controlling many forms at the same time

Question

Suppose, I have the following task.

There is a main application form with numerous buttons; when you click on each of these buttons, you get one more form. The second click on the button should close the opened form.

These forms should not be shown in taskbar, because they are auxiliary. They should not be dialog, because that will block the main application form and prevent user from performing some other operations with the main window or with other forms like the one that is opened. They should be shown above the main form, but not above other windows (so TopMost doesn't suite). When such forms are closed, the main form should be notified, and when the main form is minimized, they should be minimized as well.

How would you solve this problem?

The current solution is based on using hooks. It's not very easy to understand and very difficult to maintain (mainly because I am not experienced in win32). It works fine for about 90% of situations, but in 10% it doesn't.

Maybe, the requirements to forms behavior are to strict?

Answer 1

Here's how most of your requirements can be accomplished:

• Set the Owner of each child Form to be the Main Form.

MSDN Quote:

When a form is owned by another form, it is closed or hidden with the owner form. For example, consider a form named Form2 that is owned by a form named Form1. If Form1 is closed or minimized, Form2 is also closed or hidden. Owned forms are also never displayed behind their owner form. You can use owned forms for windows such as find and replace windows, which should not disappear when the owner form is selected. To determine the forms that are owned by a parent form, use the OwnedForms property.

• For stoping a form from appearing in task bar you need to set the ShowInTaskBar property

Answer 2

I would recomment using some window-manager, so each button will tell the window-manager to toggle visibility of form X, if X is not there it will be shown, if it is, it will be closed. You should be able to configure the windows such that they will not show up in the taskbar. For the visibility, I am not sure what you mean. When you open a form via a button, it will usually go to front, which should be ok. If you switch the window then, what do you expect? Should the main window always stay in the background or is it allowed to come to the front when focused? Whenever I have seen applications change such standard behaviors, they failed in some way. Either wrong windows showed up or some were not accessible anymore or the user was just confused because these windows didn't act like all other windows.

Answer 3

It's not a problem. Use the Show(owner) overload to display the form.

An owned form is always on top of its owner. It minimizes automatically when you minimize the main window. No need for ShowInTaskbar. Another window model supported by winforms is MDI, check out the MdiParent property. The child windows are confined inside the bounds of the main window. Also consider using UserControls instead of a form, you can swap them in and out as needed. Or a tabbed interface, using TabControl. Weifenluo's DockPanel suite is a very popular implementation of the Visual Studio style windowing model, supporting windows that can be docked and floating within the main window. Plenty of choices here :)