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Thread: Open new window when button on main-window is clicked

  1. #1
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    Default Open new window when button on main-window is clicked

    Hi
    I am trying to create a Nokia mobile application using Qt. It has two forms/windows (for now) . Window1 is shown below:

    Fig: window1

    When I click on the first button (‘Add’) in window1, I want it to open window2 shown below:

    Fig: window2

    Both were created using Qt Designer in Qt Creator.

    Window1 is the MainWindow template and window2 is of Widget template.

    I also have the following headers and classes. When I run the application, it builds with no errors and I can see the main window but when I click on the add button I don’t see window2.
    CAN ANY ONE HELP ME IDENTIFY WHAT I AM DOING WRONG?


    Fig3: main window header file


    Fig4: main window class file

    I could not attach the window2 header and class file due to the limit on attaching images but the full project can be found here: http://www.nagorik.org/qt/WT.rar

    PLEASE HELP ME GET STARTED WITH THIS PROJECT.
    Thanks in advance for your help.

  2. #2
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    Default Re: Open new window when button on main-window is clicked

    For a start, post code in [code] tags, not as images.

    You have an Add push button in the WT Designer UI that you completely ignore: this button does nothing as a result. You then create another push button labelled Add and show it as a top-level window (look carefully when you start the application) and connect it to your slot. When you click the free-standing Add button the second form is shown.

    The second form shows overlaid in a messy fashion on the main form's content because you have given the second form the first form as parent: you probably don't want to do this if the second form is supposed to stand alone.

  3. #3
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    Default Re: Open new window when button on main-window is clicked

    Thanks Chris for your reply.
    I will certainly post code in [CODE] tags next time.

    Regarding providing a parent, how can I prevent memory leaks if I don't provide the first form as a parent.
    Some details on the concept of preventing memory leaks, in the context of multiple forms in Qt, would be very much appreciated.

    Thanks again for your help.

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    Default Re: Open new window when button on main-window is clicked

    This is just standard C++ memory management. It depends on where and how you use it. For windows that are to be short lived (e.g. modal QDialogs) then you can create them on the stack and they are automatically cleaned up as they go out of scope. If you allocate the memory on the heap with new then you must ensure that delete is called at some point. Usually the destructor of the allocating class is the correct place. Another option is to use one of the "smart" pointers: QScopedPointer or QSharedPointer.

  5. The following user says thank you to ChrisW67 for this useful post:

    SNK111 (23rd December 2010)

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