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  4. [SOLVED] qcombobox and clear()
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[SOLVED] qcombobox and clear()

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  • X Offline
    X Offline
    xeroblast
    wrote on last edited by
    #13

    this is the result that the debugger catch using the above code..

    Warning: Object::connect: (sender name: 'AddItemPurchaseOrder')
    Warning: Object::connect: (receiver name: 'CreatePurchaseOrder')
    Fatal: ASSERT failure in QVector<T>::operator[]: "index out of range", file /usr/include/qt4/QtCore/qvector.h, line 346
    Scope for 20:
    Symbol type is a variable with complex or multiple locations (DWARF2), length 4.
    Symbol msg is a variable with complex or multiple locations (DWARF2), length 8.

    i tried everything as simple like inputting manual data in the qcombobox. and if there is already item/s in the combobox then an error appear... if i dont put initial item/s, it will only run correctly in the first, on second select, the error appears again..

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    • A Offline
      A Offline
      andre
      wrote on last edited by
      #14

      No, this is not the backtrace.

      You should really get the list of function calls that led to your crash.

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      • X Offline
        X Offline
        xeroblast
        wrote on last edited by
        #15

        that's what appears in the debugger.. btw, im using ubuntu..

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        • A Offline
          A Offline
          andre
          wrote on last edited by
          #16

          If you are running your app in the debugger from the commandline, issue the bt command to gdb after the crash. From QtCreator, the backtrace should pop up automatically if a crash happens in debug mode.

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          • X Offline
            X Offline
            xeroblast
            wrote on last edited by
            #17

            im sorry but there is no popup.. im using QDevelop & QtDesigner in ubuntu..

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            • A Offline
              A Offline
              andre
              wrote on last edited by
              #18

              QDevelop is not the same as QtCreator. And it is not a popup, it is part of the debug mode in that program.

              Try this, on the commandline:

              gdb path/to/your/executable

              let your application crash, and then, still on the gdb prompt:

              bt

              That should give you your stack/back trace.

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              • X Offline
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                xeroblast
                wrote on last edited by
                #19

                im sorry but the gdb /path/to/exe is not working. no program running..

                Reading symbols from /home/edril/Documents/Desktop Projects/EquiApps/bin/EquiApps...done.
                (gdb)

                cursor is always blinking..

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                • X Offline
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                  xeroblast
                  wrote on last edited by
                  #20

                  i found the problem...

                  i disconnect first the signal in the dropdownProduct before using the clear().

                  @
                  void AddItemPurchaseOrderImpl::changeCategory(QString val)
                  {
                  disconnect(dropdownProduct, SIGNAL(currentIndexChanged(QString)), this, SLOT(changeProduct(QString)));
                  bool firstrun = true;
                  dropdownProduct->clear();
                  if (val == "New Category") {
                  dropdownCategory->setEditable(true);
                  } else {
                  dropdownCategory->setEditable(false);
                  QSqlDatabase db = dbaseAddItemPO.dbConnect();
                  QVector<QMap<QString, QString> > products;
                  if (val == "Uncategorized") {
                  products = dbaseAddItemPO.getData("SELECT id, product_name FROM products WHERE category_id IS NULL");
                  } else {
                  QVector<QMap<QString, QString> > category = dbaseAddItemPO.getData("SELECT id FROM category WHERE category_name='" + val + "'");
                  products = dbaseAddItemPO.getData("SELECT id, product_name FROM products WHERE category_id='" + category[0].value("id") + "'");
                  }
                  if (products.size() != 0) {
                  for (int i=0; i < products.size(); i++) {
                  dropdownProduct->addItem(products[i].value("product_name"));
                  if (firstrun) {
                  QVector<QMap<QString, QString> > brands = dbaseAddItemPO.getData("SELECT brand_name FROM product_details WHERE products_id='" + products[i].value("id") + "'");
                  if (brands.size() != 0) {
                  for (int j=0; j < brands.size(); j++) {
                  dropdownBrand->addItem(brands[i].value("brand_name"));
                  }
                  }
                  firstrun = false;
                  }
                  }
                  }
                  dropdownProduct->addItem("New Product");
                  db.close();
                  }
                  dbaseAddItemPO.dbRemove();
                  connect(dropdownProduct, SIGNAL(currentIndexChanged(QString)), this, SLOT(changeProduct(QString)));
                  }
                  @

                  and reconnect it at the end.
                  thanx to all your replies..

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                  • A Offline
                    A Offline
                    andre
                    wrote on last edited by
                    #21

                    Glad that you found the problem, but I would really like to advice you to learn some basic debugging skills. Problems of finding why an application crashes are something every developer will have to diagnose, sooner or later. Getting and reading & understanding a backtrace is a basic tool to fix those.

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                    • F fcrochik

                      I would venture a guess that the error is not on these lines of code.

                      Most likely is something that you doing somewhere else while processing signals that get triggered by adding/removing items. For example you may have code to process when the selected item changes on the combo - clearing the combo and adding new items will probably trigger that.

                      rohit713R Offline
                      rohit713R Offline
                      rohit713
                      wrote on last edited by
                      #22

                      @fcrochik said in [SOLVED] qcombobox and clear():

                      I would venture a guess that the error is not on these lines of code.

                      Most likely is something that you doing somewhere else while processing signals that get triggered by adding/removing items. For example you may have code to process when the selected item changes on the combo - clearing the combo and adding new items will probably trigger that.

                      Yes you are right. I also facing the same problem.

                      mrjjM 1 Reply Last reply
                      0
                      • rohit713R rohit713

                        @fcrochik said in [SOLVED] qcombobox and clear():

                        I would venture a guess that the error is not on these lines of code.

                        Most likely is something that you doing somewhere else while processing signals that get triggered by adding/removing items. For example you may have code to process when the selected item changes on the combo - clearing the combo and adding new items will probably trigger that.

                        Yes you are right. I also facing the same problem.

                        mrjjM Offline
                        mrjjM Offline
                        mrjj
                        Lifetime Qt Champion
                        wrote on last edited by
                        #23

                        @rohit713
                        The debugger is your friend in that case.

                        rohit713R 1 Reply Last reply
                        3
                        • mrjjM mrjj

                          @rohit713
                          The debugger is your friend in that case.

                          rohit713R Offline
                          rohit713R Offline
                          rohit713
                          wrote on last edited by
                          #24

                          @mrjj
                          Yes I disconnect the signal and after clearing the combobox I connect the signal again, now problem is solved by doing so.

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                          2
                          • F fcrochik

                            I would venture a guess that the error is not on these lines of code.

                            Most likely is something that you doing somewhere else while processing signals that get triggered by adding/removing items. For example you may have code to process when the selected item changes on the combo - clearing the combo and adding new items will probably trigger that.

                            B Offline
                            B Offline
                            BrainabilGH
                            wrote on last edited by
                            #25
                            This post is deleted!
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                            • F fcrochik

                              I would venture a guess that the error is not on these lines of code.

                              Most likely is something that you doing somewhere else while processing signals that get triggered by adding/removing items. For example you may have code to process when the selected item changes on the combo - clearing the combo and adding new items will probably trigger that.

                              E Offline
                              E Offline
                              emad22552
                              wrote on last edited by
                              #26

                              @fcrochik thanks, you saved me!

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                              • H Offline
                                H Offline
                                Higi
                                Banned
                                wrote on last edited by
                                #27
                                This post is deleted!
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