Results 1 to 5 of 5

Thread: QComboBox Problem

  1. 19th January 2012, 03:52 #1
    anouar2002
    anouar2002 is offline Novice
    Join Date
    Jan 2012
    Posts
    25
    Thanks
    10
    Qt products
    Qt4
    Platforms
    Windows

    Default QComboBox Problem

    Hello!
    How to choose what is the value of QComboBox which I want to be displayed in the loading of the interface.
    I read the documentation and I found this method "setItemText (int index, QString text)" as I used to index 0 for the value to be displayed first but it result nothing.
    What should I do? Thank you in advance
    NB: the values ​​of my QComboBox are loaded from a database.
    Reply With Quote Reply With Quote
  2. 19th January 2012, 05:51 #2
    monst
    monst is offline Beginner
    Join Date
    Jan 2012
    Location
    St. Petersburg, Russia
    Posts
    14
    Thanks
    3
    Thanked 2 Times in 2 Posts
    Qt products
    Qt4
    Platforms
    Unix/X11 Windows
    Wiki edits
    1

    Default Re: QComboBox Problem

    Do you want to set another current item?
    Use
    Qt Code: 
    1. void setCurrentIndex(int index)
    To copy to clipboard, switch view to plain text mode 
    .
    Reply With Quote Reply With Quote
  3. 19th January 2012, 15:14 #3
    anouar2002
    anouar2002 is offline Novice
    Join Date
    Jan 2012
    Posts
    25
    Thanks
    10
    Qt products
    Qt4
    Platforms
    Windows

    Default Re: QComboBox Problem

    Thank you for your response.
    The problem is that my comboBox is bound by one slot to another comboBox_Global ie when I change the value of my ComboxBox_Global, the value of comboBox is not changed
    As if there is no synchronization between them.
    This is the code:
    Qt Code: 
    1. this->model = new QSqlQueryModel();
    2.            model->setQuery("SELECT  Nom FROM Projet.dbo.Produit");
    3.            ui->comboBox->setModel(model);
    4. this->model2 = new QSqlQueryModel();
    5.                   model2->setQuery("SELECT DISTINCT N_Four FROM Projet.dbo.Produit");
    6.                   ui->comboBox_2->setModel(model2);
    7.  
    8.  
    9.                   QSqlQuery query5;
    10.                   query5.prepare("SELECT  N_Four FROM Projet.dbo.Produit WHERE Nom=:nom");
    11.                   query5.bindValue(":nom", ui->comboBox->currentText());
    12.                   if (query5.exec() && query5.next()) {
    13.                       ui->comboBox_2->setItemText(0,query5.value(0).toString());
    14.  
    15.                   }
    16. void fiche_article::on_comboBox_currentIndexChanged(const QString &arg1)
    17. {
    18.  
    19.  
    20.     QSqlQuery query5;
    21.     query5.prepare("SELECT  N_Four FROM Projet.dbo.Produit WHERE Nom=:nom");
    22.     query5.bindValue(":nom", ui->comboBox->currentText());
    23.     if (query5.exec() && query5.next()) {
    24.         ui->comboBox_2->setItemText(0,query5.value(0).toString());
    25.  
    26.     }
    To copy to clipboard, switch view to plain text mode 
    Reply With Quote Reply With Quote
  4. 19th January 2012, 20:58 #4
    monst
    monst is offline Beginner
    Join Date
    Jan 2012
    Location
    St. Petersburg, Russia
    Posts
    14
    Thanks
    3
    Thanked 2 Times in 2 Posts
    Qt products
    Qt4
    Platforms
    Unix/X11 Windows
    Wiki edits
    1

    Default Re: QComboBox Problem

    my_widget.h:

    Qt Code: 
    1. #include <QtGui>
    2.  
    3. class MyWidget : public QWidget
    4. {
    5.     Q_OBJECT
    6.     public:
    7.         MyWidget(QWidget* parent = 0)
    8.         {
    9.             QHBoxLayout* layout = new QHBoxLayout(this);
    10.             combo1 = new QComboBox(this);
    11.             combo2 = new QComboBox(this);
    12.  
    13.             layout->addWidget(combo1);
    14.             layout->addWidget(combo2);
    15.  
    16.             combo1->addItem("combo_item1");
    17.             combo1->addItem("combo_item2");
    18.             combo2->addItem("combo_item3");
    19.             combo2->addItem("combo_item4");
    20.  
    21.             connect(combo1, SIGNAL(currentIndexChanged(const QString&)),
    22.             this,   SLOT(_onCombo1_currentIndexChanged(const QString&)));
    23.         }
    24.  
    25. private slots:
    26.         void _onCombo1_currentIndexChanged(const QString &arg1)
    27.         {
    28.             QString val("trololo");
    29.             //take value from database here...
    30.  
    31.             combo2->setItemText(0, val);
    32.         }
    33.  
    34.     private:
    35.         QComboBox* combo1;
    36.         QComboBox* combo2;
    37. };
    To copy to clipboard, switch view to plain text mode 

    main.cpp:

    Qt Code: 
    1. #include "my_widget.h"
    2.  
    3. int main(int argc, char** argv)
    4. {
    5.     QApplication app(argc, argv);
    6.  
    7.     MyWidget w;
    8.     w.show();
    9.  
    10.     return app.exec();
    11. }
    To copy to clipboard, switch view to plain text mode 

    This example works fine for me.
    It's will be much harder to find a problem if your actual problem is in your database code.
    But synchronization between two combo boxes is not a problem.

    If I've got you wrong, can you tell me:
    what is a value that query5.value(0).toString() returns?
    was ui variable constructed?
    was setupUi method called?
    Reply With Quote Reply With Quote

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

    anouar2002 (19th January 2012)
  6. 19th January 2012, 23:14 #5
    anouar2002
    anouar2002 is offline Novice
    Join Date
    Jan 2012
    Posts
    25
    Thanks
    10
    Qt products
    Qt4
    Platforms
    Windows

    Default Re: QComboBox Problem

    Hello, thank you for answering me again.

    I didn't understand your code perfectly. In fact, i can't see the utility of creating everything on header( i use the header only for declaration)
    I will answer your questions :
    query5.value(0).toString returns the num_Four from my base
    ui is the mainwindow widget
    and i will post the hole code here :

    fiche_article.cpp :
    Qt Code: 
    1. #include "fiche_article.h"
    2. #include "ui_fiche_article.h"
    3. #include <QtDebug>
    4.  
    5. fiche_article::fiche_article(QWidget *parent) :
    6.     QDialog(parent),
    7.     ui(new Ui::fiche_article)
    8. {
    9.     ui->setupUi(this);
    10.     this->model = new QSqlQueryModel();
    11.            model->setQuery("SELECT  Nom FROM Projet.dbo.Produit");
    12.            ui->comboBox->setModel(model);
    13.  
    14.  
    15.            QSqlQuery query;
    16.            query.prepare("SELECT  Matricule FROM Projet.dbo.Produit WHERE Nom=:nom");
    17.            query.bindValue(":nom", ui->comboBox->currentText());
    18.            if (query.exec() && query.next()) {
    19.                ui->lineEdit_3->setText(query.value(0).toString());
    20.            }
    21.          //  QObject::connect(ui->comboBox, SIGNAL(currentIndexChanged(int)),ui->lineEdit_3, SLOT(setText(ui->comboBox->currentText())));
    22.  
    23.            QSqlQuery query2;
    24.            query2.prepare("SELECT  Nom FROM Projet.dbo.Produit WHERE Nom=:nom");
    25.            query2.bindValue(":nom", ui->comboBox->currentText());
    26.            if (query2.exec() && query2.next()) {
    27.                ui->lineEdit->setText(query2.value(0).toString());
    28.            }
    29.  
    30.  
    31.            QSqlQuery query3;
    32.            query3.prepare("SELECT  Type FROM Projet.dbo.Produit WHERE Nom=:nom");
    33.            query3.bindValue(":nom", ui->comboBox->currentText());
    34.            if (query3.exec() && query3.next()) {
    35.                ui->lineEdit_2->setText(query3.value(0).toString());
    36.  
    37.            }
    38.  
    39.            QSqlQuery query4;
    40.            query4.prepare("SELECT  Quantité FROM Projet.dbo.Produit WHERE Nom=:nom");
    41.            query4.bindValue(":nom", ui->comboBox->currentText());
    42.            if (query4.exec() && query4.next()) {
    43.                ui->spinBox->setValue(query4.value(0).toInt());
    44.  
    45.  
    46.            }
    47.            this->model2 = new QSqlQueryModel();
    48.                   model2->setQuery("SELECT DISTINCT N_Four FROM Projet.dbo.Produit");
    49.                   ui->comboBox_2->setModel(model2);
    50.  
    51.  
    52.                   QSqlQuery query5;
    53.                   query5.prepare("SELECT  N_Four FROM Projet.dbo.Produit WHERE Nom=:nom");
    54.                   query5.bindValue(":nom", ui->comboBox->currentText());
    55.                   if (query5.exec() && query5.next()) {
    56.                       ui->comboBox_2->setItemText(0,query5.value(0).toString());
    57.  
    58.                   }
    59.  
    60.  
    61. }
    62.  
    63. fiche_article::~fiche_article()
    64. {
    65.     delete ui;
    66. }
    67.  
    68. void fiche_article::on_comboBox_currentIndexChanged(const QString &arg1)
    69. {
    70.  
    71.     QSqlQuery query;
    72.     query.prepare("SELECT  Matricule FROM Projet.dbo.Produit WHERE Nom=:nom");
    73.     query.bindValue(":nom", ui->comboBox->currentText());
    74.     if (query.exec() && query.next()) {
    75.         ui->lineEdit_3->setText(query.value(0).toString());
    76.     }
    77.     QSqlQuery query3;
    78.     query3.prepare("SELECT  Type FROM Projet.dbo.Produit WHERE Nom=:nom");
    79.     query3.bindValue(":nom", ui->comboBox->currentText());
    80.     if (query3.exec() && query3.next()) {
    81.         ui->lineEdit_2->setText(query3.value(0).toString());
    82.     }
    83.  
    84.     QSqlQuery query4;
    85.     query4.prepare("SELECT  Quantité FROM Projet.dbo.Produit WHERE Nom=:nom");
    86.     query4.bindValue(":nom", ui->comboBox->currentText());
    87.     if (query4.exec() && query4.next()) {
    88.         ui->spinBox->setValue(query4.value(0).toInt());
    89.  
    90.     }
    91.  
    92.  
    93. }
    To copy to clipboard, switch view to plain text mode 

    fiche_article.h :
    Qt Code: 
    1. #ifndef FICHE_ARTICLE_H
    2. #define FICHE_ARTICLE_H
    3.  
    4. #include <QDialog>
    5. #include <QtGui>
    6. #include <QtSql>
    7. #include <QtCore>
    8.  
    9. namespace Ui {
    10.     class fiche_article;
    11. }
    12.  
    13. class fiche_article : public QDialog
    14. {
    15.     Q_OBJECT
    16.  
    17. public:
    18.     explicit fiche_article(QWidget *parent = 0);
    19.     ~fiche_article();
    20.  
    21. private slots:
    22.     void on_comboBox_currentIndexChanged(const QString &arg1);
    23.  
    24. private:
    25.     Ui::fiche_article *ui;
    27.     QSqlQuery *qry;
    28.     QString *sQuery;
    29.  
    30.  
    31.  
    33.     QSqlQueryModel *model2;
    34.  
    35.  
    36. };
    37.  
    38. #endif // FICHE_ARTICLE_H
    To copy to clipboard, switch view to plain text mode 

    main.cpp :
    Qt Code: 
    1. #include <QtGui/QApplication>
    2. #include "mainwindow.h"
    3.  
    4. int main(int argc, char *argv[])
    5. {
    6.     QApplication a(argc, argv);
    7.     MainWindow w;
    8.     w.show();
    9.  
    10.     return a.exec();
    11. }
    To copy to clipboard, switch view to plain text mode 

    and there are many others pages
    Reply With Quote Reply With Quote
« Previous Thread | Next Thread »

Similar Threads

  1. Problem with QComboBox
    By wagmare in forum Newbie
    Replies: 4
    Last Post: 1st December 2011, 10:25
  2. QComboBox problem
    By SteveH in forum Newbie
    Replies: 2
    Last Post: 2nd March 2009, 21:20
  3. QComboBox problem
    By ^NyAw^ in forum Qt Programming
    Replies: 4
    Last Post: 31st March 2008, 11:43
  4. Problem while using QComboBox
    By merry in forum Qt Programming
    Replies: 6
    Last Post: 20th December 2007, 10:22
  5. Problem with QComboBox
    By jogeshwarakundi in forum Qt for Embedded and Mobile
    Replies: 1
    Last Post: 8th December 2007, 13:21

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Forum Rules

Digia, Qt and their respective logos are trademarks of Digia Plc in Finland and/or other countries worldwide.