QLineEdit text not retrieved

[trojansmith1990]

i cannot access or retrieve text from my QLineEdit object......i have given the object name as "dist"
and declared as:

QLineEdit *dist=new QLineEdit(this);

and tried to retrieve text with:

dist->text();

and later i am converting text to int by:

bool ok=1;
QString str=dist->text().toInt(&ok,10);

the value of ok before converting is 1 and after converting(toInt) is 0.....
i dunno why it is not converting or why it is not retrieving values from object name "dist"....
using Qt4....ubuntu

i also have QMetaObject(connectslotsbyname) in my ui_mainwindow.h file....could anyone kindly please help

[Zlatomir]

If the ok variable is false it means that the conversion didn't succeed, see the documentation here.

And this line:

dist->text();

dist->text();

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doesn't store the returned QString, use it like:

QString stringFromLineEdit = dist->text();

QString stringFromLineEdit = dist->text();

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And make sure your code is executed after the lineEdit dist have the input you expect.

[Santosh Reddy]

may be you should use int instead of QString

int number = dist->text().toInt(&ok,10);

int number = dist->text().toInt(&ok,10);

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[trojansmith1990]

void MainWindow::on_plot_clicked()
{
    bool ok=true;
    cout<<"ok:"<<ok<<endl;
    dist=new QLineEdit(this);
    azim=new QLineEdit(this);
 
    QString r=(dist->text());
    QString a=(azim->text());
    QByteArray barray=r.toLatin1();
    const char *ch=barray.constData();
    int rad = atoi(ch);
 
    QByteArray barray2=a.toLatin1();
    const char *ch2=barray2.constData();
    int ang = atoi(ch2);
 
 
    float x=rad*cos(ang);
    float y=rad*sin(ang);
 
    cout<<"ch:"<<ch<<endl;
    cout<<"a:"<<ang<<endl;
    cout<<"ok:"<<ok<<endl;
    QGraphicsItem *obj1=scene->addRect(x,y,x+10,y+10);
 
}

void MainWindow::on_plot_clicked()
{
    bool ok=true;
    cout<<"ok:"<<ok<<endl;
    dist=new QLineEdit(this);
    azim=new QLineEdit(this);

    QString r=(dist->text());
    QString a=(azim->text());
    QByteArray barray=r.toLatin1();
    const char *ch=barray.constData();
    int rad = atoi(ch);

    QByteArray barray2=a.toLatin1();
    const char *ch2=barray2.constData();
    int ang = atoi(ch2);


    float x=rad*cos(ang);
    float y=rad*sin(ang);

    cout<<"ch:"<<ch<<endl;
    cout<<"a:"<<ang<<endl;
    cout<<"ok:"<<ok<<endl;
    QGraphicsItem *obj1=scene->addRect(x,y,x+10,y+10);

}

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this was my mainwindow.cpp

here is my header file:

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QMainWindow>
#include <QLineEdit>
#include <QMessageBox>
#include <QGraphicsScene>
#include <QGraphicsView>
#include <QPainter>
#include <QRectF>
#include <QGraphicsEllipseItem>
#include <QString>
#include <QGraphicsScale>
#include <QMetaObject>
 
namespace Ui {
    class MainWindow;
}
 
class MainWindow : public QMainWindow
{
    Q_OBJECT
 
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
    QGraphicsView *view;
    QGraphicsScene *scene;
    QPainter *paint;
    static const int min_x=0;
    static const int min_y=0;
    static const int max_x=500;
    static const int max_y=500;
    QGraphicsEllipseItem *ell1;
    QGraphicsEllipseItem *ell2;
    QGraphicsEllipseItem *center;
    QLineEdit *dist;
    QLineEdit *azim;
    QLineEdit *scale;
    QString sc_str;
    QGraphicsScale *sc;
 
 
private:
    Ui::MainWindow *ui;
 
private slots:
 
 
private slots:
    void on_scale_map_clicked();
 
    void on_plot_clicked();
};
 
#endif // MAINWINDOW_H

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QLineEdit>
#include <QMessageBox>
#include <QGraphicsScene>
#include <QGraphicsView>
#include <QPainter>
#include <QRectF>
#include <QGraphicsEllipseItem>
#include <QString>
#include <QGraphicsScale>
#include <QMetaObject>

namespace Ui {
    class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
    QGraphicsView *view;
    QGraphicsScene *scene;
    QPainter *paint;
    static const int min_x=0;
    static const int min_y=0;
    static const int max_x=500;
    static const int max_y=500;
    QGraphicsEllipseItem *ell1;
    QGraphicsEllipseItem *ell2;
    QGraphicsEllipseItem *center;
    QLineEdit *dist;
    QLineEdit *azim;
    QLineEdit *scale;
    QString sc_str;
    QGraphicsScale *sc;


private:
    Ui::MainWindow *ui;

private slots:


private slots:
    void on_scale_map_clicked();

    void on_plot_clicked();
};

#endif // MAINWINDOW_H

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this is not working.....

[Zlatomir]

Are you sure that you show the QLineEdit declared by you in your class QLineEdit *dist; and not some other QLineEdit generated from the ui file?

[trojansmith1990]

ya sorry...i used int to store it itself ...just messed up....this somethiing new i tried....but failed too.....

int number = dist->text().toInt(&ok,10);

was not working.....it looks trivial....but anyway thanks for trying....

---

Added after 6 minutes:

its still not working...i tried with the latest code given above.....the two samples pasted above.....not working.....

please look in "dist" variable and "azim"....line 8 of mainwindow.cpp onwards...thank you

yes....i have declared QLineEdit.....not generated....

yes i did declare it myself...

its still not working...i tried with the latest code given above.....the two samples pasted above.....not working.....

please look in "dist" variable and "azim"....line 8 of mainwindow.cpp onwards...thank you

[wysota]

Could you add this line right before the one with toInt() and tell us what it prints (you'll need to #include <QtDebug> as well)?

qDebug() << "Line edit text:" << dist->text();

qDebug() << "Line edit text:" << dist->text();

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[Zlatomir]

I know that you declare it yourself, but what i wanted to say is to check if you don't somehow show some other QLineEdit from the ui (from designer) and that have the text you expected - because from the code you posted i see you have a designer file and you also code some more QWidgets.

[Santosh Reddy]

..
dist=new QLineEdit(this);
azim=new QLineEdit(this);
 
QString r=(dist->text());
QString a=(azim->text());
...

..
dist=new QLineEdit(this);
azim=new QLineEdit(this);

QString r=(dist->text());
QString a=(azim->text());
...

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You are creating the QLineEdit and immediatly reading the input, when will the user/operator get a chance to enter data / number ?

May you need to create QLineEdit's earlier somewhere like ctor, then read them in the plot_slot....