Problem to reset QVector

LodiCode

Hello guys,

I made a struct like this:

struct VeiculoImages{
   int id;
   QByteArray img;
   QDate dateUpload;
};

I am using a QVector to store it, but i have a problem to delete all, when i use my QVector again its send me error "index out of range"

i am try use many ways to remove all elements but didn't work.


    images.erase(images.begin(), images.end());
//
images.clear();
// 
for(int i = images.size(); i>=0; i--){
    images.takeAt(i);
}

thanks alot for you time! sorry for bad english...

Hi! Just use clear(). After that, the vector has a size of zero.

LodiCode

@Wieland don't work, i still getting out of range when i try to add new itens!

@LodiCode Please show some code.

LodiCode

@Wieland

this is the error
ASSERT failure in QVector<T>::operator[]: "index out of range", file C:/Qt/Qt5.7.0/5.7/mingw53_32/include/QtCore/qvector.h, line 433

my function is

void Historico::getImages()
{
    query = Connection::getQueryInstance();


    ui->edit_imagens->clear();
    images.clear();

    query.prepare("SELECT * FROM veiculos_fotos WHERE veiculo_id=:veiculo_id");
    query.bindValue(":veiculo_id", veiculo_id);
    VeiculoImages veic;
    if(query.exec())
        while(query.next()){
            veic.id = query.value(0).toInt();
            veic.img = query.value(1).toByteArray();
            veic.dateUpload = query.value(3).toDate();
            images.push_back(veic);
        }

    for(int i =0; i<images.size(); i++){
        ui->edit_imagens->addItem("ID Foto = "+QString::number(images[i].id)+" | Data Upload ="+ images[i].dateUpload.toString("dd-MM-yyyy"));
    }
    Connection::getInstance(false);
}

my header is

#ifndef HISTORICO_H
#define HISTORICO_H

#include <QDialog>
#include "connection.h"

struct VeiculoImages;
namespace Ui {
class Historico;
}

class Historico : public QDialog
{
    Q_OBJECT

public:
    explicit Historico(QWidget *parent = 0);
    ~Historico();

private:
    Ui::Historico *ui;
    //private functions;
    void setupHistorico();
    void controlConnections();

    //vars
    QSqlQuery query;
    int veiculo_id; // get by placaToID()
    QString proprietarioByID(int);

    //moneys
    double gastosTotal = 0;
    double ganhosTotal = 0;
    double lucroTotal  = 0;
    QVector<VeiculoImages> images;

protected slots:
    void generateHistory();
    void placaToID();
    void loadInformations();

    //tables load
    void loadGastos();
    void loadGanhos();
    void loadNegociacao();

    //image load
    void getImages();
    void loadImages(int);
};

struct VeiculoImages{
   int id;
   QByteArray img;
   QDate dateUpload;
};
#endif // HISTORICO_H

I don't see any reason why the code shouldn't work. Does the debugger really say that the line with "clear" triggers the exception?

LodiCode

@Wieland thanks for you help bro, my problem is solved, the error is logical, the vector and function clear is ok,

the problem is my connect(), i used a signal CurrentIndexChanged(), now i am change to activated(), when clear() is called it call another function that use the vector to get information about the images, and this function access out of range vector index!

Andy314

I have not read the whole thread, but in the first code is a simple index error yet.

for(int i = images.size(); i>=0; i--){
    images.takeAt(i);

Last index is size()-1 !

LodiCode

@Andy314 you is right my fault!

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Solved Problem to reset QVector