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View Full Version : Image is not show that load from sqlite database



binary001
21st January 2018, 18:37
Hi!

Photo are stored in a SQLite Database (from other application). Now I load data from database and want to load image in my label.
When I debug it, QByteArray is ok. But QPixmap is invalid. How can I fix it?

Thanks


.h file


#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QSqlDatabase>
#include <QSqlQuery>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
Q_OBJECT

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

QSqlDatabase myDb;
QSqlQuery *query;

private slots:
void on_pushButton_clicked();

private:
Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H


.cpp file


#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>
#include <QPixmap>
#include <QSqlError>
#include <QBuffer>

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
}

MainWindow::~MainWindow()
{
delete ui;
}

void MainWindow::on_pushButton_clicked()
{
myDb = QSqlDatabase::addDatabase("QSQLITE","myconnection");
myDb.setDatabaseName("D:/ArtistPhoto.db3");

if (!myDb.open()) {
qDebug() << " not open";
}
else {
qDebug() << " opened";
query = new QSqlQuery ("SELECT Data FROM Artist WHERE NOT data IS NULL",myDb);
if(query->first()) {
QByteArray outByteArray = query->value("Data").toByteArray();
QPixmap outPixmap = QPixmap();
outPixmap.loadFromData( outByteArray );
if(outPixmap.loadFromData(outByteArray,"PNG")) ui->label->setPixmap(outPixmap);

}
myDb.close();


}

}





Project source code and database file
http://bit.ly/2F1FNmd

high_flyer
22nd January 2018, 17:19
When I debug it, QByteArray is ok. But QPixmap is invalid.
What do you mean by 'ok'?
What does your QByteArray return for isNull() or isEmpty()?

binary001
22nd January 2018, 17:48
ok means

qDebug() << outByteArray.isEmpty() << outByteArray.isNull();

false false

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