I have the most basic of Qt programs - a main window. I want to be able to use QPainter to draw some lines - nothing more than lines really (I'm trying to plot a histogram). Anyway I've read code examples but for some reason my code isn't working.
I have a mainwindow.ui which creates a class called MainWindow which I haven't shown - it's just a QMainWindow with a QWidget on it but I'm hiding the QWidget as I haven't used it now. main.cc is not shown too because it's the standard main.cc for a small project. The rest of the code is:
mainwindow.cc
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QWidget>
#include <QPainter>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent)
{
setupUi(this);
drawingArea->hide();
QPainter painter(this);
painter.begin(this);
QColor color (100, 100, 100);
painter.setBrush(color);
painter.drawLine(0,0,10,10);
}
MainWindow::~MainWindow()
{
}
mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include "ui_mainwindow.h"
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow, private Ui::MainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
private:
};
#endif // MAINWINDOW_H
you need to do painting in paintEvent.