Qt android paintevent problem？
-
#include "mainwindow.h"
#include "ui_mainwindow.h"MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
}MainWindow::~MainWindow()
{
delete ui;
}void MainWindow::paintEvent(QPaintEvent *event)
{
QPainter painter(this);
painter.setPen(QPen(Qt::red,4));
painter.drawLine(QPoint(10,10),QPoint(100,400)); //drawLine() Without any effect, without any display？
painter.setBrush(Qt::yellow);
painter.drawRect(100,100,100,100);//drawRect() Without any effect, without any display？
}//On the QT Android 6 system。
//drawLine()，drawRect() Without any effect, without any display？
//How to use painter()?? -
Usually, you are not supposed to draw on QMainWindow directly. You should only draw on elements placed on the window.
Also, when you claim that a function call does not have any effect, check first that it gets executed - It may well be that your paintEvent doesn't get called, lacking a reason to update it... (there should be an update() call generated somewhere).
-
#include "mainwindow.h"
#include "ui_mainwindow.h"MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
}MainWindow::~MainWindow()
{
delete ui;
}void MainWindow::paintEvent(QPaintEvent *event)
{
QPainter painter(this);
painter.setPen(QPen(Qt::red,4));
painter.drawLine(QPoint(10,10),QPoint(100,400)); //drawLine() Without any effect, without any display？
painter.setBrush(Qt::yellow);
painter.drawRect(100,100,100,100);//drawRect() Without any effect, without any display？
}//On the QT Android 6 system。
//drawLine()，drawRect() Without any effect, without any display？
//How to use painter()??
