Qt应用程序启动但不显示

Question

I have a strange problem, I had developed 2 months ago a small project and I started to work on it again.

The problem is that the application starts (as I can click on the stop button in the IDE to kill it). But the windows does not show. No error messages are shown, I tried to launch it outside of the IDE (with all DLLs and platform plugins). But this is the same.

Here is my MainWindow constructor :

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow) {
    qDebug() << "R";
    ui->setupUi(this);
    ui->statusbar->setSizeGripEnabled(false);
    recorder = new QAudioRecorder(this);
    createTempDir();
    this->canProcessData = false;

    this->state = WAITING;
    this->mode = NONE;

    connect(this->recorder, SIGNAL(durationChanged(qint64)),
            this, SLOT(updateDuration(qint64)));
    connect(this->recorder, SIGNAL(statusChanged(QMediaRecorder::Status)),
            this, SLOT(updateStatus(QMediaRecorder::Status)));
    connect(this->recorder, SIGNAL(stateChanged(QMediaRecorder::State)),
            this, SLOT(onStateChanged(QMediaRecorder::State)));
    connect(this->recorder, SIGNAL(error(QMediaRecorder::Error)),
            this, SLOT(showError()));

    // list settings
    foreach(const QString &device, recorder->audioInputs()) {
        ui->input_device->addItem(device, QVariant(device));
    }
    foreach(const QString &codec, recorder->supportedAudioCodecs()) {
        ui->codec->addItem(codec, QVariant(codec));
    }
    foreach(int sample_rate, recorder->supportedAudioSampleRates()) {
        ui->sample_rate->addItem(QString::number(sample_rate), QVariant(sample_rate));
    }

    this->log("Ready :)");
}

Here is main.cpp code:

#include "mainwindow.h" 
#include <QApplication> 

int main(int argc, char *argv[]) {
    QApplication a(argc, argv); 

    qDebug() << "A"; 

    MainWindow w; 
    w.setFixedSize(720,455); 
    w.setWindowFlags(w.windowFlags() |= Qt::MSWindowsFixedSizeDialogHint); 
    w.show(); 

    return a.exec(); 

}

As i you can see, I have a qDebug() << "R"; at the first line but it does not even show.

I googled it but obviously all that I could find was topics where it was a DLL problem.

I think its worth mentionning that when I dropped the project 2 months ago I was on the same PC and all the paths (compiler, libraries and Qt) are the same.

I you know something I would be grateful to you.

Answer 1

也许您使用的库定义了另一个main入口点，但是您的那个不会被调用。