QProcess不发出已完成的信号

Question

我试着读出在QProcess中执行的命令的输出。我无法在QProcess的已完成信号和已完成的处理程序之间建立连接。我尝试了几种连接到QProcess完成信号的不同方式，但到目前为止还没有成功。我知道进程的执行是因为它在GUI的控制台中打印输出，而流程的完成是因为它从顺序API中传递了waitForFinished方法。

为什么我的代码不按onFinish或onFinishNoPams

标题：

class Test : public QObject
{
    Q_OBJECT
public:
    Test(QObject *parent = 0);

    Q_INVOKABLE void read();
public slots:
    void onFinish(int exitCode , QProcess::ExitStatus exitStatus);
    void onFinishNoPams();

private:
    QProcess *m_process;

};

cpp：

Test::Test(QObject *parent)
    : QObject(parent)
{}
void Test::read(){
    m_process=new QProcess(this);

    connect(m_process, SIGNAL(finished(int,QProcess::ExitStatus)), this, SLOT(onFinishNoPams()));

    connect(m_process, SIGNAL(finished(int,QProcess::ExitStatus)), this, SLOT(onFinish(int,QProcess::ExitStatus)));

    connect(m_process, QOverload<int, QProcess::ExitStatus>::of(&QProcess::finished),
        [=](int exitCode, QProcess::ExitStatus exitStatus){
    qDebug() << "not reached";
    });

    connect(m_process, QOverload<int, QProcess::ExitStatus>::of(&QProcess::finished), this,&Test::onFinish);

    QString program = "lsusb";
    QStringList arguments;
    m_process->execute(program,arguments);
    m_process->waitForFinished();
    qDebug() << "reached";
    return;
}

void Test::onFinish(int exitCode , QProcess::ExitStatus exitStatus){
    qDebug() << "not reached";
}

void Test::onFinishNoPams(){
    qDebug() << "not reached";
    QByteArray out=m_process->readAllStandardOutput();
}

qml：

import test 1.0

Window {    
    Test{
        id:test
        Component.onCompleted: test.read()
    }
}

Answer 1

QProcess::execute()是一个静态方法，它启动外部进程并以阻塞方式等待其完成。这与您的m_process变量无关。您想要使用的是QProcess::start()。