Question

我试图切换QAction的图标。它取决于特定表的上下文。实际上，每当我启动message.cpp时它都在工作，但是当我在message.cpp上时它不会改变。如果我点击m_action4，我希望updateIcon()会更改我的图标，但它不会。我可以重新拍摄QAction吗？

首先，我在标题上设置变量：

message.h：

private:
QAction *m_action4;

以下是我的源代码： 的 message.cpp：

    QSqlQuery query0;
    m_action4 = new QAction(QIcon(":/images/silent1.png"), tr("Mute"), this);
    m_muteActive = false;
    query0.prepare("SELECT state FROM mute_state WHERE p_id=?");
    query0.addBindValue(m_pid);
    query0.exec();
    if (query0.next() && query0.value(0) == "1" )
    {
        {
            m_muteActive = true;
            m_action4->setIcon(QIcon(":/images/speaker.png"));
        }
    }
    m_actionBar->addButton(m_action4);
    connect(m_action4, SIGNAL(triggered()), this, SLOT(muteMessages()));

muteMessages()
{    
      QSqlQuery query; 
      query.prepare("UPDATE mute_state SET state=? , duration= ? , type=? WHERE p_id=?");
      if (m_muteActive)
      {
          query.addBindValue("0");
          query.addBindValue("0");
          m_muteActive = false;
      }
      else
      {
          query.addBindValue("1");
          query.addBindValue("525949");
          m_muteActive = true;
      }
      query.addBindValue("private");
      query.addBindValue(m_id);
      if (query.exec())
          qDebug()<<"query was executed";
    }
  QTimer::singleShot(100 , this, SLOT(updateIcon()));
}
updateIcon()
{
    if (m_muteActive)
        m_action4->setIcon(QIcon(":/images/silent1.png"));    
    else    
        m_action4->setIcon(QIcon(":/images/speaker.png"));    
}

Answer 1

您发布的代码运行正常。在删除不需要演示它的SQL查询之后，它就在这里：

#include <QApplication>
#include <QAction>
#include <QToolBar>
#include <QGridLayout>
#include <QPainter>

class Ui : public QWidget {
   QGridLayout m_grid;
   QToolBar m_actionBar;
   QIcon m_silent, m_speaker;
   QAction m_action4;
   bool m_muteActive;
   QPixmap drawText(const char * text, int size = 64) {
      QPixmap pix(size, size);
      QPainter p(&pix);
      p.setFont(QFont("helvetica", size*0.8));
      p.fillRect(pix.rect(), Qt::white);
      p.drawText(pix.rect(), QString::fromUtf8(text));
      return pix;
   }
public:
   Ui() :
      m_grid(this),
      m_silent(drawText("")),
      m_speaker(drawText("")),
      m_action4(tr("Mute"), this),
      m_muteActive(false)
   {
      m_grid.addWidget(&m_actionBar, 0, 0);
      m_actionBar.addAction(&m_action4);
      connect(&m_action4, &QAction::triggered, this, &Ui::muteMessages);
      updateIcon();
   }
   Q_SLOT void muteMessages() {
      m_muteActive = !m_muteActive;
      updateIcon();
   }
   Q_SLOT void updateIcon() {
      m_action4.setIcon(m_muteActive ? m_silent : m_speaker);
   }
};

int main(int argc, char *argv[])
{
   QApplication a(argc, argv);
   Ui ui;
   ui.show();
   return a.exec();
}

无法更改QAction的图标

1 个答案: