如何通过单击QPushbutton更新QTreeWidget

Question

I'm developing a Qt app in C++

I have create a layout with button bar, TreeView...

The Treeview is defined in my MainWindow.cpp

MainWindow::MainWindow()
{
    setWindowTitle(QString::fromUtf8("PULS"));
    resize(800,600);
    setUnifiedTitleAndToolBarOnMac(true);
    createDeviceStatusBar();
    createSectionBar();
    createTreeView();

    QWidget *MainWindowWidget = new QWidget();

    QVBoxLayout *MainWindowLayout = new QVBoxLayout(MainWindowWidget);

    BrowserSection = new QGroupBox();

    QWidget *BrowserWidget = new QWidget();
    QHBoxLayout *BrowserLayout = new QHBoxLayout(BrowserWidget);
    BrowserLayout->addWidget(SectionBar);
    BrowserLayout->addWidget(TreeSection);

    BrowserSection->setLayout(BrowserLayout);

    MainWindowLayout->addWidget(DeviceSection);
    MainWindowLayout->addWidget(BrowserSection);

    setCentralWidget(MainWindowWidget);
    show();
}

The createSectionBar() is a layout defined as below:

void MainWindow::createSectionBar()
{
    SectionBar = new QGroupBox();

    QVBoxLayout *SectionBarlayout = new QVBoxLayout;
    SectionBarlayout->setContentsMargins(QMargins(0,0,0,0));

    MusicButton = new QPushButton();
    MusicButton->setFixedSize(110,150);
    MusicButton->setIcon(QIcon(":/images/music.png"));
    MusicButton->setIconSize(QSize(90,144));
    MusicButton->setFlat(true);
    MusicButton->setAutoFillBackground(true);
    connect(MusicButton, SIGNAL(clicked()), this, SLOT(MusicTreeFile()));


    SectionBarlayout->addWidget(MusicButton);


    SectionBar->setLayout(SectionBarlayout);
}

The createTreeView() is defined as below to enable TreeView and Items.

void MainWindow::createTreeView()
{

    TreeSection = new QGroupBox();

    QVBoxLayout *TreeLayout = new QVBoxLayout;

    MyTree = new TreeWidget();

    MyTree->setSortingEnabled(true);
    MyTree->setColumnWidth(0, 400);

    QTreeWidgetItem* headerItem = new QTreeWidgetItem();
    headerItem->setText(0,QString("File Name"));
    headerItem->setText(1,QString("Size (Bytes)"));
    headerItem->setText(2,QString("Date"));
    MyTree->setHeaderItem(headerItem);
    MyTree->setAutoFillBackground(true);

    TreeLayout->addWidget(MyTree);

    TreeSection->setLayout(TreeLayout);
}

What I need is to find a way to file the MyTree with

while (file != NULL && file->parent_id == folder_parent) {
    QTreeWidgetItem* item = new QTreeWidgetItem();  
    int i;  
    LIBMTP_file_t *oldfile;                 
    item->setText(0,file->filename);    
    Tree->addTopLevelItem(item);
    ....
}

here is the header file:

class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow();

protected:

private slots:
    void MusicTreeFile();

private:
    void createSectionBar();
    void createTreeView();
    void createDeviceStatusBar();

    QGroupBox *SectionBar;
    QGroupBox *TreeSection;
    QGroupBox *DeviceSection;
    QGroupBox *BrowserSection;

    QPushButton *MusicButton;

    TreeWidget *MyTree;

};

but it needs to be done only when clicking on MusicPushButton, I have already connected the MusicTreeFile() to the PushButton() action. but how to access to MyTree as it's also defined in another class..

Answer 1

You do not connect a signal to a class. You connect it to an instance of a class. And both of your instances are defined in MainWindow . So after both widgets are created you can call

QObject::connect(this->MusicButton, SIGNAL(clicked()), this->MyTree, SLOT(slot_name()));

With slot_name being your function

TreeWidget::slot_name{
    while (file != NULL && file->parent_id == folder_parent) {
        ....
    }
}