Qt将itemChanged信号附加到QStandardItem不起作用

Question

I'm using qtreeview trying to find out when ever the check box state changes, but the SLOT method never fires.

Here is my code:

 // in the init 
 connect(ui.treeView_mainwindow, SIGNAL(itemChanged( const QModelIndex &)), this,
             SLOT(tree_itemChanged( const QModelIndex &)));  

 // this method never trigered
 void GroupMainWindowContainer::tree_itemChanged(const QModelIndex & index)
{


     QStandardItem* standardItem  = m_model->itemFromIndex(index);
     Qt::CheckState checkState = standardItem->checkState();
     if(checkState == Qt::Checked)
     {
        WRITELOG("Qt::Checked")

     }
     else if(checkState == Qt::Unchecked)
     {
        WRITELOG("Qt::Unchecked")
     }

}


// this is how i build the items :
  QList<QStandardItem *> items;
  items.insert(0,new QStandardItem());
  items.at(0)->setCheckable(true);
  items.at(0)->setCheckState(Qt::Unchecked);


  m_model->insertRow(0,items);

Answer 1

QTreeView doesn't have an itemChanged signal, so your QObject::connect call will fail.

This is a good example of why you should always check the return value from QObject::connect . Also, the failed connection would have appeared in your debug output, which you should also be monitoring.

Possibly you're looking for QTreeWidget , which inherits from QTreeView and does have an itemChanged signal, albeit one that has an QTreeWidgetItem* as a parameter, not a const QModelIndex& .