无法连接(空)::selectionChanged 到 QTableView

Cannot connect (null)::selectionChanged to QTableView

我有以下提升的QTableView:

class QRightClickableTableView : public QTableView {
  Q_OBJECT
public:
  explicit QRightClickableTableView(QWidget *parent = 0): QTableView(parent) {}

private slots:
  void mouseReleaseEvent(QMouseEvent *e) {
    if(e->button()==Qt::RightButton)
      emit rightClicked();
    else if (e->button()==Qt::LeftButton)
      emit leftClicked();
  }

signals:
  void rightClicked();
  void leftClicked();
};

绑定QRightClickableTableView的selectionChanged信号时,报错。在 .cpp 中:

QRightClickableTableView *table = ui->dataTableView;
connect(table, SIGNAL(leftClicked()), this, SLOT(on_tableViewLeftClicked()));
connect(table, SIGNAL(rightClicked()), this, SLOT(on_tableViewRightClicked()));

connect(table->selectionModel(), SIGNAL(selectionChanged(QItemSelection, QItemSelection)),
    SLOT(on_tableViewSelectionChanged(QItemSelection)));
table->setModel(model);

leftClicked 和 rightClicked 信号按预期工作,但出现错误:

QObject::connect: Cannot connect (null)::selectionChanged(QItemSelection, QItemSelection) to MyApp::on_tableViewSelectionChanged(QItemSelection)

信号槽连接失败,因为 table->selectionModel() return 为空。

如果您在进行信号槽连接之前为您的 table 设置模型,table->selectionModel() 将 return 成为有效模型,使信号槽连接成功。