c++ - 在 C++/Qt 中作为 lambda 函数参数的槽

Question

我有一个 lambda 方法，我想接收一个槽作为参数

我最终得到:

  auto createShortcuts = [ = ]( const QString &sequence, const std::function < void () > &slot  )
  {
    QShortcut *sc = new QShortcut( QKeySequence( sequence ), this );
    connect( sc, &QShortcut::activated, mMyObject, slot );
  };

  createShortcuts( QStringLiteral( "whatever" ), [=](){mMyObject->mySlot();} );

但我希望在调用 createShortcuts 时避免使用 lambda 槽。而是类似

  auto createShortcuts = [ = ]( const QString &sequence, void ( MyObject::* )() )
  {
    QShortcut *sc = new QShortcut( QKeySequence( sequence ), this );
    connect( sc, &QShortcut::activated, mMyObject, ??? );
  };

  createShortcuts( QStringLiteral( "whatever" ), &MyObject::mySlot );

但我找不到调用该插槽的正确语法。

Answer 1

这应该可行，你只是缺少函数指针的名称。

  auto createShortcuts = [ = ]( const QString &sequence, void ( MyObject::* myFunc )() )
  {
    QShortcut *sc = new QShortcut( QKeySequence( sequence ), this );
    connect( sc, &QShortcut::activated, mMyObject, myFunc);
  };

  createShortcuts( QStringLiteral( "whatever" ), &MyObject::mySlot );

编辑: 上述解决方案仅在 mMyObject 在同一作用域中声明 createShortcuts 时才有效，下面的方案更安全。

  auto createShortcuts = [ = ]( const QString &sequence, const MyObject* mMyObject, void ( MyObject::* myFunc )() )
  {
    QShortcut *sc = new QShortcut( QKeySequence( sequence ), this );
    connect( sc, &QShortcut::activated, mMyObject, myFunc);
  };
  auto obj = new MyObject();
  createShortcuts( QStringLiteral( "whatever" ), obj, &MyObject::mySlot );