雜記

Qt 5.0 以後connection更新, 可以將slot設定為 function, 而非一定要是QObject, 且slot 可以有更加靈活的用法 (並非一定要有相對應parameter之slot function, 其他成員函式亦可執行): 

New: connecting to QObject member

Here's Qt 5's new way to connect two QObjects and pass non-string objects:

connect(
    sender, &Sender::valueChanged,
    receiver, &Receiver::updateValue
);

Pros

• Compile time check of the existence of the signals and slot, of the types, or if the Q_OBJECT is missing.
• Argument can be by typedefs or with different namespace specifier, and it works.
• Possibility to automatically cast the types if there is implicit conversion (e.g. from QString to QVariant)
• It is possible to connect to any member function of QObject, not only slots.

Cons

• More complicated syntax? (you need to specify the type of your object)
• Very complicated syntax in cases of overloads? (see below)
• Default arguments in slot is not supported anymore.

New: connecting to simple function

The new syntax can even connect to functions, not just QObjects:

connect(
    sender, &Sender::valueChanged,
    someFunction
);

Pros

• Can be used with std::bind:

connect(
    sender, &Sender::valueChanged,
    std::bind( &Receiver::updateValue, receiver, "senderValue", std::placeholders::_1 )
);

• Can be used with C++11 lambda expressions:

connect(
    sender, &Sender::valueChanged,
    [=]( const QString &newValue ) { receiver->updateValue( "senderValue", newValue ); }
);

Cons

• There is no automatic disconnection when the 'receiver' is destroyed because it's a functor with no QObject. However, since 5.2 there is an overload which adds a "context object". When that object is destroyed, the connection is broken (the context is also used for the thread affinity: the lambda will be called in the thread of the event loop of the object used as context).

官網網址如下:

http://doc.qt.io/qt-5/signalsandslots.html

https://wiki.qt.io/New_Signal_Slot_Syntax

自建Model:

可用於QML中的ListView, 如此就不會限制於只能用簡單QStringList對應的ModelData

可自訂data role (兩種以上data role的model)

範例如下

http://doc-snapshots.qt.io/qt5-5.11/qtquick-models-objectlistmodel-example.html