[QT] encapsulation of custom controls

Yes QT Custom control encapsulation .

1  Create a project , choice UI Interface , Inherit Widget class .

2  Create designer interface class , Right click on the item

Take the class name yourself , When it's done . Finally, it will generate ,h/.cpp/.ui file

3  Click the generated UI file

Drag the required controls . Use here Horizontal Slider and Spin Box.

The final effect is to drag Horizontal Slider,Spin Box The number of will change ; modify Spin Box The number of ,Horizontal Slider It will slide .

You can also modify initialization , The two should correspond

 4  stay ui Add in the interface widget Control , Promote it to the designer interface class created before

5  Create designer interface class （ Name self access ）

6  Use signal slots to complete requirements ;

6.1  The first set 【spinBox The numbers change , yes slider Slide with 】

see QSpinBox, It has an overloaded version , Use function pointers to complete , 

// spinBox The numbers change , yes slider Slide with 
//  A function pointer 
void(QSpinBox::* spin)(int) = &QSpinBox::valueChanged;
connect(ui->spinBox, spin, ui->horizontalSlider,&QSlider::setValue);

  next , Empathy

// slider Move ,spinBox The numbers change 
connect(ui->horizontalSlider, &QSlider::valueChanged, ui->spinBox, &QSpinBox::setValue);

 6.2  stay widget.ui Add two buttons ,【 Set to half 】 and 【 Set to half 】

stay Smallwidget Add two functions to the class 【 Set up the data 】 and 【 get data 】

Realization

  stay Widget.cpp To realize the signal and slot of the button

//  Click Set half 
connect(ui->btn_set, &QPushButton::clicked, this, [=](){
    ui->widget->setVal(50);
});

//  Click to get the current value 
connect(ui->btn_get, &QPushButton::clicked, this, [=](){
    qDebug() << ui->widget->getVal();
});

  effect