QFrame class study notes

1. The role of QFrame

       The QFrame class inherits from the QWidget class and is inherited by QAbstractScrollArea, QLabel, QLCDNumber, QSplitter, QStackedWidget, and QToolBox. As the base class of many basic controls, QFrame provides many member methods to subclasses to implement the design of the frame style of the subclass. Frame styles primarily consist of the frame shape and a shadow style used to visually separate the frame from surrounding widgets. Right now

1. QFrame provides member functions for designing frame styles for subclasses to help subclasses design unique styles: either raised borders, sunken borders, raised content, or sunken content, etc.
2. QFrame can also be used directly to create simple placeholder frames that contain no content.

2. QFrame member type document

     2.1 enum QFrame::Shadow   

         This enumeration type defines the type of shadow used to provide a 3D effect to frames.

QFrame::Plain	0x0010	Borders or content appear to be as tall as surrounding controls
QFrame::Raised	0x0020	Borders or content appear to be raised compared to surrounding controls
QFrame::Sunken	0x0030	Borders or content appear sunken compared to surrounding controls

     2.2 enum QFrame::Shape

                This enum type defines the shape of available frames.

QFrame::NoFrame	0	Don't draw anything
QFrame::Box	0x0001	Draw a border to wrap the content and highlight the shadow effect of the border
QFrame::Panel	0x0002	Draw a content plane to highlight the shadow effect of the content
QFrame::StyledPanel	0x0006	Draws a rectangular panel whose appearance depends on the current GUI style. It can be raised or sunken.
QFrame::HLine	0x0004	Draw a horizontal line to separate and highlight the shadow effect of the line
QFrame::VLine	0x0005	Draw a vertical line to separate and highlight the shadow effect of the line
QFrame::WinPanel	0x0003	Draws a rectangular panel that can be moved up or down like in Windows 2000. Specifying this shape sets the line width to 2 pixels. WinPanel is provided for compatibility.

 For GUI style independence, we recommend using StyledPanel instead.

   2.3 enum QFrame::StyleMask

          This enumeration defines two constants that can be used to extract the two components of frameStyle().

QFrame::Shadow_Mask	0x00f0	The shadow part of the control's framStyle() return value
QFrame::Shape_Mask	0x000f	The shape part of the control's framStyle() return value

   2.4 Style combinations that can be achieved using QFrame

3. Commonly used member functions of QFrame

     3.1 Introduction to member function prototypes

 

member function prototype	describe
QFrame(QWidget *parent = nullptr, Qt::WindowFlags f = Qt::WindowFlags())	Constructor
virtual   ~QFrame()	destructor
QRect frameRect() const	Get the frame size of QFrame
void setFrameRect(const QRect &)	Set the frame size of QFrame
QFrame::Shadow  frameShadow() const	Get the shadow style,
void setFrameShadow(QFrame::Shadow)	Set shadow style,
QFrame::Shape  frameShape() const	Get the shape of the frame
void setFrameShape(QFrame::Shape)	Set the shape of the frame
int  frameStyle() const	Get the frame's shape and shadow style
void setFrameStyle(int style)	Set the frame's shape and shadow style
int lineWidth() const	Get the width of the frame line
void setLineWidth(int)	Set the width of the frame lines
int midLineWidth() const	Get the width of the center line of the frame
void setMidLineWidth(int)	Set the width of the center line of the frame

   3.2 Simple example

       Use QLabel, a subclass of QFrame, to complete the design of a simple login interface. By changing the QLabel frame style, it is more consistent with the style of QLineEdit, QPushButton and other controls.

 

//.h文件
 
class Widget : public QWidget
{
    Q_OBJECT
 
public:
    Widget(QWidget *parent = nullptr);
    ~Widget();
private:
 
    QLabel *useLabel;
    QLabel *pwLabel;
    QLabel *useEdit;
    QLabel *pwEdit;
    QLabel *checkBtn;
    QLabel *cancelBtn;
 
};
 
//.c文件
 
Widget::Widget(QWidget *parent)
    : QWidget(parent)
{
    this->resize(400,550);
    useLabel = new QLabel(this);
    useLabel->setText("用户名:");
    useLabel->move(70,150);
    useLabel->resize(50,30);
    //设置"用户名"标签的框架样式为 无边框+无阴影
    useLabel->setFrameShape(QFrame::NoFrame);
    useLabel->setFrameShadow(QFrame::Plain);
 
    useEdit = new QLabel(this);
    useEdit->move(150,150);
    useEdit->resize(200,30);
    //设置"用户名"输入框的框架样式为 边框+突起
    useEdit->setFrameStyle(QFrame::Box|QFrame::Raised);
    useEdit->setLineWidth(2);
 
 
    pwLabel = new QLabel(this);
    pwLabel->setText("密码:");
    pwLabel->move(70,210);
    pwLabel->resize(50,30);
    //设置"密码"标签的框架样式为 无边框+无阴影
    pwLabel->setFrameStyle(QFrame::NoFrame|QFrame::Plain);
 
    pwEdit = new QLabel(this);
    pwEdit->move(150,210);
    pwEdit->resize(200,30);
    //设置"用户名"输入框的框架样式为 内容+凹陷
    pwEdit->setFrameStyle(QFrame::Panel|QFrame::Sunken);
    pwEdit->setLineWidth(2);
 
    checkBtn = new QLabel(this);
    checkBtn->setText("确认");
    checkBtn->setAlignment(Qt::AlignCenter);
    checkBtn->move(100,290);
    checkBtn->resize(80,30);
    //设置"确认"按钮的框架样式为 内容+突起
    checkBtn->setFrameStyle(QFrame::Panel|QFrame::Raised);
    checkBtn->setLineWidth(3);
 
 
    cancelBtn = new QLabel(this);
    cancelBtn->setText("取消");
    cancelBtn->setAlignment(Qt::AlignCenter);
    cancelBtn->move(240,290);
    cancelBtn->resize(80,30);
    //设置"取消"按钮的框架样式为 内容+突起
    cancelBtn->setFrameStyle(QFrame::Panel|QFrame::Raised);
    cancelBtn->setLineWidth(3);
 
}
 
 
 

Rendering: