QT控件使用范例

设置窗口属性

为防止通过setWindowTitle 设置的窗口标题出现中文乱码的问题，需要将设置的参数进行一个转换，可以通过fromLocal8Bit 函数转换后就不会出现中文乱码的问题了。

learn::learn(QWidget *parent)
    : QMainWindow(parent)
    , bnt(nullptr)
{
    ui.setupUi(this);

    QString iconpath = "../Resource Files/WIN_20221114_17_56_03_Pro.jpg";
    //设置窗口标题
    setWindowTitle(QString::fromLocal8Bit("QT5.1窗口"));
    //设置窗口固定大小
    setMinimumSize(300, 300);
    setMaximumSize(300, 300);
    //设置窗口的背景颜色为红色
    this->setStyleSheet("background:red");
    //修改窗口的图标
    this->setWindowIcon(QIcon(iconpath));
}

字体形状窗体

将窗体背景色透明，根据图片形状显示窗体

void learn::SetLucency()
{
	//去掉标题栏
    this->setWindowFlags(Qt::FramelessWindowHint);
    //设置透明
    this->setAttribute(Qt::WA_TranslucentBackground, true);
    /*
		qss语句解释：
		background-image ：背景图片
		url(xxx)   填写文件路径
		background-repeat:no-repeat;  不平铺
	*/
    this->setStyleSheet("background-image:url(C:/Users/26961/Desktop/1.png); background-repeat:no-repeat;");
}

QPushButton 按钮

在窗体中创建按钮 A，点击按钮 A，改变文字为按钮 B。

#pragma once

#include <QtWidgets/QMainWindow>
#include "ui_learn.h"
#include <QPushButton>
#include <qtimer.h>
#include <qpoint.h>
#include <QDebug>
#include <QMouseEvent>  

class learn : public QMainWindow
{
    Q_OBJECT

public:

    learn(QWidget *parent = nullptr);
    ~learn();
    // 按钮移动
    void MovePushButton();
    //鼠标点击
    void PressMouseEvent(QMouseEvent* e);
    //鼠标松开
    void ReleaseMouseEvent(QMouseEvent* e);
    //鼠标移动
    void MoveMouseEvent(QMouseEvent* e);
    //设置透明
    void SetLucency();
    //修改按钮
    void ChangeButtonText();
private:
    Ui::learnClass ui;
    QPushButton* bnt;
    QPoint last; //记录鼠标最近一次的坐标点
};


void learn::ChangeButtonText()
{
    if (!bnt)
    {
        delete bnt;
        bnt = nullptr;
    }
    bnt = new QPushButton(QString::fromLocal8Bit("修改文本"), this);
    //设置按钮的原点和宽高
    bnt->setGeometry(QRect(100, 100, 100, 25));
    //注册按钮处理事件
    connect(bnt, &QPushButton::clicked, this, [=]() 
        {
            bnt->setText(QString::fromLocal8Bit("按钮已经修改"));
        });
}

QLabel

在窗体中创建 QLabel 标签显示“我是 QLabel”字样，红色加粗倾斜字体。

void learn::ChangeLabel()
{
	if (!label)
    {
        delete label;
        label = nullptr;
    }
	//指定父对象， 设置Qlable文本
    this->label = new QLabel(QString::fromLocal8Bit("我是QLabel"), this);
    this->setGeometry(QRect(100, 100, 100, 25));
    /*
        font-size:20px  字体大小
        color:red       设置颜色
        font-weight:bold 字宽
        font-style:italic 字体样式
    */
    //设置Qlable qss样式
    label->setStyleSheet("font-size:20px; font-weight:bold; font-style:italic");
}

QLineEdit 单行文本

对输入的密码会进行一个隐藏设置

void learn::ChangeLineEdit()
{
    if (!line)
    {
        delete line;
        line = nullptr;
    }
    this->line = new QLineEdit(this);
    //设置单行坐标和宽高
    line->setGeometry(QRect(100, 100, 300, 25));
    //设置单行文本样式
    line->setStyleSheet("font-size:20px; font-weight:bold; font-style:italic");
    //限制最大长度为12
    line->setMaxLength(12);

	//不可写设置
    //line->setEchoMode(QLineEdit::NoEcho);

    //对密码进行隐藏设置
    line->setEchoMode(QLineEdit::Password);
}

QComboBox 下拉列表框

void learn::AddCharActer()
{
    if (this->box) {
        delete box;
        box = nullptr;
    }
    box = new QComboBox(this);
    box->setGeometry(QRect(100, 100, 300, 25));
    QStringList str;
    str << QString::fromLocal8Bit("数学")
        << QString::fromLocal8Bit("语文")
        << QString::fromLocal8Bit("地理");
    
    box->addItems(str);
}

QFontComboBox 字体下拉列表框

void learn::AddFontComboBox() 
{
	//创建字体下拉列表
    fontbox = new QFontComboBox(this);
    fontbox->setGeometry(QRect(100, 125, 300, 25));
    
    bnt = new QPushButton(QString::fromLocal8Bit("选择"), this);
    bnt->setGeometry(QRect(100, 100, 300, 25));
    
    line = new QLineEdit(this);
    line->setGeometry(QRect(100, 150, 300, 25));
    connect(bnt, &QPushButton::clicked, this, [=]()
        {
        	//当选择按钮被点击时，自动更换line 的信息
            line->setText(fontbox->currentText());
        });
}

QSpinBox 控件

void learn::AddSpinBox() 
{
    spin = new QSpinBox(this);
    spin->setGeometry(QRect(100, 125, 300, 25));

    //设置取值范围
    spin->setRange(0,100);
    //设置初始值
    spin->setValue(0);

	//除了初始值这些可以被修改，除此之外所有的文本都不允许被修改
    //后缀
    spin->setSuffix(QString::fromLocal8Bit("元/斤"));
    //前缀
    spin->setPrefix(QString::fromLocal8Bit("苹果"));
}

QTimeEdit 时间控件

void learn::AddTimeEdit() 
{
    time = new QTimeEdit(this);
    time->setGeometry(QRect(100, 125, 300, 25));
    
    //获取系统时间
    QDateTime systime = QDateTime::currentDateTime();
    
    //获取时分秒以“：”号拆分赋予 list 数组
    QStringList list = systime.toString("h:m:s").split(":");
    //打印系统时间
    qDebug() << list;
    //将时分秒绑定控件
    time->setTime(QTime(list[0].toInt(), list[1].toInt()));
}

QDateEdit 日期控件

void learn::AddDateEdit()
{
    date = new QDateEdit(this);
    date->setGeometry(QRect(100, 150, 300, 25));
    //获取系统时间
    QDateTime time = QDateTime::currentDateTime();
    QStringList list = time.toString("yyyy-MM-dd").split("-");
    date->setDate(QDate(list[0].toInt(), list[1].toInt(), list[2].toInt()));
}

QScrollBar 滑动条控件

void learn::AddScrollBar() 
{
    this->setWindowFlags(Qt::FramelessWindowHint);
    this->ScrollBar = new QScrollBar(this);
    this->spin = new QSpinBox(this);
    //横显/竖显
    ScrollBar->setOrientation(Qt::Horizontal);
    //指定大小
    ScrollBar->setGeometry(QRect(50, 50, 180, 20));
    spin->setGeometry(QRect(50, 90, 100, 25));
    
    //控制条宽度
    ScrollBar->setPageStep(10);
    
    //随着scrollBar 按钮在不断的移动的过程中，spin控件会及时更新 scrollBar 的现值
    connect(ScrollBar, &QScrollBar::valueChanged, spin, [=]()
        {
            spin->setValue(ScrollBar->value());
        });
}

QRadioButton 单选按钮

void learn::AddRadioButton() 
{
    label = new QLabel(this);
    label->setText(QString::fromLocal8Bit("选择内容："));
    line = new QLineEdit(this);

    this->radioW = new QRadioButton(QString::fromLocal8Bit("女人") , this);
    this->radioM = new QRadioButton(QString::fromLocal8Bit("男人"), this);
    //设置默认选择radioW
    radioW->setChecked(true);

    //位置
    line->setGeometry(QRect(130, 100, 100, 25));
    radioM->setGeometry(QRect(50, 50, 50, 50));
    radioW->setGeometry(QRect(100, 50, 50, 50));
    label->setGeometry(QRect(50, 100, 100, 25));

    connect(radioW, &QPushButton::clicked, this, [=]()
        {
            //当radioW 被勾选之后，label设置为radioW
            if (sender() == radioW) {
                this->line->setText(radioW->text());
            }
        });

    connect(radioM, &QPushButton::clicked, this, [=]()
        {
            //当radioW 被勾选之后，label设置为radioW
            if (sender() == radioM) {
                this->line->setText(radioM->text());
            }
        });
}

QCheckBox 复选框

void learn::AddCheckBox() 
{
    checkbox1 = new QCheckBox(QString::fromLocal8Bit("语文"), this);
    checkbox2 = new QCheckBox(QString::fromLocal8Bit("数学"), this);
    checkbox3 = new QCheckBox(QString::fromLocal8Bit("英语"), this);
    
    checkbox1->setGeometry(QRect(50, 50, 50, 50));
    checkbox2->setGeometry(QRect(100, 50, 50, 50));
    checkbox3->setGeometry(QRect(150, 50, 50, 50));
    label = new QLabel(this);
    label->setText(QString::fromLocal8Bit("选择内容："));
    line = new QLineEdit(this);
    label->setGeometry(QRect(50, 100, 100, 25));
    line->setGeometry(QRect(130, 100, 100, 25));
    bnt = new QPushButton(QString::fromLocal8Bit("提交信息"), this);
    
    auto process = [&]() 
    {
        auto interval = QString::fromLocal8Bit("、");
        if (sender() == checkbox1) {
            line->insert(checkbox1->text() + interval);
        }
        if (sender() == checkbox2) {
            line->insert(checkbox2->text() + interval);
        }
        if (sender() == checkbox3) {
            line->insert(checkbox3->text() + interval);
        }
    };
    connect(checkbox1, &QCheckBox::clicked, this, process);
    connect(checkbox2, &QCheckBox::clicked, this, process);
    connect(checkbox3, &QCheckBox::clicked, this, process);
}