我想问一下，为什么我这个代码不能实现在Qt项目点击pushbutton按钮改变label的文字

Question

.h文件

#ifndef REG_H
#define REG_H
#include <qgroupbox.h>
#include <QtWidgets/QWidget>
#include <QLabel>


class reg : public QWidget
{
    Q_OBJECT

public:
    reg(QWidget *parent = 0);
    ~reg();

private:
    QGroupBox *GroupBox_1();
    QGroupBox *GroupBox_2();
    QLabel *label_1;
    QLabel *label_2;

    public slots:
    void reg::change_text1();
    void reg::change_text2();
};

#endif // REG_H

.cpp

#pragma execution_character_set("UTF-8")
#include "reg.h"
#include "QPushButton.h"
#include <QLabel>
#include <QGroupBox>
#include <QGridLayout>
#include <QLayout>
#include <QVBoxLayout>
#include <QWidget>
#include <QString>
#include <QPlainTextEdit>
reg::reg(QWidget *parent)
: QWidget(parent)
{
    QGridLayout *gridLayout = new QGridLayout(this);
    gridLayout->setSpacing(100);
    gridLayout->setMargin(150);

    QVBoxLayout *vLayout_1 = new QVBoxLayout;
    QGroupBox *GroupBox_1 = new QGroupBox(QStringLiteral("GroupBox1"));
    QPushButton *button_1 = new QPushButton("按钮1");
    vLayout_1->addWidget(button_1);
    label_1 = new QLabel("label10");
    connect(label_1, SIGNAL(clicked(bool)), this, SLOT(change_text1()));
    vLayout_1->addWidget(label_1);
    GroupBox_1->setLayout(vLayout_1);
    gridLayout->addWidget(GroupBox_1, 0, 0, 50, 50);

    QVBoxLayout *vLayout_2 = new QVBoxLayout;
    QGroupBox *GroupBox_2 = new QGroupBox(QStringLiteral("GroupBox2"));
    QPushButton *button_2 = new QPushButton("按钮2");
    vLayout_2->addWidget(button_2);
    label_2 = new QLabel("label20");
    connect(label_2, SIGNAL(clicked(bool)), this, SLOT(change_text2()));
    vLayout_2->addWidget(label_2);
    GroupBox_2->setLayout(vLayout_2);
    gridLayout->addWidget(GroupBox_2, 0, 50, 50, 50);
}
reg::~reg()
{
}
void reg::change_text1()
{
    label_1->setText(QStringLiteral("la"));
}
void reg::change_text2()
{
    label_2->setText(QStringLiteral("lab"));
}

求解决，自己百度几个小时都没有解决；

Answer 1

1）成员函数
void reg::change_text1();
void reg::change_text2();
这两个写法错误。
void change_text1();
void change_text2();

2）connect(label_1, SIGNAL(clicked(bool)), this, SLOT(change_text1()));这是给label的信号绑定槽

这里应该是 connect(button_1,SIGNAL(clicked()), this, SLOT(change_text1()));这样是给button的信号绑定槽

3）
label_1->setText("la");