QT单例类管理信号和槽函数

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前言

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在QT当中，遇到主界面和多个组件槽函数绑定问题时，为了便于管理，我们可以通过单例类作为第三方来进行管理。

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一、创建单例类

SignalInstance.h

#include 

class  SignalInstance:public QObject
{
	Q_OBJECT
public:
	static SignalInstance	*GetInstance();
	static void Release();//释放
	static SignalInstance *signalinstance;
 signals:
	 void send_to_windwostwo();
	 void send_to_windwosone();
private:
	SignalInstance();
};

SignalInstance.cpp

```cpp
#include "SignalInstance.h"
SignalInstance* SignalInstance::signalinstance = nullptr;//初始化对象
//释放单例对象
void SignalInstance::Release()
{
	if (signalinstance != NULL)
	{
		delete signalinstance;
		signalinstance = NULL;
	}
}
SignalInstance::SignalInstance()
{
	
}
//获得单例对象
SignalInstance* SignalInstance::GetInstance()
{
	if (signalinstance == NULL)
	{
		signalinstance = new SignalInstance();
	}
	return signalinstance;
}

二、主界面添加组件

代码如下（示例）：

#include 
#include
#include 
#include "SignalInstance.h"
#include"QtWidgets_1.h"
#include"QtWidgetsClass_2.h"
#include "instanse.h"
instanse::instanse(QMainWindow *parent)
    : QMainWindow(parent)
{
    ui.setupUi(this);
	QVBoxLayout *lay = new QVBoxLayout(this);
	QtWidgets_1 *widget1 = new QtWidgets_1();
	lay->addWidget(widget1);
	ui.widget->setLayout(lay);
	QVBoxLayout *lay2 = new QVBoxLayout(this);
	QtWidgetsClass_2 *widget2 = new QtWidgetsClass_2();
	lay2->addWidget(widget2);
	ui.widget_2->setLayout(lay2);
}

三、组件代码绑定信号和槽

1.组件1

#pragma once

#include 
#include "ui_QtWidgets_1.h"

class QtWidgets_1 : public QWidget
{
	Q_OBJECT

public:
	QtWidgets_1(QWidget *parent = Q_NULLPTR);
	~QtWidgets_1();
private slots:
	void Show();
private:
	Ui::QtWidgets_1 ui;
};

#include "QtWidgets_1.h"
#include"SignalInstance.h"
#include 
#include 
#pragma execution_character_set("utf-8")
QtWidgets_1::QtWidgets_1(QWidget *parent)
	: QWidget(parent)
{
	ui.setupUi(this);
	connect(ui.pushButton, SIGNAL(clicked()), SignalInstance::GetInstance(), SIGNAL(send_to_windwostwo()));//绑定信号
	connect(SignalInstance::GetInstance(), SIGNAL(send_to_windwosone()), this, SLOT(Show()));//绑定槽函数
}

QtWidgets_1::~QtWidgets_1()
{

}
void QtWidgets_1::Show()
{
	ui.textEdit->setText("我是窗口2激活的");
}

2.组件2

#pragma once

#include 
#include "ui_QtWidgetsClass_2.h"

class QtWidgetsClass_2 : public QWidget
{
	Q_OBJECT

public:
	QtWidgetsClass_2(QWidget *parent = Q_NULLPTR);
	~QtWidgetsClass_2();
private slots:
	void Show();
private:
	Ui::QtWidgetsClass_2 ui;
};


#include "QtWidgetsClass_2.h"
#include"SignalInstance.h"
#include 
#include 
#pragma execution_character_set("utf-8")
QtWidgetsClass_2::QtWidgetsClass_2(QWidget *parent)
	: QWidget(parent)
{
	ui.setupUi(this);
	connect(SignalInstance::GetInstance(), SIGNAL(send_to_windwostwo()),this,SLOT(Show()));//绑定槽函数
	connect(ui.pushButton, SIGNAL(clicked()), SignalInstance::GetInstance(), SIGNAL(send_to_windwosone()));//绑定信号
}

QtWidgetsClass_2::~QtWidgetsClass_2()
{
}
void QtWidgetsClass_2::Show()
{
	ui.textEdit->setText("我是窗口1激活的");
}

四、效果图

下载地址：https://download.csdn.net/download/qq_38491692/85309274

总结

本文案例使用组件较少，当项目较大时，比如上千个控件和布局，能有效的对信号和槽进行管理。如果对您有帮助，请点个赞。