一、QT(WIN10)安装

1.首先下载QT(VS有对应的QT)

下载链接
windows程序的后缀是.exe
Ubuntu程序的后缀是.run

2.安装QT

按照安装指示操作、注册QT，然后出现”选择“界面时勾选“MinGW 7.3.0 64-bit”，“MSVC 2017 64-bit”；点击“Developer and Designer Tools”前的尖号，打开其中选项，勾选“MinGW 7.3.0 64-bit”。

二、将QT加载到VS中

在VS"工具"→"扩展与更新"→"联机"中搜索“QT”并下载，重启生效

三、QT设置

1.在VS"Qt Vs Tools"→"QT Versions"中添加"msvc2017_64"qmake的路径

2.在"General"→"QT Designer"中将"False"改为"True"

四、QT程序打包

1.新建QT Widges项目，Base class也选择"QWidget"类(QMainWindow是一个含有菜单的窗口、QDialog是对话框、QWidget是不确定的窗口)

2.先在VS中使用Release模式发布，在x64中找到生成的exe

3.在空白处"shift"+右键打开Windows PowerShell模式，使用QT自带的搜索程序QT\mingw73_64\bin\windeployqt.exe将exe需要的动态库都拷贝过来

4. 安装包制作，首先下载Inno Setup官方链接

5.新建脚本模式

6.修改程序信息

7.设置打包程序位置

8.添加原始exe和文件夹路径

9.下面这个关联格式的不要点

10.创建快捷方式(无需修改)

11.设置安装向导(无需修改)

12.选择安全模式(无需修改)

13.语言选择(无需修改，没得中文)

14.设置安装文件的相关信息（生成的exe位置、名称、图标和安装时的密码）

后面的一路ok就好了就可以打开了

#五、第一个项目(摄像头播放)

要用到opencv调摄像头，所以把opencv也配置到vs中：
1.在”VC++目录"→“包含目录”中增加opencv\bulid的include和include中的opencv2路径
2.在"库目录"中增加opencv\build\x64\vc15\lib路径
3.在"链接器"→"输入"→"附加依赖项"中增加opencv_worldxxx_lib（如果配置为Debug，选择opencv_worldxxxd.lib
如果为Release，选择opencv_worldxxx.lib）

1.原代码(已改过命名方式)

ui

/********************************************************************************
** Form generated from reading UI file 'QT_learning1.ui'
**
** Created by: Qt User Interface Compiler version 5.14.2
**
** WARNING! All changes made in this file will be lost when recompiling UI file!
********************************************************************************/#ifndef UI_QT_LEARNING1_H
#define UI_QT_LEARNING1_H#include <QtCore/QVariant>
#include <QtWidgets/QApplication>
#include <QtWidgets/QLabel>
#include <QtWidgets/QPushButton>
#include <QtWidgets/QWidget>QT_BEGIN_NAMESPACEclass Ui_QT_learning1Class
{
public:QPushButton *Open_Camera;QPushButton *Capture;QPushButton *Close_Camera;QLabel *Video;QLabel *Photo;QLabel *label;QLabel *label_2;void setupUi(QWidget *QT_learning1Class){if (QT_learning1Class->objectName().isEmpty())QT_learning1Class->setObjectName(QString::fromUtf8("QT_learning1Class"));QT_learning1Class->resize(600, 400);Open_Camera = new QPushButton(QT_learning1Class);Open_Camera->setObjectName(QString::fromUtf8("Open_Camera"));Open_Camera->setGeometry(QRect(100, 330, 93, 28));Capture = new QPushButton(QT_learning1Class);Capture->setObjectName(QString::fromUtf8("Capture"));Capture->setGeometry(QRect(250, 330, 93, 28));Close_Camera = new QPushButton(QT_learning1Class);Close_Camera->setObjectName(QString::fromUtf8("Close_Camera"));Close_Camera->setGeometry(QRect(400, 330, 93, 28));Video = new QLabel(QT_learning1Class);Video->setObjectName(QString::fromUtf8("Video"));Video->setGeometry(QRect(40, 40, 224, 224));Photo = new QLabel(QT_learning1Class);Photo->setObjectName(QString::fromUtf8("Photo"));Photo->setGeometry(QRect(310, 40, 224, 224));label = new QLabel(QT_learning1Class);label->setObjectName(QString::fromUtf8("label"));label->setGeometry(QRect(110, 280, 81, 16));label_2 = new QLabel(QT_learning1Class);label_2->setObjectName(QString::fromUtf8("label_2"));label_2->setGeometry(QRect(410, 280, 72, 15));retranslateUi(QT_learning1Class);QMetaObject::connectSlotsByName(QT_learning1Class);} // setupUivoid retranslateUi(QWidget *QT_learning1Class){QT_learning1Class->setWindowTitle(QCoreApplication::translate("QT_learning1Class", "QT_learning1", nullptr));Open_Camera->setText(QCoreApplication::translate("QT_learning1Class", "\346\211\223\345\274\200\346\221\204\345\203\217\345\244\264", nullptr));Capture->setText(QCoreApplication::translate("QT_learning1Class", "\346\213\215\347\205\247", nullptr));Close_Camera->setText(QCoreApplication::translate("QT_learning1Class", "\345\205\263\351\227\255\346\221\204\345\203\217\345\244\264", nullptr));Video->setText(QString());Photo->setText(QString());label->setText(QCoreApplication::translate("QT_learning1Class", "\346\221\204\345\203\217\345\244\264\351\242\204\350\247\210", nullptr));label_2->setText(QCoreApplication::translate("QT_learning1Class", "\347\205\247\347\211\207", nullptr));} // retranslateUi};namespace Ui {class QT_learning1Class: public Ui_QT_learning1Class {};
} // namespace UiQT_END_NAMESPACE#endif // UI_QT_LEARNING1_H

h文件

#pragma once#include <QtWidgets/QWidget>
#include "ui_QT_learning1.h"#ifndef QT_LEARNING1_H
#define QT_LEARNING1_H#include <opencv2\core\core.hpp>
#include <QWidget>
#include <QImage>
#include <QTimer>     // 设置采集数据的间隔时间#include <QGraphicsScene>  
#include <QGraphicsView>  #include <highgui/highgui_c.h>  //包含opencv库头文件#include <opencv2\imgproc\imgproc.hpp>
#include <opencv2\core\core.hpp>
#include <opencv2\highgui\highgui.hpp>  //opencv申明#include <opencv.hpp>
using namespace cv;namespace Ui {class QT_learning1;
}class QT_learning1 : public QWidget
{Q_OBJECTpublic:explicit QT_learning1(QWidget *parent = 0);~QT_learning1();private slots:void openCamara();      // 打开摄像头void getFrame();       // 读取当前帧信息void closeCamara();     // 关闭摄像头。void takingPictures();  // 拍照private:Ui::QT_learning1Class ui;QTimer    *timer;QImage    *imag;CvCapture *cam;// 视频获取结构， 用来作为视频获取函数的一个参数IplImage  *frame;VideoCapture capture1;Mat showimage;QImage Mat2Qimage(Mat cvImg);//QT_learning1(QWidget * parent);//申请IplImage类型指针，就是申请内存空间来存放每一帧图像
};#endif // QT_LEARNING1_H

cpp文件
（摄像头找不到得话，将capture1.open(0)中的0改成1或者-1试试）

#include "QT_learning1.h"
#include<stdlib.h>
#include <ctime>
#include<random>
#include<opencv.hpp>
using namespace cv;
using namespace std;QT_learning1::QT_learning1(QWidget *parent) :QWidget(parent)
{ui.setupUi(this);connect(ui.Open_Camera, SIGNAL(clicked()), this, SLOT(openCamara()));connect(ui.Capture, SIGNAL(clicked()), this, SLOT(takingPictures()));connect(ui.Close_Camera, SIGNAL(clicked()), this, SLOT(closeCamara()));setWindowTitle(tr("Main Window"));timer = new QTimer(this);imag = new QImage();connect(timer, SIGNAL(timeout()), this, SLOT(getFrame()));//超时就读取当前摄像头信息
}
QT_learning1::~QT_learning1()
{}void QT_learning1::openCamara()
{capture1.open(0);                                            //打开摄像头，从摄像头中获取视频timer->start(10);}void QT_learning1::getFrame() {capture1 >> showimage;QImage imag = Mat2Qimage(showimage);ui.Video->setScaledContents(true);ui.Video->setPixmap(QPixmap::fromImage(imag));
}void QT_learning1::closeCamara()
{timer->stop();ui.Video->clear();capture1.release();
}void QT_learning1::takingPictures()
{capture1.open(0);capture1 >> showimage;QImage img = Mat2Qimage(showimage);ui.Photo->setScaledContents(true);ui.Photo->setPixmap(QPixmap::fromImage(img));string writePath = "./";string name;time_t now = time(0);name = writePath + to_string(now) + ".jpg";imwrite(name, showimage);}QImage QT_learning1::Mat2Qimage(Mat cvImg)
{// 8-bits unsigned, NO. OF CHANNELS = 1if (cvImg.type() == CV_8UC1){QImage image(cvImg.cols, cvImg.rows, QImage::Format_Indexed8);// Set the color table (used to translate colour indexes to qRgb values)image.setColorCount(256);for (int i = 0; i < 256; i++){image.setColor(i, qRgb(i, i, i));}// Copy input Matuchar *pSrc = cvImg.data;for (int row = 0; row < cvImg.rows; row++){uchar *pDest = image.scanLine(row);memcpy(pDest, pSrc, cvImg.cols);pSrc += cvImg.step;}return image;}// 8-bits unsigned, NO. OF CHANNELS = 3else if (cvImg.type() == CV_8UC3){// Copy input Matconst uchar *pSrc = (const uchar*)cvImg.data;// Create QImage with same dimensions as input MatQImage image(pSrc, cvImg.cols, cvImg.rows, cvImg.step, QImage::Format_RGB888);return image.rgbSwapped();}else if (cvImg.type() == CV_8UC4){//		qDebug() << "CV_8UC4";// Copy input Matconst uchar *pSrc = (const uchar*)cvImg.data;// Create QImage with same dimensions as input MatQImage image(pSrc, cvImg.cols, cvImg.rows, cvImg.step, QImage::Format_ARGB32);return image.copy();}else{//		qDebug() << "ERROR: Mat could not be converted to QImage.";return QImage();}
}

main.cpp

#include "QT_learning1.h"
#include <QtWidgets/QApplication>int main(int argc, char *argv[])
{QApplication a(argc, argv);QT_learning1 w;w.show();return a.exec();
}

效果
还行，但有两个问题：
1.拍照得到的照片失真，原因是打开摄像头和拍照重复使用摄像头接口，导致数据传输变慢、冲突
2.没有多线程，如果再来个功能或者运算量变大就over了

2.把cpp文件替换为下面得即可解决第一个问题

#include "QT_learning1.h"
#include<stdlib.h>
#include <thread>
#include <ctime>
#include<random>
#include<opencv.hpp>
using namespace cv;
using namespace std;QT_learning1::QT_learning1(QWidget *parent) :QWidget(parent)
{ui.setupUi(this);connect(ui.Open_Camera, SIGNAL(clicked()), this, SLOT(openCamara()));connect(ui.Capture, SIGNAL(clicked()), this, SLOT(takingPictures()));connect(ui.Close_Camera, SIGNAL(clicked()), this, SLOT(closeCamara()));setWindowTitle(tr("Main Window"));timer = new QTimer(this);imag = new QImage();connect(timer, SIGNAL(timeout()), this, SLOT(getFrame()));//超时就读取当前摄像头信息
}
QT_learning1::~QT_learning1()
{}void QT_learning1::openCamara()
{capture1.open(0);                                            //打开摄像头，从摄像头中获取视频timer->start(10);}void QT_learning1::getFrame() {capture1 >> showimage;QImage imag = Mat2Qimage(showimage);ui.Video->setScaledContents(true);ui.Video->setPixmap(QPixmap::fromImage(imag));
}void QT_learning1::closeCamara()
{timer->stop();ui.Video->clear();capture1.release();
}void QT_learning1::takingPictures()
{QImage img = Mat2Qimage(showimage);ui.Photo->setScaledContents(true);ui.Photo->setPixmap(QPixmap::fromImage(img));string writePath = "./";string name;time_t now = time(0);name = writePath + to_string(now) + ".jpg";imwrite(name, showimage);}QImage QT_learning1::Mat2Qimage(Mat cvImg)
{// 8-bits unsigned, NO. OF CHANNELS = 1if (cvImg.type() == CV_8UC1){QImage image(cvImg.cols, cvImg.rows, QImage::Format_Indexed8);// Set the color table (used to translate colour indexes to qRgb values)image.setColorCount(256);for (int i = 0; i < 256; i++){image.setColor(i, qRgb(i, i, i));}// Copy input Matuchar *pSrc = cvImg.data;for (int row = 0; row < cvImg.rows; row++){uchar *pDest = image.scanLine(row);memcpy(pDest, pSrc, cvImg.cols);pSrc += cvImg.step;}return image;}// 8-bits unsigned, NO. OF CHANNELS = 3else if (cvImg.type() == CV_8UC3){// Copy input Matconst uchar *pSrc = (const uchar*)cvImg.data;// Create QImage with same dimensions as input MatQImage image(pSrc, cvImg.cols, cvImg.rows, cvImg.step, QImage::Format_RGB888);return image.rgbSwapped();}else if (cvImg.type() == CV_8UC4){//		qDebug() << "CV_8UC4";// Copy input Matconst uchar *pSrc = (const uchar*)cvImg.data;// Create QImage with same dimensions as input MatQImage image(pSrc, cvImg.cols, cvImg.rows, cvImg.step, QImage::Format_ARGB32);return image.copy();}else{//		qDebug() << "ERROR: Mat could not be converted to QImage.";return QImage();}
}

这样就ok了

3.多线程

C++中可直接使用thread库实现
而QT提供了两种方式实现多线程：
1.继承QThread的run函数，是个虚函数，会自动调用的
2.继承于QObject的类用moveToThread函数转移到一个Thread里
第一种QThread已经不推荐了，我们使用QObject实现

1.QObject实现思路

1.创键一个继承于 QObject 的自定义线程类（如：MyThread），用来盛放比较耗时，需要放入子线程的处理函数
（1）定义一个线程处理函数(如：MyWork），当然也可以定义多个，这时多个处理函数就共用一个子线程
（2）在处理函数中进行处理，此过程可能时间较长（如：QThread::sleep(1)）
（3）在处理函数中发送处理完成的信号（如：emit signal_back()），当然该信号中可能含有处理的结果信息（如计算结果）

2、 在主线程（亦称界面线程）中创建一个子线程（QThread* subthread = new QThread(this)）

3、新建一个自定义线程类对象（MyThread* m_MyThread = new MyThread()）

4、将自定义线程类对象移入子线程容器中（m_MyThread->moveToThread(subthread)），其实也可以移入多个自定义线程类到同一个subthread中，这时他们就共享一个子线程了

5、连接主线程和子线程之间的信号和槽
（1）主线程——>子线程，主线程的信号和子线程的槽
connect ( this, &MainWindow::StartThread, m_MyThread, &MyThread::MyWork )
（2）子线程——>主线程，子线程的信号和主线程的槽
connect (m_MyThread, &MyThread::signal_back, this, &MainWindow::slot_handle_finish )

6、子线程使用完毕需要回收销毁，不然该线程会一直占用，而系统可分配的线程数量是有限的

（1）subthread->qiut(); //该停止函数比较弱，会等到线程处理函数MyWork()的任务执行完之后，才会停止线程

（2）subthread->wait();

所有通常会加入一个标志位，来终止任务。
未完待续。。。