qt在window实现调取摄像头识别二维码条形码不会保存图片到本机多个摄像头可切换无摄像头或格式不识别不崩溃会提示加线程处理

#include “MainWindow.h“
#include 

int main（int argc char *argv[]）
{
    QApplication a（argc argv）;
    MainWindow w;
    w.show（）;

    return a.exec（）;
}

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----

     文件        646  2019-01-06 19:13  SmartMemory.qmake.stash

     文件      90540  2019-04-10 10:26  SmartMemory1111.png

     文件   24742912  2019-03-13 19:50  SmartMemoryjilu.db

     文件        185  2019-04-11 16:45  SmartMemorymain.cpp

     文件        958  2019-04-19 11:36  SmartMemorymainwindow.cpp

     文件        541  2019-04-17 10:47  SmartMemorymainwindow.h

     文件       2026  2019-04-12 13:13  SmartMemorymainwindow.ui

     文件      20976  2019-04-19 12:46  SmartMemoryMakefile

     文件     272875  2019-04-19 12:46  SmartMemoryMakefile.Debug

     文件     273991  2019-04-19 12:46  SmartMemoryMakefile.Release

     文件       1436  2019-04-19 16:44  SmartMemorymythread.cpp

     文件        548  2019-04-19 09:00  SmartMemorymythread.h

     文件       7084  2019-04-19 16:43  SmartMemorymyvideosurface.cpp

     文件       1009  2019-04-19 09:00  SmartMemorymyvideosurface.h

     文件       3425  2019-04-19 12:46  SmartMemoryobject_script.SmartMemory.Debug

     文件       3679  2019-04-19 12:46  SmartMemoryobject_script.SmartMemory.Release

     文件      10462  2018-11-08 16:42  SmartMemoryPICMyURL.ico

     文件        964  2009-10-16 18:37  SmartMemoryPICstock_search.png

     文件      14504  2018-08-02 02:00  SmartMemoryQZXing.pri

     文件       6045  2019-04-19 16:32  SmartMemoryqzxingcamera.cpp

     文件        994  2019-04-18 00:10  SmartMemoryqzxingcamera.h

     文件       4570  2019-04-19 11:06  SmartMemoryqzxingcamera.ui

     文件      32359  2019-04-17 23:17  SmartMemory
eleaseAztecDecoder.o

     文件      50562  2019-04-17 23:17  SmartMemory
eleaseAztecDetector.o

     文件      10090  2019-04-17 23:16  SmartMemory
eleaseAztecDetectorResult.o

     文件      15436  2019-04-17 23:16  SmartMemory
eleaseAztecReader.o

     文件       1023  2019-04-17 23:16  SmartMemory
eleaseBarcodeFormat.o

     文件      12316  2019-04-17 23:17  SmartMemory
eleaseBigInteger.o

     文件       6935  2019-04-17 23:17  SmartMemory
eleaseBigIntegerAlgorithms.o

     文件       6721  2019-04-17 23:17  SmartMemory
eleaseBigIntegerUtils.o

............此处省略712个文件信息