opencv 学习第一天 学习opencv（中文版）创建一个类似滚动条

#include <opencv2/highgui/highgui.hpp>
#include <cv.h>
#include <iostream>
using namespace cv;
using namespace std;
int g_slider_position = 0;
CvCapture *g_cap = nullptr;
void onTrackbarslide(int pos)
{
	cvSetCaptureProperty(g_cap,CV_CAP_PROP_POS_FRAMES,pos);
}
void main()
{
	cvNamedWindow("example3",CV_WINDOW_AUTOSIZE);
	g_cap = cvCreateFileCapture("D:\1.wmv");
	int frames = static_cast<int>(cvGetCaptureProperty(g_cap,CV_CAP_PROP_FRAME_COUNT));
	if (frames != 0)
	{
		cvCreateTrackbar("position","example3",&g_slider_position,frames,onTrackbarslide);
	}
	IplImage *frame;
	while(1)
	{
		frame = cvQueryFrame(g_cap);
		if(!frame)
			break;
		cvShowImage("example3",frame);
		char c = waitKey(33);
		if (c == 27)
		{
			break;
		}
	}
	cvReleaseCapture(&g_cap);
	cvDestroyWindow("example3");
	system("pause");
}#include <opencv2/highgui/highgui.hpp>
#include