问题描述
我正在使用 .NET DateTime 来获取当前日期和时间.我将其转换为字符串以用作文件名的一部分.问题是保存图像的 OpenCV 命令需要 char * 而不是字符串类型,而 DateTime 只会输出 String^ 类型.我该如何进行这项工作?这里的代码没有完成
I am using the .NET DateTime to get the current date and time. I am converting it to a string to use as part of a file name. The problem is the OpenCV command to save an image requires a char * not a string type, and DateTime will only output a String^ type. How do I make this work? Heres the code not completed
String^ nowString = DateTime::Now.ToString("yyyy-MM-dd-HH:mm");
IplImage* toSave;
CvCapture* capture = cvCreateCameraCapture(0);
toSave = cvQueryFrame( capture );
cvSaveImage(nowString, toSave);
cvReleaseImage(&toSave);
cvReleaseCapture(&capture);
推荐答案
最好的办法是使用 StringToHGlobalAnsi
.这是完整的代码,展示了它是如何完成并记住释放分配的内存的.
Your best bet is to use StringToHGlobalAnsi
. Here is complete code showing how its done and remembering to free the memory allocated.
using namespace System::Runtime::InteropServices;
void MethodName()
{
String^ nowString = DateTime::Now.ToString("yyyy-MM-dd-HH:mm");
IntPtr ptrToNativeString = Marshal::StringToHGlobalAnsi(nowString);
try
{
CvCapture* capture = cvCreateCameraCapture(0);
IplImage* toSave = cvQueryFrame(capture);
cvSaveImage(static_cast<char*>(ptrToNativeString.ToPointer()), toSave);
cvReleaseImage(&toSave);
cvReleaseCapture(&capture);
}
catch (...)
{
Marshal::FreeHGlobal(ptrToNativeString);
throw;
}
Marshal::FreeHGlobal(ptrToNativeString);
}
您可能需要重新考虑在文件名中使用:"字符,因为我不相信 windows 非常喜欢这个.
You might want to rethink using a ':' character in the filename, as I don't believe windows likes this very much.
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