How to get the file's extend name in C++ - 在C++中如何获取文件的扩展名

1、

CString CPrjGetFileExtendNameDlg::GetFileExtendNameBetter(CString strFileName)
{
	int intCharPosition;

	//Find "//",Get The File's Name
	intCharPosition = strFileName.ReverseFind('//');
	if(-1 != intCharPosition)
	{
		strFileName = strFileName.Right(strFileName.GetLength() - intCharPosition - 1);
	}

	//Find ".",Get the file's extend name
	intCharPosition = strFileName.ReverseFind('.');
	if(-1 != intCharPosition)
	{
		strFileName = strFileName.Right(strFileName.GetLength() - intCharPosition - 1);
		return strFileName;
	}
	else
	{
		//No extend name
		return "";
	}
	
}

2、

CString CPrjGetFileExtendNameDlg::GetFileExtendName(CString strFileName)
{
	int intCharPosition;
	//Find "//",Get The File's Name
	while(1)
	{
		intCharPosition = strFileName.Find("//");
		if(-1 != intCharPosition)
		{
			strFileName = strFileName.Right(strFileName.GetLength() - intCharPosition - 1);
		}
		else
		{
			break;
		}

	}

	//Find ".",Get the file's extend name
	//No extend name
	if(-1 == strFileName.Find("."))
	{
		return "";
	}
	else
	{
		while(1)
		{
			intCharPosition = strFileName.Find(".");
			if(-1 != intCharPosition)
			{
				strFileName = strFileName.Right(strFileName.GetLength() - intCharPosition - 1);
			}
			else
			{
				break;
			}

		}
		return strFileName;
	}
}