CString提取数字

int GetNumber(CString str)
{
    //这是测试的字符串   提取1010这个数字
    //CString str = _T("Y2hlbmppbmdjb25n1010.ts");

	int nRight = str.Find(_T(".ts")), flag = 1, nLeft;

    //显示找到的字符在的位置、字符串长度
	//CString nTow1, nTow2;
	//nTow1.Format(_T("%d"), nRight);
	//nTow2.Format(_T("%d"), str.GetLength());
	//AfxMessageBox(nTow1 + _T("：") + nTow2);

	nLeft = nRight;
	CString GetNum;
	while (flag)
	{
		nLeft = nLeft - 1;
        //将CString的一个字符转换成TCHAR，容易进行取值范围
		TCHAR bj1 = str.GetAt(nLeft), bj2 = _T('0'), bj3 = _T('9');
		if (bj1 >= bj2 && bj1 <= bj3)
		{
			GetNum = GetNum + str.GetAt(nLeft);    //数字集合在一起
		}
		else
		{
			GetNum.MakeReverse();   //将字符串顺序颠倒
			flag = 0;
		}
	}
	//AfxMessageBox(GetNum);
	int num = _wtoi(GetNum);
    return num;
}