判断闰年---简单0.0

/// <summary>
/// 判断是否闰年？
/// </summary>
/// <param name="a_year"></param>
/// <returns></returns>
public static bool IsLeapYear(int a_year)
{
String s;
DateTime dt;
try
{
s = (a_year.ToString() + "-02-29");
dt = Convert.ToDateTime(s);
return true;
}
catch
{
return false;
}
}