public static Major GetMajorBLLInstance()
{
//如实例不存在，则New一个新实例，否则返回已有实例
if (MajorBLLInstance == null)
{
lock (syncRootMajor)
{
if (MajorBLLInstance == null)
MajorBLLInstance = new Major();
}
}
return MajorBLLInstance;
}
public static string GetMajorName(int id)
{
var bll = new Major();
return bll.GetModel(id).Name;
}