手动处理装箱Box

public static object GetSafeDbValue(object val)
{
if (val != null)
{
return val;
}
return DBNull.Value;
} 

ldc.i4.s 12
call object [DataRabbit]DataRabbit.DataHelper::GetSafeDbValue(object)

  call object [DataRabbit]DataRabbit.DataHelper::GetSafeDbValue(object)

//获取要赋值的IDataParameter，然后
call valuetype [mscorlib]System.DateTime [mscorlib]System.DateTime::get_Now()
box [mscorlib]System.DateTime
callvirt instance void [System.Data]System.Data.IDataParameter::set_Value(object)