Question

假设我有天数列表：

太阳 - 1
周一 - 2
星期二 - 4
周三 - 8
周四 - 16
周五 - 32
周六 - 64

现在用户可以从清单中选择一个或多个。我的数据库只存储天数（例如：如果用户选择了sun和mon，则值存储在数据库中是3）。现在我要显示用户天数他选择了。计算这个的公式是什么。

我应该为此写一个二进制逻辑吗？

Answer 1

为工作日创建Flags枚举，将其视为位字段：

[Flags]
public enum WeekDays
{
   Sun = 1,
   Mon = 2,
   Tue = 4,
   Wed = 8,
   Thu = 16,
   Fri = 32,
   Sat = 64
}

然后保存到数据库

WeekDays value = WeekDays.Sun | WeekDays.Mon; // Sun, Mon

从数据库中读取时，使用HasFlag方法验证值是否包含给定的工作日（如果给定位字段在枚举值中设置）：

WeekDays value = ReadValueFromDatabase();

foreach(WeekDays day in Enum.GetValues(typeof(WeekDays)))
{
    if (value.HasFlag(day))
       // day is selected
}

这与按位操作的用法相同：

(value & day) == day

Answer 2

试试这个：

[Flags]
public enum Day
{

    Sunday = 1,
    Monday = 2,
    Tuesday = 4,
    Wednesday = 8,
    Thursday = 16,
    Friday = 32,
    Saturday = 64,
}

Day d = Day.Friday | Day.Saturday;

Console.WriteLine(d);
Console.WriteLine((int)d);

这打印：星期五，星期六和96

谢尔盖刚刚在我面前张贴的......

Answer 3

创建一个程序，从数据库中获取剩余的总和

<pre>
private int GetRemainder(int DaySum)
{
    int xRemainder = 0;

    if(DaySum > 64)
        xRemainder = DaySum % 64;
    else if(DaySum > 32)
        xRemainder = DaySum % 32;
    else if(DaySum > 16)
        xRemainder = DaySum % 16;
    else if(DaySum > 8)
        xRemainder = DaySum % 8;
    else if(DaySum > 4)
        xRemainder = DaySum % 4;
    else if(DaySum > 2)
        xRemainder = DaySum % 2;
    else if(DaySum > 1)
        xRemainder = DaySum % 1;

    return xRemainder;
}
private string SelectedDay(int SumValue)
{
    if((SumValue/64) > 0)
        return "Saturday";
    else if((SumValue/32) > 0)
       return "Friday";
    else if((SumValue/16) > 0)
        return "Thursday";
    else if((SumValue/8) > 0)
        return "Wednesday";
    else if((SumValue/4) > 0)
        return "Tuesday";
    else if((SumValue/2) > 0)
        return "Monday";
    else if((SumValue/1) > 0)
        return "Sunday";
}
</pre>

有变量来存储值

<pre>
int SumOfDaysSelected = 0;
string DaysSelected = "";
</pre>

然后创建条件以检查根据变量SumOfDaysSelected的值选择的日期或天数

<pre>
while(SumOfDaysSelected > 0)
{
if(DaysSelected == "")
    DaysSelected = SelectedDay(SumOfDaysSelected);
else
    DaysSelected = DaysSelected + "," + SelectedDay(SumOfDaysSelected);

SumOfDaysSelected = GetRemainder(SumOfDaysSelected);
}
</pre>

根据DaysLIST的值总和获取天数

3 个答案: