asp.net-mvc – 如何在实体框架中为GUID设置NewId()

我正在创建asp.net mvc4示例.在此我创建了ID列作为GUID在表格的datacontext.

public class Sample
{
    [required]
    public Guid ID { get; set; }
    [required]
    public string FirstName { get; set; }
}

这是实体表

CreateTable(
"dbo.Samples",c => new
 {
     ID = c.Guid(nullable: false),FirstName = c.String(nullable: false)                   
 })
 .PrimaryKey(t => t.ID);

Id通过00000000-0000-0000-0000-000000000000.

如何将newid()设置为GUID以及我必须设置的位置.

解决方法

我建议只使用长时间的ID类型.它与“GUID”相匹配,并具有一定的性能提升.但是,如果要使用GUID,您应该使用 Sequential GUID并将其设置在构造函数中.我也会将ID设为私人设定者：

public class Sample
{
    public Sample() {
        ID = GuidComb.Generate();
    }
    [required]
    public Guid ID { get; private set; }
    [required]
    public string FirstName { get; set; }
}

顺序GUID

public static class GuidComb
    {
        public static Guid Generate()
        {
            var buffer = Guid.NewGuid().ToByteArray();

            var time = new DateTime(0x76c,1,1);
            var Now = DateTime.Now;
            var span = new TimeSpan(Now.Ticks - time.Ticks);
            var timeOfDay = Now.TimeOfDay;

            var bytes = BitConverter.GetBytes(span.Days);
            var array = BitConverter.GetBytes(
                (long)(timeOfDay.TotalMilliseconds / 3.333333));

            Array.Reverse(bytes);
            Array.Reverse(array);
            Array.copy(bytes,bytes.Length - 2,buffer,buffer.Length - 6,2);
            Array.copy(array,array.Length - 4,buffer.Length - 4,4);

            return new Guid(buffer);
        }
    }