小编cho*_*bo2的帖子

我开始使用泛型,并且无法真正找到简单的初学者指南,所以我只是在做试验和错误.

我想转换它

public void CreateTask(Task task, Student student)
{
            Task convertToUtcTime = task.ConvertToUtcTime(student);
            session.Save(convertToUtcTime);
}


public static Task ConvertToUtcTime(this Task task, Student student)
{
    if (student != null)
    {
        TimeZoneInfo info = TimeZoneInfo.FindSystemTimeZoneById(student.TimeZoneId);
        task.DueDate = TimeZoneInfo.ConvertTimeToUtc(task.DueDate, info);
    }

    return task;
}

是通用的

我开始尝试这个(我还没有遵守它,所以这可能不起作用)

  public void Create<T>(T entity, Student student)
    {
                T convertToUtcTime = entity.ConvertToUtcTime(student);
                session.Save(convertToUtcTime);
    }


  public static T ConvertToUtcTime(this T entity, Student student)
    {
        if (student != null)
        {
            TimeZoneInfo info = TimeZoneInfo.FindSystemTimeZoneById(student.TimeZoneId);
            entity.DueDate = TimeZoneInfo.ConvertTimeToUtc(entity.DueDate, info);
        }

        return …

我正在考虑为我的权限类型创建一个枚举,而不是将它们全部存储为db中的true或false值.

class Program
{
    static void Main(string[] args)
    {
        Test addEdit = Test.AddEdit;
        bool hasEdit = addEdit.HasFlag(Test.Edit);
        bool hasAdd = addEdit.HasFlag(Test.Add);
        bool hasDelete = addEdit.HasFlag(Test.Delete);
        Console.WriteLine(hasEdit);
        Console.WriteLine(hasAdd);
        Console.WriteLine(hasDelete);
        Console.Read();
    }
}

   [Flags]
    public enum Test
    {
        Add = 0,
        Edit = 1,
        Delete = 2,
        AddEdit = Add | Edit
    }

所以我做到了这一点.我发现有趣的是addEdit varaible在通过VS调试器查看时只显示"Edit"的值.起初我以为它没有存储这两个值.

我使用了hasFlag方法,当然它知道这两个值.

这是一个错误还是什么？

说我有这个硬编码的代码,

$("#test").gmap3({
  map:{
    options:{
      center:{lat:24.886436490787712,lng:-70.2685546875},
      zoom:3,
      mapTypeId: google.maps.MapTypeId.TERRAIN
    }
  },
  polygon: {
    values: [
      {
        options:{
          strokeColor: "#FF0000",
          strokeOpacity: 0.8,
          strokeWeight: 2,
          fillColor: "#FF0000",
          fillOpacity: 0.35,
          paths:[
            [25.774252, -80.190262],
            [18.466465, -66.118292],
            [32.321384, -64.75737],
            [25.774252, -80.190262]
          ]
        }
      },
      {
        options:{
          strokeColor: "#FF0000",
          strokeOpacity: 0.8,
          strokeWeight: 2,
          fillColor: "#FF0000",
          fillOpacity: 0.35,
          paths:[
            [37.33522435930639,-97.7783203125],
            [37.33522435930639,-85.8251953125],
            [29.420460341013133,-86.3525390625],
            [23.120153621695614,-97.0751953125]
          ]
        }
      },
      {
        options:{
          strokeColor: "#FF0000",
          strokeOpacity: 0.8,
          strokeWeight: 2,
          fillColor: "#FF0000",
          fillOpacity: 0.35,
          paths:[
            [21.002471054356725,-52.4267578125],
            [28.34306490482549,-47.1533203125],
            [17.35063837604883,-35.7275390625],
            [11.049038346537106,-49.0869140625],
            [8.276727101164045,-61.2158203125]
          ]
        }
      },
    ], …

如果我有学生和课程的经典例子,请说.学生可以有很多课程,课程可以有很多学生.

如果我想在许多表格部分添加额外的字段,如何在EF 6代码中创建中间表？

我只是在代码中创建另一个类,然后以某种方式将其挂起？

DB上下文

public class MyContext : DbContext
{
    public MyContext (string nameOrConnectionString) : base(nameOrConnectionString)
    {
        // this.Configuration.ProxyCreationEnabled = false;
        Database.SetInitializer(new CreateDatabaseIfNotExists<OSPContext>());
    }

    public DbSet<Student> Students { get; set; }
    public DbSet<Course> Courses { get; set; }

    public DbSet<StudentCourse> StudentCourses { get; set; }

}


public class StudentCourse
{
    [Key]
    public Guid StudentCourseId { get; set; }

    public Guid StudentId { get; set; }

    [ForeignKey("StudentId")]
    public virtual Student Student { get; set; } // Include this so you …

我想在最后一步显示一个“完成”按钮。我正在使用jquery 智能向导。

我没有看到任何内置方法来确定我是否处于最后一步？我错过了什么吗？

$(文档).ready(函数(){

  // Toolbar extra buttons
  var btnFinish = $('<button></button>').text('Finish')
                                   .addClass('btn btn-info')
                                   .on('click', function(){ alert('Finish Clicked'); });
  var btnCancel = $('<button></button>').text('Cancel')
                                   .addClass('btn btn-danger')
                                   .on('click', function(){ $('#smartwizard').smartWizard("reset"); });

  // Step show event
  $("#smartwizard").on("showStep", function(e, anchorObject, stepNumber, stepDirection, stepPosition) {
      $("#prev-btn").removeClass('disabled');
      $("#next-btn").removeClass('disabled');
      if(stepPosition === 'first') {
          $("#prev-btn").addClass('disabled');
      } else if(stepPosition === 'last') {
          $("#next-btn").addClass('disabled');
      } else {
          $("#prev-btn").removeClass('disabled');
          $("#next-btn").removeClass('disabled');
      }
  });

  // Smart Wizard
  $('#smartwizard').smartWizard({
      selected: 0,
      theme: 'arrows',
      transition: {
          animation: 'slide-horizontal', // Effect on navigation, none/fade/slide-horizontal/slide-vertical/slide-swing …

我有一个foreach循环,它第一次在它工作的第一个项目中找到但是当它到达下一个项目时,我得到了这个错误.

System.InvalidOperationException
  HResult=0x80131509
  Message=Error generated for warning 'Microsoft.EntityFrameworkCore.Infrastructure.LazyLoadOnDisposedContextWarning: An attempt was made to lazy-load navigation property 'Company' on entity type 'RecurringInvoiceTemplateProxy' after the associated DbContext was disposed.'. This exception can be suppressed or logged by passing event ID 'CoreEventId.LazyLoadOnDisposedContextWarning' to the 'ConfigureWarnings' method in 'DbContext.OnConfiguring' or 'AddDbContext'.
  Source=Microsoft.EntityFrameworkCore
  StackTrace:
   at Microsoft.EntityFrameworkCore.Diagnostics.EventDefinition`2.Log[TLoggerCategory](IDiagnosticsLogger`1 logger, WarningBehavior warningBehavior, TParam1 arg1, TParam2 arg2, Exception exception)
   at Microsoft.EntityFrameworkCore.Internal.CoreLoggerExtensions.LazyLoadOnDisposedContextWarning(IDiagnosticsLogger`1 diagnostics, DbContext context, Object entityType, String navigationName)
   at Microsoft.EntityFrameworkCore.Internal.LazyLoader.ShouldLoad(Object entity, String navigationName, NavigationEntry& navigationEntry)
   at Microsoft.EntityFrameworkCore.Internal.LazyLoader.Load(Object entity, String …