如何在接口中实现Delete方法并在Controller MVC4中调用答案

【问题标题】：How to implement the Delete method in the interface and call it in the Controller MVC4如何在接口中实现Delete方法并在Controller MVC4中调用
【发布时间】：2014-09-29 08:06:42
【问题描述】：

您好，我想在我的 DataSource 中实现我的 void Delete 方法。我创建了 Save() 方法，但在使用 Delete() 时遇到了困难。我一直在寻找，但仍然不知道该怎么做。任何帮助。

界面：

 public  interface IDepartmentDataSource
{
    IQueryable<User> Users { get; }
    IQueryable<Department> Departments { get;}
    IQueryable<Entry> Entries { get; }

    void Delete();
    void Save();

}

数据源：

  public class DepartmentDb : DbContext, IDepartmentDataSource
{
    public DepartmentDb() : base("DefaultConnection")
    {

    }

    public DbSet<User> Users { get; set; }
    public DbSet<Department> Departments { get; set; }
    public DbSet<Entry> Entries { get; set; }


    void IDepartmentDataSource.Save()
    {
        SaveChanges();  
    }

    void IDepartmentDataSource.Delete()
    {

        // What is the logic here?

    }

    IQueryable<Entry> IDepartmentDataSource.Entries
    {
        get { return Entries; }
    }

    IQueryable<Department> IDepartmentDataSource.Departments
    {
        get { return Departments; }
    }

    IQueryable<User> IDepartmentDataSource.Users
    {
        get { return Users; }
    }
}

【问题讨论】：

标签： c# asp.net-mvc-4 entity-framework-5

【解决方案1】：

我认为你需要类似的东西：

public void IDepartmentDataSource.DeleteDepartment(int id)
{

   Department itemToDelete = this.GetDepartmentById(id);
   if (itemToDelete != null)
   {
     this.Departments.Remove(itemToDelete);                
   }

 }

（请参阅here 了解 GetDepartmentById 方法...）

【讨论】：

【解决方案2】：

我找到了解决方案。我遇到的问题是存储库模式。现在我的代码看起来像：

public class DepartmentDb : DbContext
{
public DepartmentDb() : base("DefaultConnection")
{

}

public DbSet<User> Users { get; set; }
public DbSet<Department> Departments { get; set; }
public DbSet<Entry> Entries { get; set; }

}

// your repository
public class DepartmentRepository: IDisposable
{
protected bool isDisposed = false;
private DepartmentDb Context { get; set; } 

// read (public)
public IQueryable<user> Users { get { return Context.Users; } }
public IQueryable<department> Departments { get { return Context.Departments; } }
public IQueryable<entry> Entries { get { return Context.Entries; } }

public DepartmentRepository() 
{
     Context = new DepartmentDb();
}

public int Insert(User item)
{ 
    Context.Users.Add(item);
    return Context.SaveChanges();
}

public int Update(User item)
{ 
    Context.Entry<user>(item).State = EntityState.Modified;
    return Context.SaveChanges();
}


public int Delete(User item)
{ 
    Context.Users.Remove(item);
    return Context.SaveChanges();
}

protected virtual void Dispose(bool disposing)
{
if (isDisposed)
    return;

if (disposing)
{
    if (this.Context != null)
    {
        this.Context.Dispose();
        this.Context = null;
    }
}

isDisposed = true;
}

public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}   

}

【讨论】：