DbContext持久化与静态方法基于控制台应用程序管理员用户选择 [英] DbContext persistence with static method based on console application admin user selection

问题描述

我有一个 DbContext 类，只要控制台应用程序正在运行，我只想将适当的环境连接字符串设置一次。

  public class RPMContext：DbContext {
 public RPMContext（string nameOrConnectionString）
：base（nameOrConnectionString）{
} 
} 
  

然后它将被调用

  private RPMContext db = new RPMContext（name = LH_RPMContext）; 
  

然而，我需要持久化一个静态的全局方法，以便我可以依赖于运行控制台应用程序的生命周期不会消失

我正在使用这样的菜单系统

  Console.WriteLine（Select Environment：\\\
）; 
 Console.WriteLine（1。Localhost）; 
 Console.WriteLine（2。DEV）; 
 Console.WriteLine（3。QA）; 
 Console.WriteLine（4。Day 1）; 
 Console.WriteLine（5。Production\\\
）; 
 Console.Write（Number：）; 
 byte environment = byte.Parse（Console.ReadLine（））; 
  

所以我想如果用户选择了 2 这是DEV，然后

  var dev_db = new RPMContext（name = DEV_RPMContext）; 
  

不过之后，当我使用Entity Framework进行各种CRUD操作时，我将要实例化再次...所以我只想在记忆中保持这个值，对吧？

所以也许一些枚举这些值如 DEV_RPMContext 然后设置它？

这是我的另一个问题：将字符串传递给具有Base类的DbContext的构造方法未设置值

解决方案

一个选项是编辑您的DbContext模板，如下所示：

  public class RPMContext：DbContext {
 public static string DefaultConnectionString; 
 public RPMContext（）：base（DefaultConnectionString）{
} 
 public RPMContext（string nameOrConnectionString）
：base（nameOrConnectionString）{
} 
} 
  

然后当选择时，分配所选的连接字符串：

  RPMContext.DefaultConnectionString =你的连接字符串; 
  

然后只是像往常一样实例化上下文：

  using（var ctx = new RPMContext（））{
 //在此使用默认连接字符串
} 
  / pre> 
I have a DbContext class in which I want to set the proper environment connection string only once as long as the console application is running.
public class RPMContext : DbContext {    
    public RPMContext(string nameOrConnectionString)
        :base(nameOrConnectionString) {
    }  
}
Then it would be called up with 
 private RPMContext db = new RPMContext("name=LH_RPMContext");
However I need to persist a static global method of this so that I can count on the persistence of the lifetime of the running console application that it does not go away

I was having a menu system like this 
 Console.WriteLine("Select Environment:\n");
 Console.WriteLine("1. Localhost");
 Console.WriteLine("2. DEV");
 Console.WriteLine("3. QA");
 Console.WriteLine("4. Day 1");
 Console.WriteLine("5. Production\n");
 Console.Write("Number: ");
 byte environment = byte.Parse(Console.ReadLine());
So I suppose that if the user picked 2 which is "DEV" then 
 var dev_db = new RPMContext("name=DEV_RPMContext");
However later on when I am doing all sorts of CRUD operations with Entity Framework,  I will want to instantiate it again ... so thus I will just want to hold that value in memory then, right?

So maybe some enum with these values like DEV_RPMContext and then set it ? 

Here was my other question: Passing string into a Constructor of DbContext with a Base class is not setting the value
解决方案
One option is to edit your DbContext template like this:
public class RPMContext : DbContext {
    public static string DefaultConnectionString;
    public RPMContext():base(DefaultConnectionString) {
    }   
    public RPMContext(string nameOrConnectionString)
        :base(nameOrConnectionString) {
    }  
}
Then when choice is made, assign selected connection string:
RPMContext.DefaultConnectionString = "your connection string";
And then just instantiate context as usual:
using (var ctx = new RPMContext()) {
// uses default connection string here
}


                        
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