问题描述
我正在实现一个Singleton Repository类，其中包含打开和关闭每个调用的datacontext所需的方法。我将主要应用程序中的这些方法称为：
`MyTemplate tmp1 = Repository.Instance.Function1（10）;`
I am implementing a Singleton Repository class with methods that are required to open and dismiss the datacontext for every call. I call these methods from the main application as:
`MyTemplate tmp1 = Repository.Instance.Function1 (10);`
最后，我想要一个Save方法来保存一个新的"MyTemplate"。如何使用我的设计所基于的格式？
Somewhere at the end, I want to have a Save method to save a new "MyTemplate". How is that done with the format my design is based on?
tmp1.property1 ="更改为其他内容";
tmp1.property10 ="已更改"; // ....以及此处附带的许多复杂属性
tmp1.property1 = "change to something else";
tmp1.property10 = "changed"; // .... and many complicated properties attached here
Repository.Instance.Save（TMP1）;  //需要帮助实现！
Repository.Instance.Save(tmp1); // Need help implementing!
我也试过"Detach（）"在线示例以及"克隆"，但似乎没有什么对我有用。
I also have tried "Detach()" examples online as well as "Cloning", but nothing seem to work for me.
请注意我应该保留此设计，因此全局Datacontext等选项无效。表格"MyTemplate"有一个非常复杂的长
属性列表，所以它不像使用2个属性或复制/克隆模板那么容易。
Please be advised I am supposed to keep this design, so options like global Datacontext is not valid. The table "MyTemplate" has a very complicated long
list of properties so it's not as easy as working with 2 properties or copying/cloning the template.
   public sealed class Repository：IRepository，IDisposable
{
private static readonly Repository _instance = new Repository（）;
public sealed class Repository: IRepository, IDisposable
{
private static readonly Repository _instance = new Repository();
public static Repository Instance {get {return _instance; }
private Repository（）{} //构造函数
static Repository（）{}
public static Repository Instance { get { return _instance; } }
private Repository() { } // Constructors
static Repository() { }
// IRepository会员示例：
public MyTemplate Function1（int i）
{  //打开并关闭¥b $ b DataContext db = new DataContext（@" ...."）;
return db.mytemplates.where（x => x.Id == i）.FirstOrDefault（）;
}
public MyTemplate Function2（）
{  //打开并关闭¥b $ b DataContext db = new DataContext（@" ...."）;
return db.someothercommand .....
}
// IRepository member examples:
public MyTemplate Function1(int i)
{ // Open and dismiss
DataContext db = new DataContext(@"....");
return db.mytemplates.where(x => x.Id == i).FirstOrDefault();
}
public MyTemplate Function2()
{ // Open and dismiss
DataContext db = new DataContext(@"....");
return db.someothercommand.....
}
//需要在这里提供帮助：
$
public Save（MyTemplate templateToSave）{
// NEED HELP HERE:
public Save (MyTemplate templateToSave) {
//我尝试了以下内容：
$
//   克隆不起作用
//   创建Partial类并实现Detach（）不起作用。
// I have tried the following:
// Cloning didn't work
// Created Partial class and implemented Detach() didn't work.
// 试过：
//  db.MyTemplates.Attach（templateToSave）;
//  db.SubmitChanges（）;
} b $ b}
// Tried:
// db.MyTemplates.Attach(templateToSave);
// db.SubmitChanges();
}
}
真的很感激任何帮助。我现在一直在尝试不同的方法。
Any help would really be appreciated. I have been trying different approaches for days now.
谢谢。
推荐答案
// IRepository member examples:
public MyTemplate Function1(int i)
{ // Open and dismiss
DataContext db = new DataContext(@"....");
var myTemplate = db.mytemplates.where(x => x.Id == i).FirstOrDefault();
// This wwill detache the entity from the context.
db.Entry(myTemplate).State = EntityState.Detached;
return myTemplate;
}
// A generic method to handle attaching and saving changes to the db.
public void Save<T>(T templateToSave) where T : class
{
DataContext db = new DataContext(@"....");
db.Set<T>().Attach(templateToSave);
db.Entry(templateToSave).State = EntityState.Modified;
db.SaveChanges();
}要调用Save函数，您需要传递要用作T参数的表，如下所示
To call the Save function you need to pass the table you wish to use as the T parameter, something like this
Save<MyTemplates>(templateToSave);
这篇关于如何使用Singleton Repository将Result或SubmitChanges附加到DataContext的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！