如何检查哪些属性/项被修改的，哪些不是在EF 6编辑记录 [英] How to check that which properties/entries are modified and which are not on Editing a record in EF 6

问题描述

我正在开发使用EF 6.一个MVC 5条申请编辑自动生成的POST方法是：

I am developing an MVC 5 application using EF 6. The auto-generated POST method for Edit is:

public ActionResult Edit([Bind(Include = "Id,Name,Address,Phone,SSNo,D1")] ABC abc)
{
     if (ModelState.IsValid)
     {
         db.Entry(abc).State = EntityState.Modified;
         db.SaveChanges();
     }
     return View(abc);
} 

有任何程序/方法，通过它我可以得到哪些项被修改，哪些是这些条目的原始值。我试图标记为<一个回答方法href=\"http://stackoverflow.com/questions/3265257/getting-all-changes-made-to-an-object-in-the-entity-framework\">this的问题，但虽然已经作了修改它没有得到任何改变，即循环不会迭代。

Is there any procedure/method by which I can get that which entries are modified and what were the original values of those entries. I have tried the method marked as an answer in this question but it didn't get any changes although changes have been made, i.e. the loop does not iterates.

我的code是：

 public ActionResult Edit([Bind(Include = "Id,Name,Address,Phone,SSNo,D1")] ABC abc)
 {
     if (ModelState.IsValid)
     {
          db.ABCs.Attach(abc);
          var myObjectState = ((IObjectContextAdapter)db).ObjectContext.ObjectStateManager.GetObjectStateEntry(abc);
          var modifiedProperties = myObjectState.GetModifiedProperties(); 
          foreach (var propName in modifiedProperties)
          {
                Console.WriteLine("Property {0} changed from {1} to {2}",
                propName,
                myObjectState.OriginalValues[propName],
                myObjectState.CurrentValues[propName]);
          }
          Console.ReadKey();
          db.Entry(abc).State = EntityState.Modified;
          db.SaveChanges();
          return Json(abc);
     }
     return View(abc);
 }

ABC模型包含了比方法的参数中提到的其他许多价值观，但我只有通过那些可编辑

ABC model contains many values other than mentioned in method parameters, but I am only passing those which can be edited

我所要做的是在我的对文档所做的所有更改数据库维护日志。我想只包括在日志中修改前修改和原始值不完整的记录。

What I am trying to do is to maintain a log in my database of all the changes made to a document. I want to include only the changes and the original values before modification in the log not the complete record.

我怎样才能得到呢？

推荐答案

我实现了这个扩展方法适合您：

I implemented this extension method for you:

namespace YourProject.Extensions
{
    public static class ModelExtensions
    {
        public static IEnumerable<KeyValuePair<string, object>> ModifiedValues<T>(this T obj, T modifiedObject) 
        {
            foreach (var property in typeof(T).GetProperties().Where(p => !p.GetGetMethod().IsVirtual))
            {
                if (property.GetValue(obj).ToString() != property.GetValue(modifiedObject).ToString())
                {
                    yield return new KeyValuePair<string, object>(property.Name, property.GetValue(modifiedObject));
                }
            }
        }
    }
}

这是既不是最快，也不是最有效的，但在我的测试工作。

It's neither the fastest nor the most efficient, but worked in my tests.

使用：

var originalEntity = await db.Entities.AsNoTracking().FirstOrDefaultAsync(e => e.EntityId == modifiedEntity.EntityId);
var modifiedValues = originalEntity.ModifiedValues<MyEntity>(modifiedEntity).ToList();

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