实体框架 - 如何更新，从键 - 值对的列表领域？ [英] Entity Framework - How to update fields from a list of key-value pairs?

问题描述

假设用户修改自己的包含如名字，姓氏，电子邮件等领域的资料记录。

Let's say the user modifies his profile record that contains fields such as FirstName, LastName, Email, etc.

有关被修改，变更存储为一个键值对的类型的列表中的每个字段：

For each field that is modified, the change is stored as a key-value pair in a list of type:

List<Tuple<string, object>>

在此键值对重$ P $关键psents实际的表列。

The key in this key-value pair represents the actual table column.

在尝试更新记录，这里是如何做这件事的方式：

While trying to update the record, here is one way to do it:

foreach (Tuple<string, object> field in changeList) {
    if (field.Item1.equals("FirstName")) {
        user.FirstName = field.Item2;
    }
    if (field.Item1.equals("Email")) {
       user.Email = field.Item2;
    }
    ...
}

db.SaveChanges()

我想必须有一个更好的方式来做到这一点。

I am thinking there must be a better way to accomplish this.

我想我可以使用反射来对用户设置每个属性

I guess I could use reflection to set each property on the user

foreach(tuple<string, object> field in changeList) {
  user.GetType().InvokeMember(field.Item1,
     BindingFlags.Instance | BindingFlags.Public | BindingFlags.SetProperty,
     Type.DefaultBinder, user, field.Item2);    
}

我想知道是否有更好的方法。也许我可以动态地构建一个变种的对象，也将让我用TryUpdateModel（）方法。

I am wondering if there is even better way. Perhaps I could build a "var" object dynamically that will also let me use TryUpdateModel() method.

推荐答案

我做了类似的事情，但使用string类型和对象的自定义对象。我也不知道这是否是有效率的，但它能够完成任务。为了证明我已经使用元组，其中第一ITEM1是字符串，项目2是一个对象。

I have done something similar but using a custom object of type string and object. I also don't know if this is the efficient one but it gets the job done. To demonstrate I have used Tuple where first item1 is string and item2 is an object.

List<Tuple<string, object>> listTuple = new List<Tuple<string, object>>();

listTuple.Add(new Tuple<string, object>("FirstName", "Foo"));
listTuple.Add(new Tuple<string, object>("LastName", "Bar"));


PropertyInfo[] props = user.GetType().GetProperties();
    foreach (var prop in props)
    {
      if (prop.PropertyType.Name == "ICollection`1")
      {
        //Do not do anything these are navigation properties in entity framework.
        //For eg. If User has Applications then do not set values for Applications.
      }
      else
        {
                //Match each property with matching Item1 in Tuple.
            var myTuple = listTuple.Where(x => x.Item1 == prop.Name).First();
            //Set Users Property using myTuple's Item2 which is an object here. 
            prop.SetValue(user, myTuple.Item2, null);
        }
    }

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