C#泛型类-如何替换值

我在C有点麻烦#

我有一个通用类来处理EntityFramework，如下所示：

public void update(TEntity entity)
{
    try
    {

        using (db = new SystemEntities())
        {
            db.Set<TEntity>().Attach(entity);
            db.Entry(entity).State = EntityState.Modified;
            db.SaveChanges();
        }
    }
    catch (Exception e)
    {
        if (e.GetType() == typeof(DbEntityValidationException))
        {
            DbEntityValidationException error = (DbEntityValidationException)e;

            foreach (var validationErrors in error.EntityValidationErrors)
            {
                foreach (var validationError in validationErrors.ValidationErrors)
                {
                    Log.write(String.Format("Property: {0} Error: {1}", validationError.PropertyName, validationError.ErrorMessage));
                }
            }
        }

        Log.write(e);
    }
}

但c#返回一个异常，表示实体中没有最后一次_更新的定义。我如何解决这个问题？

试试这个：

 PropertyInfo myproperty = typeof(TEntity).GetProperty("last_update");
 if (myproperty != null)
 {
     myproperty.SetValue(entity, DateTime.Now);
 }

    PropertyInfo myproperty = typeof(TEntity).GetProperty("last_update");
    if (myproperty != null)
        myproperty.SetValue(myobj, DateTime.Now);

试试这个：

    PropertyInfo myproperty = typeof(TEntity).GetProperty("last_update");
    if (myproperty != null)
        myproperty.SetValue(myobj, DateTime.Now);

试试这个：

    PropertyInfo myproperty = typeof(TEntity).GetProperty("last_update");
    if (myproperty != null)
        myproperty.SetValue(myobj, DateTime.Now);

试试这个：

    PropertyInfo myproperty = typeof(TEntity).GetProperty("last_update");
    if (myproperty != null)
        myproperty.SetValue(myobj, DateTime.Now);

---

我将在实体级别引入一个接口

public interface IAuditable
{
    public DateTime LastUpdated { get; set; }
}

public class MyEntity : IAuditable
{
    ...
    public DateTime LastUpdated { get; set; }
}

您可以在存储库中对其进行测试

var trackableObj = myobj as IAuditable;
if (trackableObj != null)
    trackableObj.LastUpdated = DateTime.Now;

---

我将在实体级别引入一个接口

public interface IAuditable
{
    public DateTime LastUpdated { get; set; }
}

public class MyEntity : IAuditable
{
    ...
    public DateTime LastUpdated { get; set; }
}

您可以在存储库中对其进行测试

var trackableObj = myobj as IAuditable;
if (trackableObj != null)
    trackableObj.LastUpdated = DateTime.Now;

---

我将在实体级别引入一个接口

public interface IAuditable
{
    public DateTime LastUpdated { get; set; }
}

public class MyEntity : IAuditable
{
    ...
    public DateTime LastUpdated { get; set; }
}

您可以在存储库中对其进行测试

var trackableObj = myobj as IAuditable;
if (trackableObj != null)
    trackableObj.LastUpdated = DateTime.Now;

---

我将在实体级别引入一个接口

public interface IAuditable
{
    public DateTime LastUpdated { get; set; }
}

public class MyEntity : IAuditable
{
    ...
    public DateTime LastUpdated { get; set; }
}

您可以在存储库中对其进行测试

var trackableObj = myobj as IAuditable;
if (trackableObj != null)
    trackableObj.LastUpdated = DateTime.Now;