InvalidOperationException - 帮助!!! [英] InvalidOperationException - Help!!!

问题描述

您好！

我收到以下错误：
对象处于分离状态。分离对象时，无法在ObjectStateEntry上执行此操作。

当我尝试此操作时：

受保护 覆盖 void Dispose（ bool disposing）
{
foreach （ var 条目 in ObjectStateManager.GetObjectStateEntries（ EntityState .Added | EntityState 。删除| EntityState .Modified | EntityState .Unchanged））
{
if （条目。实体！= null ）< - - 这是我得到错误的地方
{
Detach（entry.Entity）;
}


base .Dispose（disposing）;



我在这里找到了这个简单的代码论坛，因为即使在处理了上下文之后，实体仍然依附于它。
它工作正常，直到我需要这样做：

public 列表 < Period > GetPeriod（ string model， string company）
{
<使用 （ 实体 context = new 实体 （））
{
返回 Period .ReadPeriod（context，model，company）;
}< - 这里调用dispose

}

public static List < Period > ReadPeriod（ 实体 context， string modelName， string company）
{
var query = from p < font color ="＃0000ff"size = 2> in context.Periods
join m in context.Models 上 p.Models.ID 等于 m.ID
join <字体大小= 2> c in context .Companies on p.Companies.ID equals c.ID
其中 m.Name == modelName& &安培; c.Name == company
选择 p;
return query.ToList< Period >（ ）;
}

如果我删除了要处置的覆盖，它可以工作，但旧问题会在以后再次出现。
那么......我该怎么做才能避免这种情况？

解决方案

Marco，

显然你不需要分离它已分离。
因此你只需要在分离之前添加另一个检查即


if （（entry.EntityState& ; EntityState.Detached）！= EntityState.Detached&& entry.Entity！= null ）< - --thi s是我得到错误的地方
{
Detach（entry.Entity）;
}

然后，如果EntityState被分离则会抛出entry.Entity中的Validation逻辑发生。结果，干杯结果亚历

Hello!

I get the following error:
The object is in a detached state. This operation cannot be performed on an ObjectStateEntry when the object is detached.

when i try this:

protected override void Dispose(bool disposing)
{
    foreach (var entry in ObjectStateManager.GetObjectStateEntries(EntityState.Added | EntityState.Deleted | EntityState.Modified | EntityState.Unchanged))
    {
        if (entry.Entity != null) <---this is where i get the error
        {
            Detach(entry.Entity);
        }
    }
    base.Dispose(disposing);
}

I found this simple code here on the forum, because even after disposing the context, entities still remain attached to it.
It worked fine till i needed to do this:

public List<Period> GetPeriod(string model, string company)
{
    using (Entities context = new Entities())
    {
        return Period.ReadPeriod(context, model, company);
    }<-- here where dispose is called
}

public static List<Period> ReadPeriod(Entities context, string modelName, string company)
{
    var query = from p in context.Periods
                    join m in context.Models on p.Models.ID equals m.ID
                    join c in context.Companies on p.Companies.ID equals c.ID
                    where m.Name == modelName && c.Name == company
                    select p;
     return query.ToList<Period>();
}

If i delete the override to dispose, it works, but the old problem appears again later.
So...what can i do to avoid this?

解决方案

Marco,

Obviously you don't need to Detach if it is already Detached.
Hence you just need to add another check before Detaching i.e.

        if ((entry.EntityState & EntityState.Detached) != EntityState.Detached && entry.Entity != null ) <---this is where i get the error
        {
            Detach(entry.Entity);
        }

And then the Validation logic inside entry.Entity which throws if the EntityState is Detached doesn't happen.
Cheers
Alex

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