The instance of entity type 'XXX' cannot be tracked because another instance with the same key value for {'XX'} is already being tracked.

在做单元测试的时候碰到以下报错：

The instance of entity type 'XXX' cannot be tracked because another instance with the same key value for {'XX'} is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see the conflicting key values.

具体报错代码如下：

项目平时运行是没问题的，但在单元测试时会报错，可能跟在测试时一个方法里多次调用有关。
我的做法如下：使用try catch，在异常里操作
1、修改状态 Entry (entity).State = EntityState.Detached;
2、再次调用本身

具体代码如下：

public void Detach<T> (T entity) where T : class 
{
    Entry (entity).State = EntityState.Detached;
}

public void EditRange<T> (ICollection<T> entities) where T : class 
{
    Set<T> ().UpdateRange (entities.ToArray ());
}

public virtual void EditRange(ICollection<T> entities, bool again = true)
{
    bool TryAgain = again;
    try
    {
        _dbContext.EditRange(entities);
    }
    catch (Exception ex)
    {
        if (TryAgain)
        {
            foreach (var item in entities)
            {
                Detach(item);
            }
            EditRange(entities, false);
            return;
        }
        throw new Exception(ex.Message);
    }
}