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C# ObjectStateManager.TryGetObjectStateEntry方法代码示例

本文整理汇总了C#中System.Data.Objects.ObjectStateManager.TryGetObjectStateEntry方法的典型用法代码示例。如果您正苦于以下问题:C# ObjectStateManager.TryGetObjectStateEntry方法的具体用法?C# ObjectStateManager.TryGetObjectStateEntry怎么用?C# ObjectStateManager.TryGetObjectStateEntry使用的例子?那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在System.Data.Objects.ObjectStateManager的用法示例。


在下文中一共展示了ObjectStateManager.TryGetObjectStateEntry方法的2个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C#代码示例。

示例1: using

int orderId = 43680;

using (AdventureWorksEntities context =
    new AdventureWorksEntities())
{
    ObjectStateManager objectStateManager = context.ObjectStateManager;
    ObjectStateEntry stateEntry = null;

    var order = (from o in context.SalesOrderHeaders
                 where o.SalesOrderID == orderId
                 select o).First();

    // Attempts to retrieve ObjectStateEntry for the given EntityKey.
    bool isPresent = objectStateManager.TryGetObjectStateEntry(((IEntityWithKey)order).EntityKey, out stateEntry);
    if (isPresent)
    {
        Console.WriteLine("The entity was found");
    }
}
开发者ID:.NET开发者,项目名称:System.Data.Objects,代码行数:19,代码来源:ObjectStateManager.TryGetObjectStateEntry

示例2: ApplyItemUpdates

private static void ApplyItemUpdates(SalesOrderDetail originalItem,
    SalesOrderDetail updatedItem)
{
    using (AdventureWorksEntities context =
        new AdventureWorksEntities())
    {
        context.SalesOrderDetails.Attach(updatedItem);
        // Check if the ID is 0, if it is the item is new. 
        // In this case we need to chage the state to Added.
        if (updatedItem.SalesOrderDetailID == 0)
        {
            // Because the ID is generated by the database we do not need to
            // set updatedItem.SalesOrderDetailID.
            context.ObjectStateManager.ChangeObjectState(updatedItem, System.Data.EntityState.Added);
        }
        else
        {
            // If the SalesOrderDetailID is not 0, then the item is not new
            // and needs to be updated. Because we already added the 
            // updated object to the context we need to apply the original values.
            // If we attached originalItem to the context 
            // we would need to apply the current values:
            // context.ApplyCurrentValues("SalesOrderDetails", updatedItem);
            // Applying current or original values, changes the state 
            // of the attached object to Modified.
            context.ApplyOriginalValues("SalesOrderDetails", originalItem);
        }
        context.SaveChanges();
    }
}
开发者ID:.NET开发者,项目名称:System.Data.Objects,代码行数:30,代码来源:ObjectStateManager.TryGetObjectStateEntry


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