Question

我试图理解为什么我的逻辑在将MonitorTag添加到MonitorTag导航属性时没有将实体（NWatchNode）标记为已修改。

以下是代码，我将在下面简要解释：

using (NWatchDbContext context = Application.GetDbContext()) {

    var rootAndChildNodes =
        GetRootAndChildNodesIncludeTags(rootNode, context);
    var uniqueTags = GetUniqueTags(allTags, context);

    var ports = FlattenModelExtendedInfo(routerInfo);

    PerformMonitorTagOperationInternal(tagOper, rootAndChildNodes, uniqueTags, ports);

    // Mark tags as unchanged, otherwise DbContext will
    // create a duplicate.
    MarkTagsUnchanged(context);

    context.SaveChanges();
}

步骤摘要：

获取根节点和子节点，包括他们的MonitorTag。
获取唯一标记（通过查看所有传入的标记以及已由DB Context检索的标记。
获取端口类型（对此问题不重要）
将适当的标签应用于根节点和子节点（如果它们尚未应用它们）
标记标记不变（阻止DbContext考虑分离的标记＆＃34; new＆＃34;，因为我已经知道它们存在于数据库中。
保存更改。

现在，我正在努力解决这个问题： 如果我在MarkTagsUnchanged(context)行上放置断点，则rootAndChildNodes [0]（根节点）已将MonitorTag添加到它的MonitorTag集合中。

但是，在即时窗口中运行context.Entry(rootAndChildNodes[0]).State会返回Unchanged，但我知道在步骤4（PerformMonitorTagOperationInternal(tagOper, rootAndChildNodes, uniqueTags, ports);）添加了MonitorTag

为什么rootAndChildNodes[0]不被视为已修改，即使已将MonitorTag添加到其MonitorTags集合中？

以下是refence的PerformMonitorTagOperationInternal()方法：

private void PerformMonitorTagOperationInternal(TagOperation operation,
    INWatchNodeEntity[] rootAndChildren,
    NWatchMonitorTag[] monTags,
    Dictionary<long, CasApiPortType> ports)
{
    foreach (var node in rootAndChildren) {
        // Check to see if node is Router
        if ((node.NodeType & NetworkDeviceNodeType) > 0) {
            var tag = monTags.
                FirstOrDefault(x => x.Name.Equals(Prefix + NetworkDevicePrefix + node.NodeType,
                StringComparison.CurrentCultureIgnoreCase));

            if (tag != null) {
                PerformTagOperation((NWatchNode)node, tag, operation);
            }
        } else if (node.NodeType == NWatchNodeType.Other) {
            // This would occur if Spectrum has the device as an "SNMP" model class
            var tag = monTags.
                FirstOrDefault(x => x.Name.Equals(Prefix + NetworkDevicePrefix + NWatchNodeType.NetworkL3Switch,
                StringComparison.CurrentCultureIgnoreCase));

            if (tag != null) {
                PerformTagOperation((NWatchNode)node, tag, operation);
            }
        } else if (node.NodeType == NWatchNodeType.NetworkInterface
         && ports.Keys.Contains(node.NativeId)) {

            CasApiPortType portType = ports[node.NativeId];
            if (PortMonitoringTagNamesDictionary.Keys.Contains(portType)) {
                string[] tagNames = PortMonitoringTagNamesDictionary[portType];

                var tags = monTags.
                    Where(x => tagNames.Contains(x.Name)).ToArray();

                foreach (var tag in tags) {
                    PerformTagOperation((NWatchNode)node, tag, operation);
                }
            }
        }
    }
}

以下是PerformTagOperation方法供参考：

private void PerformTagOperation(NWatchNode node, NWatchMonitorTag tag, TagOperation operation)
{
    switch (operation) {
        case TagOperation.AddTag:
            Trace.TraceInformation("Applying tag {0} to {1}.", tag.Name, node.Name);

            if (tag != null && !node.MonitorTags.Contains(tag)) {
                node.MonitorTags.Add(tag);
                Trace.TraceInformation("Applied tag {0} to {1}.", tag.Name, node.Name);
                // Run OnDiscovery for NetworkInterface node time
                if (node.NodeType == NWatchNodeType.NetworkInterface) {
                    Application.Query(new INWatchNode[] { node }, NetworkInterfaceOnDiscoverQuery.AllAttributes);
                } else if (node.NodeType == NWatchNodeType.NetworkRouter || 
                    node.NodeType == NWatchNodeType.NetworkL3Switch ||
                    // Below accounts for Router being defined as SNMP Model Class
                    node.NodeType == NWatchNodeType.Other) {
                    Application.Query(new INWatchNode[] { node }, NetworkRouterOnDiscoverQuery.AllAttributes);
                }
            } else {
                Trace.TraceInformation("Tag {0} is already associated to {1}.", tag.Name, node.Name);
            }
            break;
        case TagOperation.RemoveTag:
            Trace.TraceInformation("Removing tag {0} from {1}.", tag.Name, node.Name);
            if (node.MonitorTags.Contains(tag)) {
                node.MonitorTags.Remove(tag);
                Trace.TraceInformation("Removed tag {0} from {1}.", tag.Name, node.Name);
            } else {
                Trace.TraceInformation("Tag {0} was not associated with {1}.", tag.Name, node.Name);
            }
            break;
    }
}

DbContext未标记实体已修改 - 将MonitorTag添加到节点

0 个答案: