ServerDiscovery QML Type
提供有关可用服务器的信息。更多
Import Statement: | import QtOpcUa |
Since: | QtOpcUa 5.13 |
Status: | Deprecated since 6.9 |
自 QtOpcUa 6.9 起,该类型已被弃用。我们强烈建议不要在新代码中使用它。
属性
- connection : Connection
- count : int
- discoveryUrl : string
- status : Status
方法
- ApplicationDescription at(index)
详细说明
允许获取和访问服务器或发现服务器已知服务器的信息。
QtOpcUa.Connection { id: connection backend: availableBackends[0] defaultConnection: true } QtOpcUa.ServerDiscovery { discoveryUrl: "opc.tcp://127.0.0.1:43344" onServersChanged: { if (status.isGood) { if (status.status == QtOpcUa.Status.GoodCompletesAsynchronusly) return; // wait until finished if (count > 0) { // choose right server endpointDiscovery.serverUrl = at(0).discoveryUrls[0]; console.log("Using server URL:", endpointDiscovery.serverUrl); } else { // no servers retrieved } } else { // Fetching servers failed console.log("Error fetching server:", servers.status.status); } } } QtOpcUa.EndpointDiscovery { id: endpointDiscovery onEndpointsChanged: { if (status.isGood) { if (status.status == QtOpcUa.Status.GoodCompletesAsynchronusly) return; // wait until finished if (count > 0) { // choose right endpoint console.log("Using endpoint", at(0).endpointUrl, at(0).securityPolicy); connection.connectToEndpoint(at(0)); } else { // no endpoints retrieved } } else { // Fetching endpoints failed console.log("Error fetching endpoints:", status.status); } } }
属性 文档
connection : Connection |
discoveryUrl : string |
要检索服务器列表的服务器的 URL。每更改一次 URL,就会启动一次对给定服务器的请求。
启动请求时,可用服务器列表将被清空,状态设为Status.GoodCompletesAsynchronously 。请求完成后,status 。访问服务器列表前,请务必检查status 。
onServersChanged: { if (status.isGood) { if (status.status == QtOpcUa.Status.GoodCompletesAsynchronusly) return; // wait until finished if (count > 0) { var serverUrl = at(0).serverUrl(); console.log(serverUrl); } } else { // handle error } }
另请参阅 ApplicationDescription,status,at,count 和Status 。
status : Status |
该元素的当前状态。如果上次服务器检索成功,则状态应为Status.Good
。
if (status.isGood) { // Choose endpoint to connect to } else { // handle error }
另请参见 Status 。
方法文档
ApplicationDescription at(index) |
返回给定index 上的应用程序描述。如果没有可用的服务器或索引无效,则返回无效的应用程序说明。在使用任何返回的数据之前,应检查status 是否成功检索到信息。
if (servers.status.isGood) { if (servers.count > 0) var serverUrl = at(0).serverUrl(); console.log(serverUrl); // Choose endpoint to connect to } else { // handle error }
另请参阅 count,status, 和ApplicationDescription 。
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