我正在将Silverlight 5
与WCF data service
一起使用,并且已经安装了Silverlight WCF数据服务客户端库。
理想情况下,当我执行DataServiceQuery<T>.BeginExecute
时,回调应在工作线程上返回,但就我而言,它应在UI线程上返回。
为什么让我担心的是我的有效负载非常大,并且需要6-7秒钟左右才能实现对对象的响应(DataServiceQuery<T>.EndExecute method
)。因此,如果它在UI线程上运行,它将阻塞我的UI 6-7秒。
如何在工作线程上获取响应,在工作线程上实现响应,然后切换到UI线程以更新我的UI。
有人遇到过类似的问题吗?
这是我的代码。
private void getRealTimeAssetProfileQuery(Guid assetProfileID, DateTime fromDate, DateTime toDate)
{
dateRanges[assetProfileID].Add(new Range<DateTime>(fromDate, toDate));
context = ServiceAgent.Context;
var qry = (from o in context.RealTimeProfilePoint
where o.ProfileID == assetProfileID && o.PointTime >= fromDate && o.PointTime <= toDate
orderby o.PointTime descending
select o) as DataServiceQuery<RealTimeProfilePoint>;
qry = qry.AddQueryOption("$expand", "Profile");
qry = qry.AddQueryOption("$expand", "Profile/ProfileType");
dynamic asyncState = new
{
assetProfileID = assetProfileID,
fromDate = fromDate,
toDate = toDate
};
Uri qryUri = new Uri(qry.ToString());
context.BeginExecute<RealTimeProfilePoint>(qryUri, new AsyncCallback(realTimeCallBack), asyncState);
}
void realTimeCallBack(IAsyncResult asyncResult)
{
if (Deployment.Current.Dispatcher.CheckAccess())
raiseTrace("Data Service Response On UI Thread \n");
else
raiseTrace("Data Service Response On worker Thread \n");
dynamic asyncState = asyncResult.AsyncState as dynamic;
Guid assetProfileID = asyncState.assetProfileID;
DateTime fromDate = asyncState.fromDate;
DateTime toDate = asyncState.toDate;
IEnumerable<RealTimeProfilePoint> profilePoints = context.EndExecute<RealTimeProfilePoint>(asyncResult);
List<RealTimeProfilePoint> lstProfilePoint = profilePoints.ToList();
if (((QueryOperationResponse)profilePoints).GetContinuation() != null)
{
Uri qryUri = ((QueryOperationResponse)profilePoints).GetContinuation().NextLinkUri;
context.BeginExecute<RealTimeProfilePoint>(qryUri, new AsyncCallback(realTimeCallBack), asyncState);
}
if (lstProfilePoint.Count > 0)
{
var assetProfile = lstProfilePoint[0].Profile;
Instance.addRealTimePoints(assetProfile, lstProfilePoint);
raiseTrace(
"Fetching Real Time Profile Points from Server for AssetProfileID " +
assetProfileID.ToString() + " : " +
lstProfilePoint.Count.ToString() + " record(s) found for" +
fromDate.ToUtcTime().ToString() + " - " + toDate.ToUtcTime().ToString() +
" peiod.");
}
}
最佳答案
从(后台)线程启动您的请求。
dynamic asyncState = new
{
assetProfileID = assetProfileID,
fromDate = fromDate,
toDate = toDate,
uiDispatcher = Application.Current.MainWindow.Dispatcher, // for gui access on background thread
};
new Thread(() =>
{
context.BeginExecute<RealTimeProfilePoint>(qryUri, new AsyncCallback(realTimeCallBack), asyncState);
})
{
IsBackground = true,
}
.Start();
关于multithreading - Silverlight WCF数据服务回调在UI线程上返回,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/19787105/