I am calling a async method having a single parameter, It will return me the result according to parameter. I am calling that method more than one time with different parameter value, but in Completed event i am getting the same value for all.
client.ListAllLookupValuesByTypeCompleted += client_ListAllAddressFormatCompleted;
client.ListAllLookupValuesByTypeAsync("AddressFormat");
client.ListAllLookupValuesByTypeCompleted += client_ListAllPhoneFormatCompleted;
client.ListAllLookupValuesByTypeAsync("PhoneFormat");
void client_ListAllAddressFormatCompleted(object sender, ListAllLookupValuesByTypeCompletedEventArgs e)
{
cmbAddressFormat.ItemsSource = e.Result;
}
void client_ListAllPhoneFormatCompleted(object sender, ListAllLookupValuesByTypeCompletedEventArgs e)
{
cmbPhonePrintFormat.ItemsSource = e.Result;
}
But getting same value in e.Result.
any suggetions. Thanks.
Your method may return a different value based on the first parameter, but both handlers will be called at the same time every time, regardless of what you send it. If this is a standard webservice reference, then you should see an object userState parameter available for you and this can be used to determine what to do.
client.ListAllLookupValuesByTypeCompleted += client_ListAllLookupValuesCompleted;
client.ListAllLookupValuesByTypeAsync("AddressFormat", true);
client.ListAllLookupValuesByTypeAsync("PhoneFormat", false);
void client_ListAllLookupValuesCompleted(object sender, ListAllLookupValuesByTypeCompletedEventArgs e)
{
// e.UserState will either be false or true
if ((bool)e.UserState)
cmbAddressFormat.ItemsSource = e.Result;
else
cmbPhonePrintFormat.ItemsSource = e.Result;
}
Related
There is a DataGrid with data in the Net 4.0 App. For the selected row, I get the value of one of the columns and pass it to the asynchronous method of the WCF service. Is it possible to pass this value as a result this method?
btn_Click(object sender, RoutedEventArgs e) {
DataRowView rv = (DataRowView)dgData.SelectedItem;
rv["TimeBeg"] = DateTime.Now.ToString("h:mm:ss");
string val=rv["Id"].ToString();
srAsync.ServClient clP = new srAsync.ServClient();
clP.MethodCompleted += cl_MethodComplete;
clP.MethodAsync(val);
}
After the call, the user can select another DataGrid Item, and call Async method for them, but in complete method I need to call another method with this value and update the rows DataGrid
private void cl_MethodComplete(object sender, srA.MethodCompletedEventArgs e) {
rv["TimeEnd"] = DateTime.Now.ToString("h:mm:ss");
sr.ServClient clP = new sr.ServClient();
clP.AnotherMethod(val);
...
What I would do is passing the row the user clicks on to the handler, using a lambda function:
btn_Click(object sender, RoutedEventArgs e) {
DataRowView rv = (DataRowView)dgData.SelectedItem;
rv["TimeBeg"] = DateTime.Now.ToString("h:mm:ss");
string val = rv["Id"].ToString();
srAsync.ServClient clP = new srAsync.ServClient();
clP.MethodCompleted += (currentSender, currentE) => cl_MethodComplete(currentSender, currentE, rv);
clP.MethodAsync(val);
}
Of course you will have to add another parameter to cl_MethodComplete, which will be able to work on the original row:
private void cl_MethodComplete(object sender, srA.MethodCompletedEventArgs e, DataRowView originalRow) {
originalRow["TimeEnd"] = DateTime.Now.ToString("h:mm:ss");
sr.ServClient clP = new sr.ServClient();
clP.AnotherMethod(val);
...
While I have found many instances of this question on SO, none of the solutions I have implemented have solved my problem; hopefully you can help me solve this riddle. Note: This is my first foray into the world of COM objects, so my ignorance is as deep as it is wide.
As a beginning, I am using Adrian Brown's Outlook Add-In code. I won't duplicate his CalendarMonitor class entirely; here are the relevant parts:
public class CalendarMonitor
{
private ItemsEvents_ItemAddEventHandler itemAddEventHandler;
public event EventHandler<EventArgs<AppointmentItem>> AppointmentAdded = delegate { };
public CalendarMonitor(Explorer explorer)
{
_calendarItems = new List<Items>();
HookupDefaultCalendarEvents(session);
}
private void HookupDefaultCalendarEvents(_NameSpace session)
{
var folder = session.GetDefaultFolder(OlDefaultFolders.olFolderCalendar);
if (folder == null) return;
try
{
HookupCalendarEvents(folder);
}
finally
{
Marshal.ReleaseComObject(folder);
folder = null;
}
}
private void HookupCalendarEvents(MAPIFolder calendarFolder)
{
var items = calendarFolder.Items;
_calendarItems.Add(items);
// Add listeners
itemAddEventHandler = new ItemsEvents_ItemAddEventHandler(CalendarItems_ItemAdd);
items.ItemAdd += itemAddEventHandler;
}
private void CalendarItems_ItemAdd(object obj)
{
var appointment = (obj as AppointmentItem);
if (appointment == null) return;
try
{
AppointmentAdded(this, new EventArgs<AppointmentItem>(appointment));
}
finally
{
Marshal.ReleaseComObject(appointment);
appointment = null;
}
}
Bits not relevant to adding appointments have been redacted.
I instantiate the CalendarMonitor class when I spool up the Add-in, and do the work in the AppointmentAdded event, including adding a UserProperty to the AppointmentItem:
private void ThisAddIn_Startup(object sender, EventArgs e)
{
_calendarMonitor = new CalendarMonitor(Application.ActiveExplorer());
_calendarMonitor.AppointmentAdded += monitor_AppointmentAdded;
}
private async void monitor_AppointmentAdded(object sender, EventArgs<AppointmentItem> e)
{
var item = e.Value;
Debug.Print("Outlook Appointment Added: {0}", item.GlobalAppointmentID);
try
{
var result = await GCalUtils.AddEventAsync(item);
//store a reference to the GCal Event for later.
AddUserProperty(item, Resources.GCalId, result.Id);
Debug.Print("GCal Appointment Added: {0}", result.Id);
}
catch (GoogleApiException ex)
{
PrintToDebug(ex);
}
finally
{
Marshal.ReleaseComObject(item);
item = null;
}
}
The error is thrown here, where I try to add a UserProperty to the AppointmentItem. I have followed the best example I could find:
private void AddUserProperty(AppointmentItem item, string propertyName, object value)
{
UserProperties userProperties = null;
UserProperty userProperty = null;
try
{
userProperties = item.UserProperties;
userProperty = userProperties.Add(propertyName, OlUserPropertyType.olText);
userProperty.Value = value;
item.Save();
}
catch (Exception ex)
{
Debug.Print("Error setting User Properties:");
PrintToDebug(ex);
}
finally
{
if (userProperty != null) Marshal.ReleaseComObject(userProperty);
if (userProperties != null) Marshal.ReleaseComObject(userProperties);
userProperty = null;
userProperties = null;
}
}
... but it chokes on when I try to add the UserProperty to the AppointmentItem. I get the ever-popular error: COM object that has been separated from its underlying RCW cannot be used. In all honesty, I have no idea what I'm doing; so I'm desperately seeking a Jedi Master to my Padawan.
The main problem here is using Marshal.ReleaseComObject for RCW's that are used in more than one place by the managed runtime.
In fact, this code provoked the problem. Let's see class CalendarMonitor:
private void CalendarItems_ItemAdd(object obj)
{
var appointment = (obj as AppointmentItem);
if (appointment == null) return;
try
{
AppointmentAdded(this, new EventArgs<AppointmentItem>(appointment));
}
finally
{
Marshal.ReleaseComObject(appointment);
After the event returns, it tells the managed runtime to release the COM object (from the point of view of the whole managed runtime, but no further).
appointment = null;
}
}
Then, an async event is attached, which will actually return before using the appointment, right at the await line:
private async void monitor_AppointmentAdded(object sender, EventArgs<AppointmentItem> e)
{
var item = e.Value;
Debug.Print("Outlook Appointment Added: {0}", item.GlobalAppointmentID);
try
{
var result = await GCalUtils.AddEventAsync(item);
This method actually returns here. C#'s async code generation breaks async methods at await points, generating continuation passing style (CPS) anonymous methods for each block of code that handles an awaited result.
//store a reference to the GCal Event for later.
AddUserProperty(item, Resources.GCalId, result.Id);
Debug.Print("GCal Appointment Added: {0}", result.Id);
}
catch (GoogleApiException ex)
{
PrintToDebug(ex);
}
finally
{
Marshal.ReleaseComObject(item);
Look, it's releasing the COM object again. No problem, but not optimal at all. This is an indicator of not knowing what is going on by using ReleaseComObject, it's better to avoid it unless proven necessary.
item = null;
}
}
In essence the use of ReleaseComObject should be subject to a thorough review of the following points:
Do I need to actually make sure the managed environment releases the object right now instead of at an indeterminate time?
Occasionally, some native objects need to be released to cause relevant side effects.
For instance, under a distributed transaction to make sure the object commits, but if you find the need to do that, then perhaps you're developing a serviced component and you're not enlisting objects in manual transactions properly.
Other times, you're iterating a huge set of objects, no matter how small each object is, and you may need to free them in order to not bring either your application or the remote application down. Sometimes, GC'ing more often, switching to 64-bit and/or adding RAM solves the problem in one way or the other.
Am I the sole owner of/pointer to the object from the managed environment's point of view?
For instance, did I create it, or was the object provided indirectly by another object I created?
Are there no further references to this object or its container in the managed environment?
Am I definitely not using the object after ReleaseComObject, in the code that follows it, or at any other time (e.g. by making sure not to store it in a field, or closure, even in the form of an iterator method or async method)?
This is to avoid the dreaded disconnected RCW exception.
I'm converting a Windows Phone 7 app to Windows Store, so I'm moving over to Xaml. I have a method that runs at a certain point to update the data on the screen. It either assigns or removes an event handler delegate to the CompositionTarget.Rendering event. The message I get is No overload for 'OnCompositionTargetRendering' matches delegate 'System.EventHandler' '
Here's what I have:
private void CheckCompleted()
{
Color completeColor;
if (this.DecryptedText.ToString().ToUpper() == this.ThisPuzzle.QuoteText.ToUpper())
{
// We're done!!! ...
CompositionTarget.Rendering -= this.OnCompositionTargetRendering;// new EventHandler(this.OnCompositionTargetRendering);
...
}
else
{
...
CompositionTarget.Rendering += this.OnCompositionTargetRendering;// new EventHandler(this.OnCompositionTargetRendering);
...
}
}
protected void OnCompositionTargetRendering(object sender, EventArgs args)
{
this.DisplayTime();
if (ThisPuzzle != null)
{
foreach (UIElement thisElement in Letters.Children)
{
...
}
}
}
If you check the documentation CompositionTarget.Rendering is of type EventHandler<object> in Windows Store apps and not of type EventHandler as in Silverlight.
This means you need to change the signature of your event handler accordingly to:
protected void OnCompositionTargetRendering(object sender, object args)
I am trying to call a function whose parameters are object sender and RoutedEventsArg e. I need those parameters since I have created a button on the main window related to this function and when I click the button it links to my function.
protected void StartRecord(object sender,RoutedEventsArg e)
{
// some stuff that creates a button and then does stuff
}
In another function, I need to call the above function stated above, but this second function has a parameter of AllFramesReadyArg e, not RoutedEventsArg e. So how do i call out the first function
void sensor_AllFramesReady(object sender, AllFramesReadyEventArgs e)
{
this.StartRecord(sender, e);
// does not work since parameter calls for RoutedEventArgs
}
Your StartRecord is not part of the Kinect Toolbox. You appear to have written it and given it those two arguments. It doesn't need them, nor do you necessarily need the function.
You also do not want to be calling StartRecord in AllFramesReady. The AllFramesReady callback is fired every time all the frames are ready for processing (hence the function name), which happens roughly 30 times a second. You only need to tell it to record once.
Per your other question, StartRecord is a callback to a button -- it shouldn't be called in code. It is called when the user hits the associated button.
Just looking at the Kinect Toolbox code and the callbacks, your code should look something like this:
KinectRecorder _recorder;
File _outStream;
bool _isRecording = false;
private void KinectSetup()
{
// set up the Kinect here
_recorder = new KinectRecorder(KinectRecordOptions.Skeleton, _outStream);
// some other stuff to setup
}
private void sensor_AllFramesReady(object sender, AllFramesReadyEventArgs e)
{
SkeletonFrame skeleton;
if (_isRecording && skeleton != null)
{
_recorder.Record(skeleton);
}
}
public void StartRecord(object sender, RoutedEventsArg e)
{
_isRecording = !_isRecording;
}
A wcf service accessing an SQL database:
private void GetImagesDataFromDB(int imageIndex, int **extraParam**)
{
ServiceReference1.DbServiceClient webService =
new ServiceReference1.DbServiceClient();
webService.GetSeriesImagesCompleted += new EventHandler<ServiceReference1.GetSeriesImagesCompletedEventArgs>(webService_GetSeriesImagesCompleted);
webService.GetSeriesImagesAsync(imageIndex);
}
the GetImageSeriesCompleted EventHandler is here:
void webService_GetSeriesImagesCompleted(object sender,
TheApp.ServiceReference1.GetSeriesImagesCompletedEventArgs e)
{
if (e.Result != null)
{
if (**extraParam** == 1)
{
lstImages = e.Result.ToList();
}
else
{
// do something else
}
}
}
The service itself is like this:
public List<Image> GetSeriesImages(int SeriesId)
{
DataClassDataContext db = new DataClassDataContext();
var images = from s in db.Images
where s.SeriesID == SeriesId
select s;
return images.ToList();
}
What is the best way to pass the extraParam to the service completed EventHandler? I need this to direct my service return to a proper UI control.
Thanks.
You've probably figured this out by now, but the webService.GetSeriesImagesAsync() call has a second overload, namely, webService.GetSeriesImagesAsync(int seriesId, object userState). That second parameter will get passed into the callback as e.UserState. A good pattern is actually to pass a lambda callback as the userstate, and execute that in the webService_GetSeriesImagesCompleted() method.