I am using register device notification for receiving USB Insertion/removal events so that I can populate the list present on my application. Here is my sample code for Register device Notification shown below:
DEV_BROADCAST_DEVICEINTERFACE NotificationFilter;
ZeroMemory( &NotificationFilter, sizeof(NotificationFilter) );
NotificationFilter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
NotificationFilter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
for(int i=0; i<sizeof(GUID_DEVINTERFACE_LIST)/sizeof(GUID); i++)
{
NotificationFilter.dbcc_classguid = GUID_DEVINTERFACE_LIST[i];
hDevNotify[i] = RegisterDeviceNotification(this->GetSafeHwnd(), &NotificationFilter, DEVICE_NOTIFY_WINDOW_HANDLE);
if(!hDevNotify[i])
{
WCHAR wszNotifyMsg[70];
wsprintf(wszNotifyMsg, L"%ls%d\n%ls%d", _T("Error in Registering Device Notification GUID Index:"),
i, _T("GetLastError:"), GetLastError());
MessageBox(wszNotifyMsg);
}
}
The code works fine when I use a simple usb drive, i get a notification and get all the logical disks present and display it. But when I connect a usb drive for multiple partitions, I receive notification when only one of the partition is mounted and i display it on the screen and after 1 sec other partition is mounted on the computer, but i receive no event.
Can u tell me what Iam doing wrong?
Sorry for my english.
Related
I try to run an example script from dronekit. the code is looks like this :
import gps
import socket
import time
from droneapi.lib import VehicleMode, Location
def followme():
"""
followme - A DroneAPI example
This is a somewhat more 'meaty' example on how to use the DroneAPI. It uses the
python gps package to read positions from the GPS attached to your laptop an
every two seconds it sends a new goto command to the vehicle.
To use this example:
* Run mavproxy.py with the correct options to connect to your vehicle
* module load api
* api start <path-to-follow_me.py>
When you want to stop follow-me, either change vehicle modes from your RC
transmitter or type "api stop".
"""
try:
# First get an instance of the API endpoint (the connect via web case will be similar)
api = local_connect()
# Now get our vehicle (we assume the user is trying to control the first vehicle attached to the GCS)
v = api.get_vehicles()[0]
# Don't let the user try to fly while the board is still booting
if v.mode.name == "INITIALISING":
print "Vehicle still booting, try again later"
return
cmds = v.commands
is_guided = False # Have we sent at least one destination point?
# Use the python gps package to access the laptop GPS
gpsd = gps.gps(mode=gps.WATCH_ENABLE)
while not api.exit:
# This is necessary to read the GPS state from the laptop
gpsd.next()
if is_guided and v.mode.name != "GUIDED":
print "User has changed flight modes - aborting follow-me"
break
# Once we have a valid location (see gpsd documentation) we can start moving our vehicle around
if (gpsd.valid & gps.LATLON_SET) != 0:
altitude = 30 # in meters
dest = Location(gpsd.fix.latitude, gpsd.fix.longitude, altitude, is_relative=True)
print "Going to: %s" % dest
# A better implementation would only send new waypoints if the position had changed significantly
cmds.goto(dest)
is_guided = True
v.flush()
# Send a new target every two seconds
# For a complete implementation of follow me you'd want adjust this delay
time.sleep(2)
except socket.error:
print "Error: gpsd service does not seem to be running, plug in USB GPS or run run-fake-gps.sh"
followme()
I try to run it in my Raspberry with Raspbian OS, but i got an error message like this :
Error : gpsd service does not seem to be running, plug in USB GPS or run run-fake-gps.sh
I get a feeling that my raspberry is needed a gps kind of device to be attached before i can run this script, but i dont really know.
Please kindly tell me whats wrong with it..
the full path of instruction i got from here :
http://python.dronekit.io/1.5.0/examples/follow_me.html
As the example says:
[This example] will use a USB GPS attached to your laptop to have the vehicle follow you as you walk around a field.
Without a GPS device, the code doesn't know where you are so it would not be possible to implement any sort of "following" behavior. Before running the example, you would need to:
Acquire some sort of GPS device (I use one of these, but there are lots of alternatives).
Configure gpsd on your laptop to interface with the GPS device.
I am trying to make a LabWindows/CVI program that talks with SPBT2632C2A Bluetooth chip. I am using a st eval spbt3atv3 dongle. I am trying to push a button and send a command to chip, but chip do not answer to me. I know my LabWindows program can receive messages from dongle, because every time I press reset button on dongle it shows me the boot up message. As I searched I need to add \n\r to end of my string, but it still didn't work. Chip does not send even error message.
CODE
int CVICALLBACK rasti (int panel, int control, int event,
void *callbackData, int eventData1, int eventData2)
{
switch (event)
{
case EVENT_COMMIT:
sprintf(discovery,"AT+AB discovery\n\r");
if(ComWrt (4,discovery, 18)!= 18){
SetCtrlVal (panelHandle, PANEL_TEXTBOX, "Nesekmingas duomenu siuntimas");
//Unsuccessful sending data
}
else {
SetCtrlVal (panelHandle, PANEL_TEXTBOX, discovery);
}
break;
}
return 0;
}
It's event called by button. It appends my discovery string to text box. So I think it's sending data correctly to serial port. But I think my string is wrong so I don't get the answer from chip.
Any ideas how to solve this to get responses from chip?
Make sure to call OpenComConfig with the correct parameters before invoking ComWrt. You can look for the correct port settings in the Hyperterminal (since you mentioned it communicates correctly with the device).
Refer to NI's documentation for more on this.
Also, trying different types of line termination characters might help (try using \r\n, \n or \r).
My task is to count the number of current monitors (screens) attached to the computer where my user-mode code below is running:
int nCnt = 0;
if(!EnumDisplayMonitors(NULL, NULL, countMonitorsProc, (LPARAM)&nCnt))
{
//Error
}
BOOL countMonitorsProc(HMONITOR hMonitor, HDC hdcMonitor, LPRECT lprcMonitor, LPARAM dwData)
{
int* pCnt = (int*)dwData;
(*pCnt)++;
return TRUE;
}
It works in most cases, but on some systems the EnumDisplayMonitors returns FALSE. Example of such system: my laptop where I attached an external monitor and shut the lid on it.
I'm curious, do I use the right approach for counting attached monitors?
If all you're wanting to know is how many monitors are connected, there should be no need to call EnumDisplayMonitors. The proper way to do this for physical (non-virtual) monitors is via GetSystemMetrics, with the index SM_CMONITORS.
SM_CMONITORS The number of display monitors on a desktop. For more
80 information, see the Remarks section in this topic.
From the Remarks section
GetSystemMetrics(SM_CMONITORS) counts only visible display monitors. This is different from EnumDisplayMonitors, which enumerates both visible display monitors and invisible pseudo-monitors that are associated with mirroring drivers. An invisible pseudo-monitor is associated with a pseudo-device used to mirror application drawing for remoting or other purposes.
The call then simply becomes
nCnt = GetSystemMetrics(SM_CMONITORS);
UPDATE: The plot thickens. I changed my channel name and it is suddenly working (which means it wasn't a problem with my push service, since I'm getting the same HTTP response from the Microsoft Push Notification server).
To me, however, this is not a solution. How will I be able to test this and KNOW my users are getting their push notifications if I'm getting the same response when it's not working as I do when it is?
[ORIGINAL POST]
I've been trying to get push notifications sent to my Windows Phone 7 device, but I'm having very big problems that I can't find any answers for. I'll start with the c# code.
I set up push notifications using the following C# code.
private HttpNotificationChannel channel;
private static string PUSH_CHANNEL = "MySpecialPushChannel";
private Uri PushUri = null;
private bool IsPushRegistered = false;
public void StartPushSubscription()
{
try
{
channel = HttpNotificationChannel.Find(PUSH_CHANNEL);
}
catch
{}
if (channel != null)
{
PushUri = channel.ChannelUri;
if (!channel.IsShellTileBound)
channel.BindToShellTile();
}
else
{
channel = new HttpNotificationChannel(PUSH_CHANNEL);
channel.ChannelUriUpdated += new EventHandler<NotificationChannelUriEventArgs>(channel_ChannelUriUpdated);
channel.HttpNotificationReceived += new EventHandler<HttpNotificationEventArgs>(channel_HttpNotificationReceived);
channel.ErrorOccurred += new EventHandler<NotificationChannelErrorEventArgs>(channel_ErrorOccurred);
try
{
channel.Open();
channel.BindToShellTile();
}
catch (Exception err)
{
channel = null;
IsPushRegistered = false;
// Code to try again
}
}
}
void channel_ChannelUriUpdated(object sender, NotificationChannelUriEventArgs e)
{
PushUri = e.ChannelUri;
IsPushRegistered = true;
}
I'm following the standard WP7 push structure:
Find the HttpNotificationChannel (or start a new one)
Register event handler to get the push notification uri back
Open the channel
Bind to the tile
Handle the channel Uri (which we send to our service to await the happy day when we send the push notification
OK... so far so good. No errors, I get my Uri, send it to my service just fine. I pin my app to the start screen and my service sends a push request to the Uri (sending just the count so that I get a little push count number in the upper right hand corner). I get back an HTTP 200 status with the following:
DeviceConnectionStatus => Connected
NotificationStatus => Received
SubscriptionStatus => Active
And then... nothing. No push status shows up on my app. I've now tried it on my device, in the emulator, on another device, and with multiple servers and the result is always the same. Everything looks like it is working except for the fact that it doesn't work.
To me, however, this is not a solution. How will I be able to test this and KNOW my users are getting their push notifications if I'm getting the same response when it's not working as I do when it is?
The answer is, you can't. It's a limitation of how WP7 handles notifications.
For structured notifications like Tile and Toast, if you get the Connected/Active/Received/200 response, then you can know that MPNS accepted your notification request. However, this does not mean that you have sent a valid XML payload.
The component that handles parsing XML is the Push Client, the process running on the phone that accepts push notifications and deals them out to appropriate applications, displays the toast, etc.
If you have sent invalid XML, there is absolutely no indication that you've done so. At most, if you try to send the notification again to that same push channel URI, you'll get a 404 in response. Apparently getting an invalid XML payload for a specific application makes that application's push channel close, requiring you to go through the whole procedure again.
I've discovered this while debugging with our server team, and through trying to get the phone to display an alternate live tile. The only advice I can offer you is to quadruple-check your XML.
You will get errors in your error event handler for your push notification channel for Toast notifications that have invalid XML, since you are able to send/receive toast notifications while the application is active.
If anyone from Microsoft is reading this, PLEASE provide more thorough documentation on possible error states in the push notification system. We also need an event handler for Tile notifications, or at least allow us to receive tile notifications while the app is in the foreground and fire the notification channel error event so that we can be aware that our XML payload is invalid.
Especially if your web service isn't built with WCF, .NET, Azure, and whatever, working with Push Notifications on WP7 is like wandering blind.
Documentation for an exception message reading "InvalidOperationException(Failed to open channel)" should not read: "This exception is raised when the notification channel failed to open. Try opening the notification channel again." (reference)
are you getting the URL from each device? you need to get a URL from the push notification sevice for each device everytime your device connects,
when it does you need to find a way of retrieving the url from each client,
once you do that and your still not receiving push notifications then I would write to microsoft to see if they can see anything to do with the push notifications
We are working on a C language application which is simple RTSP/RTP client to record video from Axis a number of Cameras. We launch a pthread for each of the camera which establishes the RTP session and begin to record the packets captured using the recvfrom() call.
A single camera single pthread records fine for well over a day without issues.
But testing with more cameras available,about 25(so 25 pthreads), the recording to file goes fine for like 15 to 20 mins and then the recording just stops. The application still keeps running. Its been over a month and a half we have been trying with varied implementations but nothing seems to help. Please provide suggestions.
We are using CentOS 5 platform
Define "record" Does that mean write data to a file? How do you control access to the file?
You can't have several threads all trying to write at the exact same time. So the comment by Alon seems to be pertinent. Your write access control machanism has problems.
void *IPThread(void *ptr)
{
//Establish RTSP session
//Bind to RTP ports(video)
//Increase Socket buffer size to 625KB
record_fd=open(record_name, O_CREAT|O_RDWR|O_TRUNC, 0777);
while(1)
{
if(poll(RTP/RTCP ports)) //a timeout value of 1
{
if(RTCP event)
RTCPhandler();
if(RTP event)
{
recvfrom(); //the normal socket api recvfrom
WritePacketToFile(record_fd)
{
//Create new record_fd after 100MB
}
}
}
}
}
even if it is alright to stick to the single threaded implementation why is the multithreaded approach behaving such a way(not recording after ~15 mins)..?