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<< Click to Display Table of Contents >> Navigation: NmxDLL Reference Guide > HowTo > Sampling > Get sampling status > Sampling notifications |
Notifications are very useful to get informed about any changes of the sampling. For a complete list of all available notifications, please consult the chapter "Notifications".
To receive the notifications, these must be registered. Depending on the selected notification type (messages or callbacks), a message handler or a callback function must be implemented.
In the following sample code, message based notifications are used.
C / C++
// Define Message. In VisualStudio, WM_USER is defined in WinUser.h as:
// #define WM_USER 0x0400
#define WM_MESSAGE_SAMPLING_NEWDATA (WM_USER + NMXNOTIFY_SAMPLING_NEW_DATA) // Message for "new sampling data" received
#define WM_MESSAGE_SAMPLING_ALLRECEIVED (WM_USER + NMXNOTIFY_SAMPLING_ALL_DATA_RECEIVED) // Message for "all sampling data has been received"
#define WM_MESSAGE_SAMPLING_FINISHED (WM_USER + NMXNOTIFY_SAMPLING_FINISHED) // Message for "sampling is finished"
#define WM_MESSAGE_SAMPLING_ERROR (WM_USER + NMXNOTIFY_SAMPLING_ERROR) // Message for "sampling error"
#define WM_MESSAGE_SAMPLING_BUFFER_OVERFLOW (WM_USER + NMXNOTIFY_SAMPLING_BUFFER_OVERFLOW) // Message for "sampling buffer overflow in DLL"
#define WM_MESSAGE_SAMPLING_TIMEOUT (WM_USER + NMXNOTIFY_SAMPLING_TIMEOUT) // Message for "sampling: timeout receiving data"
// ###-> Register notifications, e.g. directly after connecting.
if (NMX_RegisterMessage_1(pHandleNmx, NMXNOTIFY_SAMPLING_NEW_DATA, static_cast<HWND>(Handle.ToPointer()), WM_MESSAGE_SAMPLING_NEWDATA, 0, 0) != NST_SUCCESS) {
// Handle error
}
if (NMX_RegisterMessage_1(pHandleNmx, NMXNOTIFY_SAMPLING_ALL_DATA_RECEIVED, static_cast<HWND>(Handle.ToPointer()), WM_MESSAGE_SAMPLING_ALLRECEIVED, 0, 0) != NST_SUCCESS) {
// Handle error
}
if (NMX_RegisterMessage_1(pHandleNmx, NMXNOTIFY_SAMPLING_FINISHED, static_cast<HWND>(Handle.ToPointer()), WM_MESSAGE_SAMPLING_FINISHED, 0, 0) != NST_SUCCESS) {
// Handle error
}
if (NMX_RegisterMessage_1(pHandleNmx, NMXNOTIFY_SAMPLING_ERROR, static_cast<HWND>(Handle.ToPointer()), WM_MESSAGE_SAMPLING_ERROR, 0, 0) != NST_SUCCESS) {
// Handle error
}
if (NMX_RegisterMessage_1(pHandleNmx, NMXNOTIFY_SAMPLING_BUFFER_OVERFLOW, static_cast<HWND>(Handle.ToPointer()), WM_MESSAGE_SAMPLING_BUFFER_OVERFLOW, 0, 0) != NST_SUCCESS) {
// Handle error
}
if (NMX_RegisterMessage_1(pHandleNmx, NMXNOTIFY_SAMPLING_TIMEOUT, static_cast<HWND>(Handle.ToPointer()), WM_MESSAGE_SAMPLING_TIMEOUT, 0, 0) != NST_SUCCESS) {
// Handle error
}
// ###-> Implement message handler
// Please note: Keep the code in the message handler as short as possible.
// Do not update the GUI from within the message handlers.
protected: virtual void WndProc(Message% m) override
{
/* Listen for operating system messages. */
switch (m.Msg)
{
case WM_MESSAGE_SAMPLING_NEWDATA:
break;
case WM_MESSAGE_SAMPLING_ALLRECEIVED:
break;
case WM_MESSAGE_SAMPLING_FINISHED:
break;
case WM_MESSAGE_SAMPLING_ERROR:
break;
case WM_MESSAGE_SAMPLING_BUFFER_OVERFLOW:
break;
case WM_MESSAGE_SAMPLING_TIMEOUT:
break;
default:
/* Pass all standard messages to the GUI form. */
Form::WndProc(m);
break;
}
}
Delphi
// Define Message for "new static data available"
const WM_MESSAGE_NMX_SAMPLING_NEW_DATA = WM_USER + NMXNOTIFY_SAMPLING_NEW_DATA;
WM_MESSAGE_NMX_SAMPLING_FINISHED = WM_USER + NMXNOTIFY_SAMPLING_FINISHED;
WM_MESSAGE_NMX_SAMPLING_ALL_DATA_RECEIVED = WM_USER + NMXNOTIFY_SAMPLING_ALL_DATA_RECEIVED;
WM_MESSAGE_NMX_SAMPLING_ERROR = WM_USER + NMXNOTIFY_SAMPLING_ERROR;
WM_MESSAGE_NMX_SAMPLING_BUFFER_OVERFLOW = WM_USER + NMXNOTIFY_SAMPLING_BUFFER_OVERFLOW;
WM_MESSAGE_NMX_SAMPLING_TIMEOUT = WM_USER + NMXNOTIFY_SAMPLING_TIMEOUT;
// Declaration of message handler. Integrate it into the class declarations.
procedure OnMessageSamplingNewData(var Msg: TMessage); message WM_MESSAGE_NMX_SAMPLING_NEW_DATA;
procedure OnMessageSamplingFinished(var Msg: TMessage); message WM_MESSAGE_NMX_SAMPLING_FINISHED;
procedure OnMessageSamplingAllDataReceived(var Msg: TMessage); message WM_MESSAGE_NMX_SAMPLING_ALL_DATA_RECEIVED;
procedure OnMessageSamplingError(var Msg: TMessage); message WM_MESSAGE_NMX_SAMPLING_ERROR;
procedure OnMessageSamplingBufferOverflow(var Msg: TMessage); message WM_MESSAGE_NMX_SAMPLING_BUFFER_OVERFLOW;
procedure OnMessageSamplingTimeout(var Msg: TMessage); message WM_MESSAGE_NMX_SAMPLING_TIMEOUT;
// ###-> Register notification, e.g. directly after connecting.
if NMX_RegisterMessage_1(pNmxHandle, NMXNOTIFY_SAMPLING_NEW_DATA, MainForm.Handle, WM_MESSAGE_NMX_SAMPLING_NEW_DATA, 0, 0) <> NST_SUCCESS then begin
// Registering notification failed. Do some error handling
end;
if NMX_RegisterMessage_1(pNmxHandle, NMXNOTIFY_SAMPLING_FINISHED, MainForm.Handle, WM_MESSAGE_NMX_SAMPLING_FINISHED, 0, 0) <> NST_SUCCESS then begin
// Registering notification failed. Do some error handling
end;
if NMX_RegisterMessage_1(pNmxHandle, NMXNOTIFY_SAMPLING_ALL_DATA_RECEIVED, MainForm.Handle, WM_MESSAGE_NMX_SAMPLING_ALL_DATA_RECEIVED, 0, 0) <> NST_SUCCESS then begin
// Registering notification failed. Do some error handling
end;
if NMX_RegisterMessage_1(pNmxHandle, NMXNOTIFY_SAMPLING_ERROR, MainForm.Handle, WM_MESSAGE_NMX_SAMPLING_ERROR, 0, 0) <> NST_SUCCESS then begin
// Registering notification failed. Do some error handling
end;
if NMX_RegisterMessage_1(pNmxHandle, NMXNOTIFY_SAMPLING_BUFFER_OVERFLOW, MainForm.Handle, WM_MESSAGE_NMX_SAMPLING_BUFFER_OVERFLOW, 0, 0) <> NST_SUCCESS then begin
// Registering notification failed. Do some error handling
end;
if NMX_RegisterMessage_1(pNmxHandle, NMXNOTIFY_SAMPLING_TIMEOUT, MainForm.Handle, WM_MESSAGE_NMX_SAMPLING_TIMEOUT, 0, 0) <> NST_SUCCESS then begin
// Registering notification failed. Do some error handling
end;
// ###-> Implement message handlers
// Please note: Keep the code in the message handlers as short as possible.
// Do not update the GUI from within the message handlers.
C# / .Net
// Define Messages. In VisualStudio, WM_USER is 0x0400
const int WM_USER = 0x400;
const int WM_MESSAGE_SAMPLING_NEW_DATA = WM_USER + 0x20;
const int WM_MESSAGE_SAMPLING_FINISHED = WM_USER + 0x21;
public const int WM_MESSAGE_SAMPLING_ALL_DATA_RECEIVED = WM_USER + 0x22;
public const int WM_MESSAGE_SAMPLING_ERROR = WM_USER + 0x28;
public const int WM_MESSAGE_SAMPLING_BUFFER_OVERFLOW = WM_USER + 0x29;
public const int WM_MESSAGE_SAMPLING_TIMEOUT = WM_USER + 0x2A;
// ###-> Register notifications, e.g. directly after connecting.
NMX_MSTATUS tStatus = NMX_MSTATUS.UNKNOWN;
tStatus = cNmx.RegisterMessage_1(pDevice, NMX_NOTIFICATION.SAMPLING_NEW_DATA, Handle, WM_MESSAGE_SAMPLING_NEW_DATA, 0, 0);
if (tStatus != NMX_MSTATUS.SUCCESS) { /* Do some error handling */ }
tStatus = cNmx.RegisterMessage_1(pDevice, NMX_NOTIFICATION.SAMPLING_ALL_DATA_RECEIVED, Handle, WM_MESSAGE_SAMPLING_ALL_DATA_RECEIVED, 0, 0);
if (tStatus != NMX_MSTATUS.SUCCESS) { /* Do some error handling */ }
tStatus = cNmx.RegisterMessage_1(pDevice, NMX_NOTIFICATION.SAMPLING_FINISHED, Handle, WM_MESSAGE_SAMPLING_FINISHED, 0, 0);
if (tStatus != NMX_MSTATUS.SUCCESS) { /* Do some error handling */ }
tStatus = cNmx.RegisterMessage_1(pDevice, NMX_NOTIFICATION.SAMPLING_ERROR, Handle, WM_MESSAGE_SAMPLING_ERROR, 0, 0);
if (tStatus != NMX_MSTATUS.SUCCESS) { /* Do some error handling */ }
tStatus = cNmx.RegisterMessage_1(pDevice, NMX_NOTIFICATION.SAMPLING_BUFFER_OVERFLOW, Handle, WM_MESSAGE_SAMPLING_BUFFER_OVERFLOW, 0, 0);
if (tStatus != NMX_MSTATUS.SUCCESS) { /* Do some error handling */ }
tStatus = cNmx.RegisterMessage_1(pDevice, NMX_NOTIFICATION.SAMPLING_TIMEOUT, Handle, WM_MESSAGE_SAMPLING_TIMEOUT, 0, 0);
if (tStatus != NMX_MSTATUS.SUCCESS) { /* Do some error handling */ }
// ###-> Implement message handler
// Please note: Keep the code in the message handler as short as possible.
// Do not update the GUI from within the message handlers.
protected override void WndProc(ref Message m)
{
// Listen for operating system messages.
switch (m.Msg)
{
case WM_MESSAGE_SAMPLING_NEW_DATA:
break;
case WM_MESSAGE_SAMPLING_FINISHED:
break;
case WM_MESSAGE_SAMPLING_ALL_DATA_RECEIVED:
break;
case WM_MESSAGE_SAMPLING_ERROR:
break;
case WM_MESSAGE_SAMPLING_BUFFER_OVERFLOW:
break;
case WM_MESSAGE_SAMPLING_TIMEOUT:
break;
default:
/* Pass all standard messages to the GUI form. */
base.WndProc(ref m);
break;
}
}