Expected a declaration

Question

Hi , I debug the code below:

include <windows.h>

include <iostream>

typedef     VOID(CALLBACK   * mPCH341_NOTIFY_ROUTINE) (  // É豸ʼþ֪ͨ»Øµ÷³ÌÐò
    ULONG           iEventStatus);  // É豸ʼþºÍµ±Ç°×´Ì¬(ÔÚÏÂÐж¨Òå): 0=É豸°Î³öʼþ, 3=É豸²åÈëʼþ

define CH341_DEVICE_ARRIVAL 3 // É豸²åÈëʼþ,ÒѾ­²åÈë

define CH341_DEVICE_REMOVE_PEND 1 // É豸½«Òª°Î³ö

define CH341_DEVICE_REMOVE 0 // É豸°Î³öʼþ,ÒѾ­°Î³ö

BOOL    WINAPI  CH341SetDeviceNotify(
    ULONG                   iIndex,
    PCHAR                   iDeviceID,
    mPCH341_NOTIFY_ROUTINE  iNotifyRoutine);
if (CH341SetDeviceNotify(
    ULONG                   iIndex,
    PCHAR                   iDeviceID,
    mPCH341_NOTIFY_ROUTINE  iNotifyRoutine) == 1) {
    cout << "usb port connected";
}

And receive the error E0169 which concerns the line of 'if' statement.How can I fix it?
Please help
Thanks

Answer 1

Hi, kavehrahimi-5744

The error E0169:

   if (CH341SetDeviceNotify(  
         ULONG                    iIndex,  
         PCHAR                    iDeviceID,  
         mPCH341_NOTIFY_ROUTINE    iNotifyRoutine) == 1) {  
         cout << "usb port connected";  
     }  

if(CH341SetDeviceNotify()) should be used in main() or other function.
The function needs to be defined and requires three arguments as Viorel-1 said.
By the way, cout needs to be changed to std::cout.

Best regards,

Minxin Yu

---

If the response is helpful, please click "Accept Answer" and upvote it.

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Answer 2

CH341SetDeviceNotify is a function that requires three arguments. For example:

void CALLBACK MyNotifyRoutine( ULONG iEventStatus )
{
    //
}

. . . .

ULONG iIndex = 0; // probably it is zero
PCHAR iDeviceID = ???; // use the device's ID
mPCH341_NOTIFY_ROUTINE iNotifyRoutine = &MyNotifyRoutine;

if (CH341SetDeviceNotify( iIndex, iDeviceID, iNotifyRoutine)) 
{
     cout << "done";
}