Expected a declaration

kaveh rahimi 61 Reputation points
2021-09-21T14:33:32.75+00:00

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

C++
C++
A high-level, general-purpose programming language, created as an extension of the C programming language, that has object-oriented, generic, and functional features in addition to facilities for low-level memory manipulation.
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2 answers

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  1. Viorel 111.8K Reputation points
    2021-09-21T16:07:38.117+00:00

    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";
}
    0 comments
  2. Minxin Yu 9,866 Reputation points Microsoft Vendor
    2021-09-22T02:21:35.863+00:00

    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

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