LPOVERLAPPED_COMPLETION_ROUTINE 与函数不兼容

Question

我想使用 WriteFileEx 从 winapi 将数据异步写入文件，但回调有问题。

我收到跟随错误： "void (*) (DWORD dwErrorCode, DWORD dwNumberOfBytesTransfered, LPOVERLAPPED lpOverlapped)" 类型的参数与 "LPOVERLAPPED_COMPLETION_ROUTINE"

类型的参数不兼容

我做错了什么？

代码如下：

// Callback
void onWriteComplete(
        DWORD dwErrorCode,
        DWORD dwNumberOfBytesTransfered,
        LPOVERLAPPED lpOverlapped) {
    return;
}

BOOL writeToOutputFile(String ^outFileName, List<String ^> ^fileNames) {
    HANDLE hFile;
    char DataBuffer[] = "This is some test data to write to the file.";
    DWORD dwBytesToWrite = (DWORD) strlen(DataBuffer);
    DWORD dwBytesWritten = 0;
    BOOL bErrorFlag = FALSE;

    pin_ptr<const wchar_t> wFileName = PtrToStringChars(outFileName);

    hFile = CreateFile(
        wFileName,              // name of the write
        GENERIC_WRITE,          // open for writing
        0,                      // do not share
        NULL,                   // default security
        CREATE_NEW,             // create new file only
        FILE_FLAG_OVERLAPPED, 
        NULL);                  // no attr. template

    if (hFile == INVALID_HANDLE_VALUE) {
        return FALSE;
    }

    OVERLAPPED oOverlap;
    bErrorFlag = WriteFileEx(
        hFile,           // open file handle
        DataBuffer,      // start of data to write
        dwBytesToWrite,  // number of bytes to write
        &oOverlap,      // overlapped structure
        onWriteComplete),

    CloseHandle(hFile);
}

Answer 1

您应该先仔细阅读 documentation。这部分特别重要：

The OVERLAPPED data structure must remain valid for the duration of the write operation. It should not be a variable that can go out of scope while the write operation is pending completion.

您不符合该要求，您需要紧急解决该问题。

至于编译错误，很简单。您的回调不符合要求。再次查阅 documentation，其签名为：

VOID CALLBACK FileIOCompletionRoutine(
  _In_     DWORD dwErrorCode,
  _In_     DWORD dwNumberOfBytesTransfered,
  _Inout_  LPOVERLAPPED lpOverlapped
);

您省略了指定调用约定的 CALLBACK。

LPOVERLAPPED_COMPLETION_ROUTINE 与函数不兼容

LPOVERLAPPED_COMPLETION_ROUTINE is incompatible with function

winapi

c++-cli

writefile