类中的创建线程错误:类型'DWORD (windows_thread::)(void*)'的参数与"DWORD (*)(void*)"不匹配?

CreateThread inside a class error: argument of type 'DWORD (windows_thread::)(void*)' does not match 'DWORD (*)(void*)'?

本文关键字:void DWORD 参数 不匹配 创建 线程 类型 错误 windows thread      更新时间:2023-10-16

我试图在类内创建一个线程,但遇到了错误。我只是想知道是否有办法解决这个问题,或者我必须仅在int main()中使用线程?

C:windows_thread_2windows_thread_2.cpp||In member function 'void windows_thread::thread()':|
C:windows_thread_2windows_thread_2.cpp|24|error: argument of type 'DWORD (windows_thread::)(void*)' does not match 'DWORD (*)(void*)'|
C:windows_thread_2windows_thread_2.cpp||In member function 'DWORD windows_thread::Thread_no_1(void*)':|
C:windows_thread_2windows_thread_2.cpp|70|warning: deprecated conversion from string constant to 'char*'|
||=== Build finished: 1 errors, 1 warnings ===|

这是代码。

#include <windows.h>
//#include <strsafe.h>
#include <stdio.h>
#define BUF_SIZE 255
class windows_thread
{
//-------------------------------------------------------------------
// A function to Display the message indicating in which tread we are
//-------------------------------------------------------------------
    public:
        windows_thread(){}
        ~windows_thread(){}
        void thread()
        {
            int Data_Of_Thread_1 = 1;            // Data of Thread 1
            HANDLE Handle_Of_Thread_1 = 0;       // variable to hold handle of Thread 1
            HANDLE Array_Of_Thread_Handles[1];   // Aray to store thread handles
    // Create thread 1.
            Handle_Of_Thread_1 = CreateThread( NULL, 0, Thread_no_1, &Data_Of_Thread_1, 0, NULL);
            if ( Handle_Of_Thread_1 == NULL)  ExitProcess(Data_Of_Thread_1);
    // Store Thread handles in Array of Thread Handles as per the requirement of WaitForMultipleObjects()
            Array_Of_Thread_Handles[0] = Handle_Of_Thread_1;

    // Wait until all threads have terminated.
            WaitForMultipleObjects( 1, Array_Of_Thread_Handles, TRUE, INFINITE);
            printf("Since All threads executed lets close their handles n");
    // Close all thread handles upon completion.
            CloseHandle(Handle_Of_Thread_1);
        }
        void DisplayMessage (HANDLE hScreen, char *ThreadName, int Data, int Count)
        {
            TCHAR msgBuf[BUF_SIZE];
            size_t cchStringSize;
            DWORD dwChars;
    // Print message using thread-safe functions.
    //StringCchPrintf(msgBuf, BUF_SIZE, TEXT("Executing iteration %02d of %s having data = %02d n"), Count, ThreadName, Data);
    //StringCchLength(msgBuf, BUF_SIZE, &cchStringSize);
            WriteConsole(hScreen, msgBuf, cchStringSize, &dwChars, NULL);
            Sleep(1000);
        }
//-------------------------------------------
// A function that represents Thread number 1
//-------------------------------------------
        DWORD WINAPI Thread_no_1( LPVOID lpParam )
        {
            int     Data = 0;
            int     count = 0;
            HANDLE  hStdout = NULL;
    // Get Handle To screen. Else how will we print?
            if( (hStdout = GetStdHandle(STD_OUTPUT_HANDLE)) == INVALID_HANDLE_VALUE )
                return 1;
    // Cast the parameter to the correct data type passed by callee i.e main() in our case.
            Data = *((int*)lpParam);
            for (count = 0; count <= 4; count++ )
            {
                DisplayMessage (hStdout, "Thread_no_1", Data, count);
            }
            return 0;
        }
};
int main()
{
    windows_thread threading;
    threading.thread();
    return 0;
}

我根据答案编辑了代码,如果您可以解决此错误,请对其进行编辑。 line 78 error: no matching function for call to 'windows_thread::Thread_no_1()'|

#include <windows.h>
//#include <strsafe.h>
#include <stdio.h>
#define BUF_SIZE 255
class windows_thread
{
//-------------------------------------------------------------------
// A function to Display the message indicating in which tread we are
//-------------------------------------------------------------------
    public:
        windows_thread(){}
        ~windows_thread(){}
        void thread()
        {
            int Data_Of_Thread_1 = 1;            // Data of Thread 1
            HANDLE Handle_Of_Thread_1 = 0;       // variable to hold handle of Thread 1
            HANDLE Array_Of_Thread_Handles[1];   // Aray to store thread handles
    // Create thread 1.
            Handle_Of_Thread_1 = CreateThread( NULL, 0,  Wrap_Thread_no_1, &Data_Of_Thread_1, 0, NULL);
            if ( Handle_Of_Thread_1 == NULL)  ExitProcess(Data_Of_Thread_1);
    // Store Thread handles in Array of Thread Handles as per the requirement of WaitForMultipleObjects()
            Array_Of_Thread_Handles[0] = Handle_Of_Thread_1;

    // Wait until all threads have terminated.
            WaitForMultipleObjects( 1, Array_Of_Thread_Handles, TRUE, INFINITE);
            printf("Since All threads executed lets close their handles n");
    // Close all thread handles upon completion.
            CloseHandle(Handle_Of_Thread_1);
        }
        void DisplayMessage (HANDLE hScreen, char *ThreadName, int Data, int Count)
        {
            TCHAR msgBuf[BUF_SIZE];
            size_t cchStringSize;
            DWORD dwChars;
    // Print message using thread-safe functions.
    //StringCchPrintf(msgBuf, BUF_SIZE, TEXT("Executing iteration %02d of %s having data = %02d n"), Count, ThreadName, Data);
    //StringCchLength(msgBuf, BUF_SIZE, &cchStringSize);
            WriteConsole(hScreen, msgBuf, cchStringSize, &dwChars, NULL);
            Sleep(1000);
        }
//-------------------------------------------
// A function that represents Thread number 1
//-------------------------------------------
        DWORD WINAPI Thread_no_1( LPVOID lpParam )
        {
            int     Data = 0;
            int     count = 0;
            HANDLE  hStdout = NULL;
    // Get Handle To screen. Else how will we print?
            if( (hStdout = GetStdHandle(STD_OUTPUT_HANDLE)) == INVALID_HANDLE_VALUE )
                return 1;
    // Cast the parameter to the correct data type passed by callee i.e main() in our case.
            Data = *((int*)lpParam);
            for (count = 0; count <= 1; count++ )
            {
                //DisplayMessage (hStdout, "Thread_no_1", Data, count);
            }
            return 0;
        }
        static DWORD WINAPI Wrap_Thread_no_1( LPVOID lpParam )
        {
            windows_thread *self = reinterpret_cast<windows_thread*>(lpParam);
            self->Thread_no_1();
        }
};
int main()
{
    windows_thread threading;
    threading.thread();
    return 0;
}
线程

必须是"纯函数",而不是对类的非静态成员函数的调用 - 这些需要为"this-pointer"提供额外的"隐藏"参数。

由于到目前为止您的代码没有使用任何成员变量[据我所知],因此简单的解决方案是使函数static

如果要使用类的成员变量或成员函数,则需要有一个静态函数并将对象(this(作为参数的一部分传递给线程,然后使用reinterpret_cast<windows_thread*>(arg);将其转换回来。

大致如下:

... 
    Handle_Of_Thread_1 = CreateThread( NULL, 0, Wrap_Thread_no_1, this, 0, NULL);
... 
    static DWORD WINAPI Wrap_Thread_no_1( LPVOID lpParam )
    {
          windows_thread *self = reinterpret_cast<windows_thread*>(lpParam);
          self->Thread_no_1();
    }

我已经删除了你原来的论点。假设线程每个对象只运行一个线程,则可以将其设置为成员变量。如果您需要具有单个参数的多个线程,则需要将传入的参数设为structclass,并reinterpret_cast,并将this指针存储为该structclass的一部分[然后可以windows_thread*,因此不需要强制转换]。

您正在尝试将指向成员的指针传递给线程,这与此处的原始指针不同。 它需要一个对象附加到它。

Handle_Of_Thread_1 = CreateThread( NULL, 0, Thread_no_1, &Data_Of_Thread_1, 0, NULL);

通过更改以下内容使函数static

    DWORD WINAPI Thread_no_1( LPVOID lpParam )

对此:

    static DWORD WINAPI Thread_no_1( LPVOID lpParam )

。它(正确(指出此函数不需要this.