Question

我想在静态wlan函数注册notificationCallBack连接时发出信号。

代码：

WirelessConnect.h

static void WINAPI notificationCallBack(PWLAN_NOTIFICATION_DATA wlanData, PVOID context);

WirelessConnect.cpp

DWORD dwResult = 0;
dwResult = WlanRegisterNotification(hClient, WLAN_NOTIFICATION_SOURCE_ALL, TRUE, notificationCallBack, NULL, NULL, &dwPrevNotif);

void WINAPI WirelessConnect::notificationCallBack(PWLAN_NOTIFICATION_DATA wlanData, PVOID context)
{
    context = NULL;
    switch (wlanData->NotificationCode) {
        case wlan_notification_acm_connection_complete:
            emit apConnectionComplete();
            qDebug() << "Connected!";
        break;

        case wlan_notification_acm_connection_attempt_fail:
            emit apConnectionFailed();
            qDebug() << "Failed!";
        break;

        default:
            break;
    }
}

测试.cpp：

WirelessConnect *wirelessAPConnect = new WirelessConnect();
connect(wirelessAPConnect, &WirelessConnect::apConnectionComplete, setAPConnection);
connect(wirelessAPConnect, &WirelessConnect::apConnectionFailed, setAPConnectionFailed);

问题是error: C2355: 'this': can only be referenced inside non-static member functions or non-static data member initializers。

那么如何从static函数发出信号，例如在QMessageBox类中显示关于wlan连接的Test？

上述链接中的解决方案无效：

1方法：notificationCallBack(PWLAN_NOTIFICATION_DATA wlanData, PVOID context)函数只需要2个参数PWLAN_NOTIFICATION_DATA wlanData和PVOID context，而不是对类的引用作为参数

2方法：导致错误：连接中的C3867: 'WirelessConnect::apConnectionComplete': non-standard syntax; use '&' to create a pointer to member： connect(wirelessAPConnect, WirelessConnect::apConnectionComplete, this, &Test::setAPConnection);

我已使用2方法修复了编译错误，但它没有发出任何内容。

代码：

WirelessConnect.cpp

static WirelessConnect wirelessConnectObj;

void WINAPI WirelessConnect::notificationCallBack(PWLAN_NOTIFICATION_DATA wlanData, PVOID context)
{
    context = NULL;
    switch (wlanData->NotificationCode) {
        case wlan_notification_acm_connection_complete:
            wirelessConnectObj.apConnectionComplete();
            qDebug() << "Connected!";
        break;

        case wlan_notification_acm_connection_attempt_fail:
            wirelessConnectObj.apConnectionFailed();
            qDebug() << "Failed!";
        break;

        default:
            break;
    }
}

dwResult = WlanRegisterNotification(hClient, WLAN_NOTIFICATION_SOURCE_ALL, TRUE, notificationCallBack, NULL, NULL, &dwPrevNotif);

Test.cpp的

WirelessConnect *wirelessAPConnect = new WirelessConnect();
connect(wirelessAPConnect, &WirelessConnect::apConnectionComplete, this, &Test::setAPConnection);
connect(wirelessAPConnect, &WirelessConnect::apConnectionFailed, this, &Test::setAPConnectionFailed);

没有编译错误，setAPConnection没有执行。

我认为static WirelessConnect wirelessConnectObj;为NULL并且它什么都不执行。当我使用静态WirelessConnect * wirelessConnectObj时;作为app连接到Access Point后的指针，然后应用程序崩溃。

初始化static WirelessConnect *wirelessConnectObj = new WirelessConnect();时，应用程序可以正常工作，但没有信号/插槽执行。

编辑：

WirelessConnect类还管理其他非静态wlan函数，这些函数连接到信号和插槽。所以我无法删除wirelessAPConnect对象并仅使用静态对象。我已在static WirelessConnect wirelessConnectObj;初个化Test并将其连接起来：

connect(&wirelessConnectObj, &WirelessConnect::apConnectionComplete, this, &Test::setAPConnection);
connect(&wirelessConnectObj, &WirelessConnect::apConnectionFailed, this, &Test::setAPConnectionFailed);

输出相同 - 没有。我想，这是因为我创建了2个不同的WirelessConnect类静态实例。我只需要一个WirelessConnect的静态实例，它应该是全局的，以发送信号并在Test中连接它们。

Answer 1

我已经解决了这个问题：

我将this设置为函数：

WlanRegisterNotification(hClient, WLAN_NOTIFICATION_SOURCE_ALL, TRUE, notificationCallBack, this, NULL, &dwPrevNotif);

void WINAPI WirelessConnect::notificationCallBack(PWLAN_NOTIFICATION_DATA wlanData, PVOID context)
{
    WirelessConnect *pThis = (WirelessConnect*) context;
    switch (wlanData->NotificationCode) {
        case wlan_notification_acm_connection_complete:
            pThis->apConnectionComplete();
            qDebug() << "Connected!";
        break;

        case wlan_notification_acm_connection_attempt_fail:
            pThis->apConnectionFailed();
            qDebug() << "Failed!";
        break;

        default:
            break;
    }
}

然后将其连接为非静态实例：

connect(wirelessAPConnect, &WirelessConnect::apConnectionComplete, this, &Test::setAPConnection); 
connect(wirelessAPConnect, &WirelessConnect::apConnectionFailed, this, &Test::setAPConnectionFailed);

所以我不再需要静态全局实例了，现在就可以了。

<强>编辑：

在某些诊断（连接/断开与接入点之间）后，解决方案会导致应用程序崩溃。

从静态功能问题发出信号

1 个答案: