请教个DirectInput的问题

hdm2968

我做DInput时遇到困难了，初始化没出错，但不知漏了些什么了，这些是全部的DInput代码：
LPDIRECTINPUT8            pInput          = NULL;
LPDIRECTINPUTDEVICE8      pInputDev       = NULL;
...............
void InitInput()//初始化
{
            HRESULT hr;

        hr=DirectInput8Create(GetModuleHandle(NULL),
                DIRECTINPUT_VERSION,
                IID_IDirectInput8,
                (void**)&pInput,
                NULL);
        hr=pInput->CreateDevice(GUID_SysMouse, &pInputDev, NULL);
        hr=pInputDev->SetDataFormat(&c_dfDIMouse);
        hr=pInputDev->SetCooperativeLevel(hWnd,DISCL_EXCLUSIVE | DISCL_FOREGROUND);
        DIPROPDWORD dipdw;

        dipdw.diph.dwSize       = sizeof(DIPROPDWORD);
    dipdw.diph.dwHeaderSize = sizeof(DIPROPHEADER);
        dipdw.diph.dwObj        = 0;
    dipdw.diph.dwHow        = DIPH_DEVICE;
    dipdw.dwData            = 500;

    pInputDev->SetProperty( DIPROP_BUFFERSIZE, &dipdw.diph ) ;
        pInputDev->Acquire();
}

void ReadMouse()//检测鼠标
{
        DIMOUSESTATE mouse_stat;
        ZeroMemory(&mouse_stat,sizeof(mouse_stat));
        HRESULT hr;
        hr=pInputDev->GetDeviceState( sizeof(DIMOUSESTATE), &mouse_stat );
        mousex+=mouse_stat.lX;
        mousey+=mouse_stat.lY;
}
[em24]

hdm2968

up

hdm2968

up

bigbook2000

你也不说问题，拿东西考人啊

hdm2968

这样的初始化的hr全部正常，但：hr=pInputDev->GetDeviceState( sizeof(DIMOUSESTATE), &mouse_stat );
就出错了：）

bigbook2000

你真是问一句说一句，那地方出错很正常，不是所有的情况下都是返回S_OK的，你要把你遇到的问题讲明白

bigbook2000

If the method succeeds, the return value is DI_OK.

If the method fails, the return value can be one of the following error values:


DIERR_INPUTLOST Access to the input device has been lost. It must be reacquired.

DIERR_INVALIDPARAM An invalid parameter was passed to the returning function, or the object was not in a state that permitted the function to be called. This value is equal to the E_INVALIDARG standard Component Object Model (COM) return value.

DIERR_NOTACQUIRED The operation cannot be performed unless the device is acquired.

DIERR_NOTINITIALIZED The object has not been initialized.

E_PENDING Data is not yet available.

bigbook2000

其中 DIERR_INPUTLOST 和 DIERR_NOTACQUIRED 应该是属于正常的错误，前者表示设备丢失了重新调用一下Acquire()就可以了，后者有可能你的循环取状态值的函数调用了，但你的Acquire()函数还没来的及调用，等一下就好了。

要特别注意的是第一种情况，如果你在DISCL_FOREGROUND状态下调试程序，设了断点的话，通常运行到断点的时候返回的是 DIERR_INPUTLOST ，因为这时候你的程序实际上切换到后台去了，需要在窗口即获得时重新Acquire()。

偷懒的做法就是
hr=pInputDev->GetDeviceState( sizeof(DIMOUSESTATE), &mouse_stat );
if ( FAILED(hr) ) pInputDev->Acquire( );

hdm2968

那我上面的代码齐全了吗？