为什么我不能用DirectInput获取键盘?
Why can I not acquire the keyboard with DirectInput?
我今天刚开始使用DirectInput8，在Windows 7 Ultimate n上使用DirectInput8和MinGW。我开始用一个简单的程序来报告当前每秒下降的键(只是代码，不是可读的键)。然而，我甚至不能在它出错之前获得键盘:
#define _WIN32_WINNT 0x0601
#include <dinput.h>
//link to dinput8.lib and dxguid.lib
int main() {
IDirectInput8 *dinput;
DirectInput8Create(GetModuleHandle(nullptr), DIRECTINPUT_VERSION, IID_IDirectInput8, (void **)&dinput, nullptr);
IDirectInputDevice8 *kb;
dinput->CreateDevice(GUID_SysKeyboard, &kb, nullptr);
kb->SetDataFormat(&c_dfDIKeyboard);
kb->SetCooperativeLevel(GetConsoleWindow(), DISCL_FOREGROUND | DISCL_NONEXCLUSIVE);
kb->Acquire(); //fails with DIERR_INVALIDPARAM
}
我省略了错误检查，但是发生的是每个调用都成功(通过FAILED宏的判断)直到Acquire()。该呼叫失败，错误为DIERR_INVALIDPARAM。我看了MSDN页面和整个网络，但我找不到任何理由它会失败，基于它出现和工作之前的一切。
为了更好地衡量，我还尝试循环Acquire()调用，直到它成功，然后在运行时使用窗口和键盘，但是程序在运行的所有时间内从未成功获取键盘。我怎样才能成功获得键盘?
尝试在控制台程序中直接输入键盘和操纵杆
使用直接输入并不需要有一个窗口的句柄。您可以在窗口句柄的参数中使用null。
代替:
kb->SetCooperativeLevel(GetConsoleWindow(), DISCL_FOREGROUND | DISCL_NONEXCLUSIVE);
使用:
kb->SetCooperativeLevel(NULL, DISCL_FOREGROUND | DISCL_NONEXCLUSIVE);
下面是一个示例程序，当按下'a'和'd'键时，使用直接输入来显示这些键。当这些键被保持300毫秒时，它会重复这些键。该示例程序也是高分辨率计数器的一个很好的示例。不需要在Visual Studio中添加属性来添加库dinput8。和dxguide . Lib。程序顶部的#pragma注释代码行为您完成了这项工作。
#include <dinput.h>
#include <iostream>
#include <Windows.h>
#pragma comment(lib,"dinput8.lib")
#pragma comment(lib,"dxguid.lib")
using std::cout;
using std::endl;
LPDIRECTINPUT8 di;
LPDIRECTINPUTDEVICE8 keyboard;
class CTimer
{
public:
CTimer() {
QueryPerformanceFrequency(&mqFreq);
}
~CTimer() {}
void Start() {
QueryPerformanceCounter(&mqStart);
}
void End() {
QueryPerformanceCounter(&mqEnd);
}
double GetTimeInSeconds() {
return (mqEnd.QuadPart - mqStart.QuadPart)/(double)mqFreq.QuadPart;
}
double GetTimeInMilliseconds() {
return (1.0e3*(mqEnd.QuadPart - mqStart.QuadPart))/mqFreq.QuadPart;
}
double GetTimeInMicroseconds() {
return (1.0e6*(mqEnd.QuadPart - mqStart.QuadPart))/mqFreq.QuadPart;
}
double GetTimeInNanoseconds() {
return (1.0e9*(mqEnd.QuadPart - mqStart.QuadPart))/mqFreq.QuadPart;
}
private:
LARGE_INTEGER mqStart;
LARGE_INTEGER mqEnd;
LARGE_INTEGER mqFreq;
};
HRESULT initializedirectinput8() {
HRESULT hr;
// Create a DirectInput device
if (FAILED(hr = DirectInput8Create(GetModuleHandle(NULL), DIRECTINPUT_VERSION,
IID_IDirectInput8, (VOID**)&di, NULL))) {
return hr;
}
}
void createdikeyboard() {
di->CreateDevice(GUID_SysKeyboard, &keyboard, NULL);
keyboard->SetDataFormat(&c_dfDIKeyboard);
keyboard->SetCooperativeLevel(NULL,DISCL_FOREGROUND | DISCL_EXCLUSIVE);
keyboard->Acquire();
}
void destroydikeyboard() {
keyboard->Unacquire();
keyboard->Release();
}
#define keydown(name,key) (name[key] & 0x80)
void main() {
HRESULT hr;
BYTE dikeys[256];
CTimer timeint;
CTimer timekeywaspressedclass;
double gettime;
double lastkeywasa=false;
double timekeywaspressed=0;
bool lasttimetherewasakeypress=false;
bool akeywaspressed=false;
initializedirectinput8();
createdikeyboard();
hr=keyboard->GetDeviceState(256,dikeys);
timeint.Start();
while (!keydown(dikeys,DIK_ESCAPE)) {
timeint.End();
gettime=timeint.GetTimeInMilliseconds();
if (gettime >=5) {
hr=keyboard->GetDeviceState(256,dikeys);
akeywaspressed=false;
if (keydown(dikeys,DIK_A)) {
akeywaspressed=true;
if (timekeywaspressed >=300) {
cout << "a";
lasttimetherewasakeypress=false;
}
}
if (keydown(dikeys,DIK_D)) {
akeywaspressed=true;
if (timekeywaspressed >=300) {
cout << "d";
lasttimetherewasakeypress=false;
}
}
if (lasttimetherewasakeypress==false && akeywaspressed==true) {
timekeywaspressedclass.Start();
timekeywaspressed=0;
lasttimetherewasakeypress=true;
}
if (lasttimetherewasakeypress==true && akeywaspressed==true) {
timekeywaspressedclass.End();
gettime=timekeywaspressedclass.GetTimeInMilliseconds();
timekeywaspressed+=gettime;
timekeywaspressedclass.Start();
}
if (akeywaspressed==false) {
lasttimetherewasakeypress=false;
timekeywaspressed=0;
}
} // end if (gettime >=5)
} // end while
destroydikeyboard();
} // end main
这是一个操纵杆的控制台程序示例。
#include <dinput.h>
#include <iostream>
#include <Windows.h>
#pragma comment(lib,"dinput8.lib")
#pragma comment(lib,"dxguid.lib")
using std::cout;
using std::endl;
LPDIRECTINPUT8 di;
LPDIRECTINPUTDEVICE8 joystick;
LPDIRECTINPUTDEVICE8 keyboard;
DIJOYSTATE2 js;
BOOL CALLBACK enumCallback(const DIDEVICEINSTANCE* instance, VOID* context);
BOOL CALLBACK enumAxesCallback(const DIDEVICEOBJECTINSTANCE* instance, VOID* context);
HRESULT selectjoystick() {
HRESULT hr;
// Look for the first simple joystick we can find.
if (FAILED(hr = di->EnumDevices(DI8DEVCLASS_GAMECTRL, enumCallback,
NULL, DIEDFL_ATTACHEDONLY))) {
return hr;
}
// Make sure we got a joystick
if (joystick == NULL) {
// printf("Joystick not found.n");
return E_FAIL;
}
}
DIDEVCAPS capabilities;
HRESULT setjoystickproperties() {
HRESULT hr;
// Set the data format to "simple joystick" - a predefined data format
//
// A data format specifies which controls on a device we are interested in,
// and how they should be reported. This tells DInput that we will be
// passing a DIJOYSTATE2 structure to IDirectInputDevice::GetDeviceState().
if (FAILED(hr = joystick->SetDataFormat(&c_dfDIJoystick2))) {
return hr;
}
// Set the cooperative level to let DInput know how this device should
// interact with the system and with other DInput applications.
if (FAILED(hr = joystick->SetCooperativeLevel(NULL, DISCL_EXCLUSIVE |
DISCL_FOREGROUND))) {
return hr;
}
// Determine how many axis the joystick has (so we don't error out setting
// properties for unavailable axis)
capabilities.dwSize = sizeof(DIDEVCAPS);
if (FAILED(hr = joystick->GetCapabilities(&capabilities))) {
return hr;
}
}
BOOL CALLBACK enumCallback(const DIDEVICEINSTANCE* instance, VOID* context)
{
HRESULT hr;
// Obtain an interface to the enumerated joystick.
hr = di->CreateDevice(instance->guidInstance, &joystick, NULL);
// If it failed, then we can't use this joystick. (Maybe the user unplugged
// it while we were in the middle of enumerating it.)
if (FAILED(hr)) {
return DIENUM_CONTINUE;
}
// Stop enumeration. Note: we're just taking the first joystick we get. You
// could store all the enumerated joysticks and let the user pick.
return DIENUM_STOP;
}
HRESULT enumaxes() {
HRESULT hr;
// Enumerate the axes of the joyctick and set the range of each axis. Note:
// we could just use the defaults, but we're just trying to show an example
// of enumerating device objects (axes, buttons, etc.).
if (FAILED(hr = joystick->EnumObjects(enumAxesCallback, NULL, DIDFT_AXIS))) {
return hr;
}
}
BOOL CALLBACK enumAxesCallback(const DIDEVICEOBJECTINSTANCE* instance, VOID* context)
{
HWND hDlg = (HWND)context;
DIPROPRANGE propRange;
propRange.diph.dwSize = sizeof(DIPROPRANGE);
propRange.diph.dwHeaderSize = sizeof(DIPROPHEADER);
propRange.diph.dwHow = DIPH_BYID;
propRange.diph.dwObj = instance->dwType;
propRange.lMin = -1000;
propRange.lMax = +1000;
// Set the range for the axis
if (FAILED(joystick->SetProperty(DIPROP_RANGE, &propRange.diph))) {
return DIENUM_STOP;
}
return DIENUM_CONTINUE;
}
HRESULT polljoy() {
HRESULT hr;
if (joystick == NULL) {
return S_OK;
}
// Poll the device to read the current state
hr = joystick->Poll();
if (FAILED(hr)) {
// DInput is telling us that the input stream has been
// interrupted. We aren't tracking any state between polls, so
// we don't have any special reset that needs to be done. We
// just re-acquire and try again.
hr = joystick->Acquire();
while (hr == DIERR_INPUTLOST) {
hr = joystick->Acquire();
}
// If we encounter a fatal error, return failure.
if ((hr == DIERR_INVALIDPARAM) || (hr == DIERR_NOTINITIALIZED)) {
return E_FAIL;
}
// If another application has control of this device, return successfully.
// We'll just have to wait our turn to use the joystick.
if (hr == DIERR_OTHERAPPHASPRIO) {
return S_OK;
}
}
// Get the input's device state
if (FAILED(hr = joystick->GetDeviceState(sizeof(DIJOYSTATE2), &js))) {
return hr; // The device should have been acquired during the Poll()
}
return S_OK;
}
class CTimer
{
public:
CTimer() {
QueryPerformanceFrequency(&mqFreq);
}
~CTimer() {}
void Start() {
QueryPerformanceCounter(&mqStart);
}
void End() {
QueryPerformanceCounter(&mqEnd);
}
double GetTimeInSeconds() {
return (mqEnd.QuadPart - mqStart.QuadPart)/(double)mqFreq.QuadPart;
}
double GetTimeInMilliseconds() {
return (1.0e3*(mqEnd.QuadPart - mqStart.QuadPart))/mqFreq.QuadPart;
}
double GetTimeInMicroseconds() {
return (1.0e6*(mqEnd.QuadPart - mqStart.QuadPart))/mqFreq.QuadPart;
}
double GetTimeInNanoseconds() {
return (1.0e9*(mqEnd.QuadPart - mqStart.QuadPart))/mqFreq.QuadPart;
}
private:
LARGE_INTEGER mqStart;
LARGE_INTEGER mqEnd;
LARGE_INTEGER mqFreq;
};
HRESULT initializedirectinput8() {
HRESULT hr;
// Create a DirectInput device
if (FAILED(hr = DirectInput8Create(GetModuleHandle(NULL), DIRECTINPUT_VERSION,
IID_IDirectInput8, (VOID**)&di, NULL))) {
return hr;
}
}
void createdikeyboard() {
di->CreateDevice(GUID_SysKeyboard, &keyboard, NULL);
keyboard->SetDataFormat(&c_dfDIKeyboard);
keyboard->SetCooperativeLevel(NULL,DISCL_FOREGROUND | DISCL_EXCLUSIVE);
keyboard->Acquire();
}
void destroydikeyboard() {
keyboard->Unacquire();
keyboard->Release();
}
void closejoystick() {
if (joystick) {
joystick->Unacquire();
}
if (joystick) {
joystick->Release();
}
}
#define keydown(name,key) (name[key] & 0x80)
void main() {
HRESULT hr;
CTimer pollintclass;
hr=initializedirectinput8();
createdikeyboard();
hr=selectjoystick();
hr=setjoystickproperties();
hr=enumaxes();
bool endloop=false;
double gettime;
BYTE dikeys[256];
pollintclass.Start();
while (endloop==false) {
pollintclass.End();
gettime=pollintclass.GetTimeInMilliseconds();
if (gettime >=5) {
hr=keyboard->GetDeviceState(256,dikeys);
if (FAILED(hr))
keyboard->Acquire();
if (keydown(dikeys,DIK_ESCAPE))
endloop=true;
polljoy();
cout << "joy x-axis=" << js.lX << " " << "joy y-axis=" << js.lY << endl;
pollintclass.Start();
}
}
destroydikeyboard();
closejoystick();
}
您尝试过DISCL_BACKGROUND而不是DISCL_FOREGROUND吗?
实际上，当我将错误从与控制台窗口(可见存在)关联更改为我在SetCooperativeLevel()调用中创建的窗口时，错误会神奇地消失。为什么控制台窗口不能使用我不知道，所以我将暂时不接受这个问题，而不是回答问题的人，但这确实解决了问题。
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