C++ getch()函数不阻塞的原因，求各位大 佬解决方案。
代码如下：
/**************************
* Includes
*
**************************/
#include <windows.h>
#include <gl/gl.h>
#include <stdio.h>
#include <conio.h>
#include <iostream>
#include <fstream>
/**************************
* Function Declarations
*
**************************/
LRESULT CALLBACK WndProc (HWND hWnd, UINT message,
WPARAM wParam, LPARAM lParam);
void EnableOpenGL (HWND hWnd, HDC *hDC, HGLRC *hRC);
void DisableOpenGL (HWND hWnd, HDC hDC, HGLRC hRC);
double xfl=0.0f,yfl=0.0f;
double playerx=0.0f,playery=0.0f;
int keyb=0;
/**************************
* WinMain
*
**************************/
int WINAPI WinMain (HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int iCmdShow){
WNDCLASS wc;
HWND hWnd;
HDC hDC;
HGLRC hRC;
MSG msg;
BOOL bQuit = FALSE;
float theta = 0.0f;
/* register window class */
wc.style = CS_OWNDC;
wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon (NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor (NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH) GetStockObject (BLACK_BRUSH);
wc.lpszMenuName = NULL;
wc.lpszClassName = "GLSample";
RegisterClass (&wc);
/* create main window */
hWnd = CreateWindow (
"GLSample", "OpenGL Sample",
WS_CAPTION | WS_POPUPWINDOW | WS_VISIBLE,
0, 0, 512, 512,
NULL, NULL, hInstance, NULL);
/* enable OpenGL for the window */
EnableOpenGL (hWnd, &hDC, &hRC);
/* program main loop */
while (!bQuit){
/* check for messages */
if (PeekMessage (&msg, NULL, 0, 0, PM_REMOVE)){
/* handle or dispatch messages */
if (msg.message == WM_QUIT){
bQuit = TRUE;
}
else{
TranslateMessage (&msg);
DispatchMessage (&msg);
}
}
else{
/* OpenGL animation code goes here */
glClearColor (0.0f, 0.0f, 0.0f, 0.0f);
glClear (GL_COLOR_BUFFER_BIT);
glPushMatrix ();
glBegin (GL_LINES);
for(double xl=-248;xl<256;xl+=16){
xfl=xl/256;
glColor3f(0.5f,0.5f,0.5f); glVertex2f(xfl,-0.96875f);
glColor3f(0.5f,0.5f,0.5f); glVertex2f(xfl,0.96875f);
}
for(double yl=-248;yl<256;yl+=16){
yfl=yl/256;
glColor3f(0.5f,0.5f,0.5f); glVertex2f(-0.96875f,yfl);
glColor3f(0.5f,0.5f,0.5f); glVertex2f(0.96875f,yfl);
}
glEnd ();
glBegin (GL_POINTS);
glColor3f(1.0f,1.0f,1.0f); glVertex2f(playerx-0.0234375f,playery-0.0234375f);
glColor3f(1.0f,1.0f,1.0f); glVertex2f(playerx+0.0234375f,playery-0.0234375f);
glColor3f(1.0f,1.0f,1.0f); glVertex2f(playerx-0.0234375f,playery+0.0234375f);
glColor3f(1.0f,1.0f,1.0f); glVertex2f(playerx+0.0234375f,playery+0.0234375f);
glEnd ();
glPopMatrix ();
SwapBuffers (hDC);
kbhit();
keyb=getch();
if(keyb==87||keyb==119){
playery+=0.0625f;
}
if(keyb==65||keyb==97){
playerx-=0.0625f;
}
if(keyb==83||keyb==115){
playery-=0.0625f;
}
if(keyb==68||keyb==100){
playerx+=0.0625f;
}
//playerx+=0.000625f;
Sleep (1);
}
}
/* shutdown OpenGL */
DisableOpenGL (hWnd, hDC, hRC);
/* destroy the window explicitly */
DestroyWindow (hWnd);
return msg.wParam;
}
/********************
* Window Procedure
*
********************/
LRESULT CALLBACK WndProc (HWND hWnd, UINT message,WPARAM wParam, LPARAM lParam){
switch (message)
{
case WM_CREATE:
return 0;
case WM_CLOSE:
PostQuitMessage (0);
return 0;
case WM_DESTROY:
return 0;
case WM_KEYDOWN:
switch (wParam)
{
case VK_ESCAPE:
PostQuitMessage(0);
return 0;
}
return 0;
default:
return DefWindowProc (hWnd, message, wParam, lParam);
}
}
/*******************
* Enable OpenGL
*
*******************/
void EnableOpenGL (HWND hWnd, HDC *hDC, HGLRC *hRC){
PIXELFORMATDESCRIPTOR pfd;
int iFormat;
/* get the device context (DC) */
*hDC = GetDC (hWnd);
/* set the pixel format for the DC */
ZeroMemory (&pfd, sizeof (pfd));
pfd.nSize = sizeof (pfd);
pfd.nVersion = 1;
pfd.dwFlags = PFD_DRAW_TO_WINDOW |
PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
pfd.iPixelType = PFD_TYPE_RGBA;
pfd.cColorBits = 24;
pfd.cDepthBits = 16;
pfd.iLayerType = PFD_MAIN_PLANE;
iFormat = ChoosePixelFormat (*hDC, &pfd);
SetPixelFormat (*hDC, iFormat, &pfd);
/* create and enable the render context (RC) */
*hRC = wglCreateContext( *hDC );
wglMakeCurrent( *hDC, *hRC );
}
/******************
* Disable OpenGL
*
******************/
void DisableOpenGL (HWND hWnd, HDC hDC, HGLRC hRC){
wglMakeCurrent (NULL, NULL);
wglDeleteContext (hRC);
ReleaseDC (hWnd, hDC);
}
编译正常通过，但运行时在107行时没有阻塞，似乎也没有返回值。
我是在取消第121行的注释时发现了问题，即：
/**************************
* Includes
*
**************************/
#include <windows.h>
#include <gl/gl.h>
#include <stdio.h>
#include <conio.h>
#include <iostream>
#include <fstream>
/**************************
* Function Declarations
*
**************************/
LRESULT CALLBACK WndProc (HWND hWnd, UINT message,
WPARAM wParam, LPARAM lParam);
void EnableOpenGL (HWND hWnd, HDC *hDC, HGLRC *hRC);
void DisableOpenGL (HWND hWnd, HDC hDC, HGLRC hRC);
double xfl=0.0f,yfl=0.0f;
double playerx=0.0f,playery=0.0f;
int keyb=0;
/**************************
* WinMain
*
**************************/
int WINAPI WinMain (HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int iCmdShow){
WNDCLASS wc;
HWND hWnd;
HDC hDC;
HGLRC hRC;
MSG msg;
BOOL bQuit = FALSE;
float theta = 0.0f;
/* register window class */
wc.style = CS_OWNDC;
wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon (NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor (NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH) GetStockObject (BLACK_BRUSH);
wc.lpszMenuName = NULL;
wc.lpszClassName = "GLSample";
RegisterClass (&wc);
/* create main window */
hWnd = CreateWindow (
"GLSample", "OpenGL Sample",
WS_CAPTION | WS_POPUPWINDOW | WS_VISIBLE,
0, 0, 512, 512,
NULL, NULL, hInstance, NULL);
/* enable OpenGL for the window */
EnableOpenGL (hWnd, &hDC, &hRC);
/* program main loop */
while (!bQuit){
/* check for messages */
if (PeekMessage (&msg, NULL, 0, 0, PM_REMOVE)){
/* handle or dispatch messages */
if (msg.message == WM_QUIT){
bQuit = TRUE;
}
else{
TranslateMessage (&msg);
DispatchMessage (&msg);
}
}
else{
/* OpenGL animation code goes here */
glClearColor (0.0f, 0.0f, 0.0f, 0.0f);
glClear (GL_COLOR_BUFFER_BIT);
glPushMatrix ();
glBegin (GL_LINES);
for(double xl=-248;xl<256;xl+=16){
xfl=xl/256;
glColor3f(0.5f,0.5f,0.5f); glVertex2f(xfl,-0.96875f);
glColor3f(0.5f,0.5f,0.5f); glVertex2f(xfl,0.96875f);
}
for(double yl=-248;yl<256;yl+=16){
yfl=yl/256;
glColor3f(0.5f,0.5f,0.5f); glVertex2f(-0.96875f,yfl);
glColor3f(0.5f,0.5f,0.5f); glVertex2f(0.96875f,yfl);
}
glEnd ();
glBegin (GL_POINTS);
glColor3f(1.0f,1.0f,1.0f); glVertex2f(playerx-0.0234375f,playery-0.0234375f);
glColor3f(1.0f,1.0f,1.0f); glVertex2f(playerx+0.0234375f,playery-0.0234375f);
glColor3f(1.0f,1.0f,1.0f); glVertex2f(playerx-0.0234375f,playery+0.0234375f);
glColor3f(1.0f,1.0f,1.0f); glVertex2f(playerx+0.0234375f,playery+0.0234375f);
glEnd ();
glPopMatrix ();
SwapBuffers (hDC);
kbhit();
keyb=getch();
if(keyb==87||keyb==119){
playery+=0.0625f;
}
if(keyb==65||keyb==97){
playerx-=0.0625f;
}
if(keyb==83||keyb==115){
playery-=0.0625f;
}
if(keyb==68||keyb==100){
playerx+=0.0625f;
}
playerx+=0.000625f;
Sleep (1);
}
}
/* shutdown OpenGL */
DisableOpenGL (hWnd, hDC, hRC);
/* destroy the window explicitly */
DestroyWindow (hWnd);
return msg.wParam;
}
/********************
* Window Procedure
*
********************/
LRESULT CALLBACK WndProc (HWND hWnd, UINT message,WPARAM wParam, LPARAM lParam){
switch (message)
{
case WM_CREATE:
return 0;
case WM_CLOSE:
PostQuitMessage (0);
return 0;
case WM_DESTROY:
return 0;
case WM_KEYDOWN:
switch (wParam)
{
case VK_ESCAPE:
PostQuitMessage(0);
return 0;
}
return 0;
default:
return DefWindowProc (hWnd, message, wParam, lParam);
}
}
/*******************
* Enable OpenGL
*
*******************/
void EnableOpenGL (HWND hWnd, HDC *hDC, HGLRC *hRC){
PIXELFORMATDESCRIPTOR pfd;
int iFormat;
/* get the device context (DC) */
*hDC = GetDC (hWnd);
/* set the pixel format for the DC */
ZeroMemory (&pfd, sizeof (pfd));
pfd.nSize = sizeof (pfd);
pfd.nVersion = 1;
pfd.dwFlags = PFD_DRAW_TO_WINDOW |
PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
pfd.iPixelType = PFD_TYPE_RGBA;
pfd.cColorBits = 24;
pfd.cDepthBits = 16;
pfd.iLayerType = PFD_MAIN_PLANE;
iFormat = ChoosePixelFormat (*hDC, &pfd);
SetPixelFormat (*hDC, iFormat, &pfd);
/* create and enable the render context (RC) */
*hRC = wglCreateContext( *hDC );
wglMakeCurrent( *hDC, *hRC );
}
/******************
* Disable OpenGL
*
******************/
void DisableOpenGL (HWND hWnd, HDC hDC, HGLRC hRC){
wglMakeCurrent (NULL, NULL);
wglDeleteContext (hRC);
ReleaseDC (hWnd, hDC);
}
在运行这一段取消121行注释的代码时，弹窗里的用四个点表示的玩家位置会不断向右，也就是说getch并没有阻塞。
附加信息：
#include<conio.h>
#include<iostream>
using namespace std;
int keyb=0;
int main(void){
while(1){
kbhit();
keyb=getch();
cout<<keyb<<endl;
}
return 0;
}
在这段代码中getch阻塞并正常返回输入字符的ascii值。
如果不是getch函数的问题，也希望在座及时指出错误，有任何有帮助的回答，感激不尽！
这里的gl.h文件已经下载，如果有表述不清晰之处，请及时来询问。再次感谢。
