OpenGL 使用GLEW没有返回错误，可是GLEW_宏和wglChoosePixelFormatARB函数都不可用这是怎么回事？

[Silent_Lamb]

#include <GL/glew.h>
#include <GL/wglew.h>
#include <windows.h>
//  下面是OpenGL环境初始化函数
void EnableOpenGL(HWND hwnd, HDC* hDC, HGLRC* hRC)
{
    PIXELFORMATDESCRIPTOR pfd =		//	PixelFormatDescriptor, PFD structure
		{
			sizeof(PIXELFORMATDESCRIPTOR),	//WORD  nSize;
			1,				//WORD  nVersion  should be 1
			PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER,   //DWORD dwFlags, properties of the pixel buffer	//Flags
			PFD_TYPE_RGBA,		//BYTE  iPixelType, type of pixel data					//The kind of framebuffer. RGBA or palette.
			32,			//BYTE  cColorBits, number of color bitplanes in each color buffer	//Colordepth of the framebuffer.
			0,			//BYTE  cRedBits, the number of red bitplanes in each RGBA color buffer
			0,			//BYTE  cRedShift, the shift count for red bitplanes in each RGBA color buffer
 			0,			//BYTE  cGreenBits
 			0,			//BYTE  cGreenShift
 			0,			//BYTE  cBlueBits
			0,			//BYTE  cBlueShift
			0,			//BYTE  cAlphaBits, the number of alpha bitplanes in each RGBA color buffer. Alpha bitplanes are not supported.
			0,			//BYTE  cAlphaShift, the shift count for alpha bitplanes in each RGBA color buffer. Alpha bitplanes are not supported.
			0,			//BYTE  cAccumBits, the total number of bitplanes in the accumulation buffer
			0,			//BYTE  cAccumRedBits
			0,			//BYTE  cAccumGreenBits
			0,			//BYTE  cAccumBlueBits
			0,			//BYTE  cAccumAlphaBits
			24,			//BYTE  cDepthBits, the depth of the depth (z-axis) buffer	//Number of bits for the depthbuffer
			8,			//BYTE  cStencilBits, the depth of the stencil buffer		//Number of bits for the stencilbuffer
			0,			//BYTE  cAuxBuffers, the number of auxiliary buffers. Not supported	//Number of Aux buffers in the framebuffer.
			PFD_MAIN_PLANE,		//BYTE  iLayerType, ignored, no longer used
			0,			//BYTE  bReserved, the number of overlay and underlay planes
			0,			//DWORD dwLayerMask, ignored, no longer used
			0,			//DWORD dwVisibleMask, the transparent color or index of an underlay plane
			0			//DWORD dwDamageMask, ignored, no longer used
		};

    int iFormat;

    *hDC = GetDC(hwnd);

    iFormat = ChoosePixelFormat(*hDC, &pfd);

    SetPixelFormat(*hDC, iFormat, &pfd);

    /* create and enable the render context (RC) */
    *hRC = wglCreateContext(*hDC);                // 建立一个假的OpenGL设备环境
    wglMakeCurrent( *hDC , *hRC );

    GLenum err;
    err = glewInit();
    if (GLEW_OK != err)       // 初始化GLEW，没有返回错误
    {
        //	Problem: glewInit failed, something is seriously wrong.
        char szErrorMsg[20];
        sprintf( szErrorMsg , "Error: %s\n" , glewGetErrorString(err) );
        MessageBox( hwnd, szErrorMsg , "GLEW initialization error" , MB_OK );
    }
    else
    {
        char szErrorMsg[20];
        sprintf( szErrorMsg , "GLEW: %s\n" , glewGetErrorString(err) );
        MessageBox( hwnd, szErrorMsg , "OpenGL" , MB_OK );
    }


    char openGLVersion[20];
    sprintf(openGLVersion,"OpenGL version: %s", (char*)glGetString(GL_VERSION) );
    MessageBox(hwnd,openGLVersion,"OpenGL version",MB_OK);      // 显示OpenGL版本是3.0

 /*   if (GLEW_ARB_vertex_program)    // 为什么调用 GLEW_ 宏也编译出错?
    {
      // It is safe to use the ARB_vertex_program extension here.
        MessageBox(hwnd,"It is safe to use the ARB_vertex_program extension here","ARB_vertex_program is OK",MB_OK);
    }
*/
/*    if (glewIsSupported("GL_ARB_vertex_program")) // 这样是可以的
    {
        MessageBox(hwnd,"It is safe to use the ARB_vertex_program extension here","ARB_vertex_program is OK",MB_OK);
    }
*/
    const int attribList[] =
    {
        WGL_DRAW_TO_WINDOW_ARB, GL_TRUE,
        WGL_SUPPORT_OPENGL_ARB, GL_TRUE,
        WGL_DOUBLE_BUFFER_ARB, GL_TRUE,
        WGL_PIXEL_TYPE_ARB, WGL_TYPE_RGBA_ARB,
        WGL_COLOR_BITS_ARB, 32,
        WGL_DEPTH_BITS_ARB, 24,
        WGL_STENCIL_BITS_ARB, 8,
        0,        //End
    };
    int pixelFormat;
    UINT numFormats;
//   wglChoosePixelFormatARB(*hDC, attribList, NULL, 1, &pixelFormat, &numFormats);    // 直接用不行，编译提示错误
    PFNWGLCHOOSEPIXELFORMATARBPROC pChoosePixelFormat;
    pChoosePixelFormat = (PFNWGLCHOOSEPIXELFORMATARBPROC)wglGetProcAddress("wglChoosePixelFormatARB");   // 用这个函数获得函数指针就可以用了
    pChoosePixelFormat(*hDC, attribList, NULL, 1, &pixelFormat, &numFormats);
    SetPixelFormat(*hDC, pixelFormat , NULL );
}

我这是在Code::Block下编译的，因为我的是64位win7系统，VC6.0不能支持64位的 glew.lib 文件，改用32位版本的 glew.lib 提示invalid machine type ；而在Code::Block 下虽然也不支持64位的 glew.lib，但是32位的编译通过，不知道是不是因为这样导致glew没有起作用。可是之前我忘了把假的OpenGL设备环境设为当前，也就是少了这句wglMakeCurrent( *hDC , *hRC ); glew返回了错误missing GL version，加上那句以后没有返回错误，这说明 glew 应该是有用的呀。。好奇怪

[Silent_Lamb]

问题解决了。我在32位虚拟机下面运行没有问题，GLEW_宏和wglChoosePixelFormatARB函数都可以用。就是因为64位系统下面不能用32位的glew32.lib文件