win32自绘按钮，使用GDI+（一）

第一次写随笔，我本来想将win32窗口的标题栏设置成渐变色，像这样的效果

但发现找不到设置标题栏属性的api，SetWindowLong也只是增减窗口的固定的样式而已。所以想到一个思路，把标题栏去掉，自己绘制一个标题栏，包括标题栏上的按钮都自己来绘制创建。这里用到了gdi+，对于这个库也是刚接触到的。

最后程序实现的效果如下。

代码：

 #ifndef ULONG_PTR
 #define ULONG_PTR unsigned long*
 #endif
 #include <windows.h>
 //#include <objidl.h>
 #include <gdiplus.h>
 using namespace Gdiplus;
 #pragma comment (lib,"Gdiplus.lib")
 #define ID_BUTTON1 1
 #define ID_BUTTON2 2
 HINSTANCE hInst;

 void LoadBkImge(HDC hdc)
 {
     Graphics graphics(hdc);
    Image image(L"pic1.png");
    graphics.DrawImage(&image,,);
 }

 void FillRec(HDC hdc,Rect myRect,Color* colors,float *positions,int i)
 {
     Graphics graphics(hdc);
    //多彩渐变色
     LinearGradientBrush myLinearGradientBrush(
        myRect,
        Color(,,,),
        Color(,,,),
        LinearGradientModeVertical
        );//LinearGradientModeHorizontal*/

       myLinearGradientBrush.SetInterpolationColors(colors, positions, i);
       graphics.FillRectangle(&myLinearGradientBrush,myRect);
 } 

 LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM); 

 int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE, PSTR, INT iCmdShow)
 {
    HWND                hWnd;
    MSG                 msg;
    WNDCLASS            wndClass;
    GdiplusStartupInput gdiplusStartupInput;
    ULONG_PTR           gdiplusToken;
    hInst=hInstance;

    // Initialize GDI+.
    GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL); 

    wndClass.style          = CS_HREDRAW | CS_VREDRAW|DS_CENTER;
    wndClass.lpfnWndProc    = WndProc;
    wndClass.cbClsExtra     = ;
    wndClass.cbWndExtra     = ;
    wndClass.hInstance      = hInstance;
    wndClass.hIcon          = LoadIcon(NULL, IDI_APPLICATION);
    wndClass.hCursor        = LoadCursor(NULL, IDC_ARROW);
    wndClass.hbrBackground  = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wndClass.lpszMenuName   = NULL;
    wndClass.lpszClassName  = TEXT("Gdiplustest"); 

    RegisterClass(&wndClass); 

    hWnd = CreateWindow(
       TEXT("Gdiplustest"),
       TEXT("Gdiplustest"),
       WS_OVERLAPPED|WS_POPUP,
       CW_USEDEFAULT,
       CW_USEDEFAULT,
       ,
       ,
       NULL,
       NULL,
       hInstance,
       NULL);                 

    ShowWindow(hWnd, iCmdShow);
    UpdateWindow(hWnd); 

    while(GetMessage(&msg, NULL, , ))
    {
       TranslateMessage(&msg);
       DispatchMessage(&msg);
    } 

    GdiplusShutdown(gdiplusToken);
    return msg.wParam;
 }  

 LRESULT CALLBACK WndProc(HWND hWnd, UINT message,
    WPARAM wParam, LPARAM lParam)
 {
    static HDC   hdc;
    static HWND hButton1,hButton2;
    PAINTSTRUCT  ps;
    LPDRAWITEMSTRUCT pdis;

    switch(message)
    {
    case WM_CREATE:
        {
            //窗口居中显示
            int scrWidth,scrHeight;
            RECT rect;
            scrWidth=GetSystemMetrics(SM_CXSCREEN);
            scrHeight=GetSystemMetrics(SM_CYSCREEN);
            GetWindowRect(hWnd,&rect);
            rect.left=(scrWidth-rect.right)/;
            rect.top=(scrHeight-rect.bottom)/;
            SetWindowPos(hWnd,HWND_TOP,rect.left,rect.top,rect.right,rect.bottom,SWP_SHOWWINDOW);
            hButton1=CreateWindow("button","",WS_CHILD|WS_VISIBLE|BS_OWNERDRAW,,,,,hWnd,(HMENU)ID_BUTTON1,hInst,NULL);
            hButton2=CreateWindow("button","",WS_CHILD|WS_VISIBLE|BS_OWNERDRAW,,,,,hWnd,(HMENU)ID_BUTTON2,hInst,NULL);

            //
            hdc=GetDC(hWnd);
            return ;
        }
    case WM_SIZE:
        return ;
    case WM_PAINT:
        {
         hdc = BeginPaint(hWnd, &ps);
         LoadBkImge(hdc);
         Rect myRect(,,,);

         //
        Color colors[]={
        Color(,,),
        Color(,,),
        Color(,,),
        Color(,,),
        Color(,,),
        Color(,,)
        };
       float positions[]={
        0.0f,
        0.2f,
        0.4f,
        0.6f,
        0.8f,
        1.0f
       };
         FillRec(hdc,myRect,colors,positions,);
         Graphics graphics(hdc);
         Pen pen1(Color(,,,));
         Pen pen2(Color(,,,));
         Pen pen3(Color(,,,));
         graphics.DrawLine(&pen1,,,,);
         graphics.DrawLine(&pen2,,,,);
         graphics.DrawLine(&pen3,,,,);

       EndPaint(hWnd, &ps);
       return ;
        }
    case WM_COMMAND:
        {
            switch(wParam)
             {
            case ID_BUTTON1:
                {
                    ShowWindow(hWnd,SW_SHOWMINIMIZED);
                    break;
                }
            case ID_BUTTON2:
                 {
                     PostQuitMessage();
                     break;
                 }
                 //
            }

        return ;

        }

    case WM_DRAWITEM:
        {

             pdis=(LPDRAWITEMSTRUCT)lParam;
             //SetBkMode(pdis->hDC, TRANSPARENT );
             FillRect(pdis->hDC,&pdis->rcItem,NULL);
             FrameRect(pdis->hDC,&pdis->rcItem,(HBRUSH)GetStockObject(BLACK_BRUSH));

             int cx=pdis->rcItem.right-pdis->rcItem.bottom;
             int cy=pdis->rcItem.bottom-pdis->rcItem.top;

             switch(pdis->CtlID)
             {

                 case ID_BUTTON1:
                 {
                         Graphics graphics(pdis->hDC);
                         Rect rectt(,,,);
                         Color colors[]={
                         Color(,,),
                         Color(,,),
                         Color(,,),
                         Color(,,),
                         };
                         float positions[]={
                         0.0f,
                         0.333333f,
                         0.666666f,
                         1.0f
                         };
                         FillRec(pdis->hDC,rectt,colors,positions,);
                         {
                         SolidBrush  m_pBrush(Color(,,,));
                         PointF point1(3.0f, 6.5f);
                         PointF point2(12.0f, 6.5f);
                         PointF point3(12.0f, 8.50f);
                         PointF point4(3.0f, 8.50f);
                         PointF points[] = {point1, point2, point3,point4};
                         graphics.FillPolygon(&m_pBrush, points, , FillModeAlternate);
                         }

                         break;
                 }

                 case ID_BUTTON2:
                 {
                     Graphics graphics(pdis->hDC);
                     Rect rectt(,,,);
                     Color colors[]={
                     Color(,,),
                     Color(,,),
                     Color(,,),
                     Color(,,),
                     };
                     float positions[]={
                         0.0f,
                         0.33333f,
                         0.66633f,
                         1.0f
                     };
                     FillRec(pdis->hDC,rectt,colors,positions,);

                     SolidBrush  m_pBrush(Color(,,,));
                     //
                     PointF point1(2.0f, 4.0f);
                     PointF point2(4.0f, 2.0f);
                     PointF point3(13.0f, 11.0f);
                     PointF point4(11.0f, 13.0f);
                     PointF points[] = {point1, point2, point3,point4};
                     graphics.FillPolygon(&m_pBrush, points, , FillModeAlternate);
                     //
                     PointF point5(13.0f, 4.0f);
                     PointF point6(11.0f, 2.0f);
                     PointF point7(2.0f, 11.0f);
                     PointF point8(4.0f, 13.0f);

                     PointF points2[] = {point5, point6, point7,point8    };
                     graphics.FillPolygon(&m_pBrush, points2, , FillModeAlternate);
                     }
                 break;
             }
           //if (pdis->itemState & ODS_SELECTED)
               // InvertRect (pdis->hDC, &pdis->rcItem) ;

               //  Draw a focus rectangle if the button has the focus

           if (pdis->itemState & ODS_FOCUS)
           {
                pdis->rcItem.left   += cx /  ;
                pdis->rcItem.top    += cy /  ;
                pdis->rcItem.right  -= cx /  ;
                pdis->rcItem.bottom -= cy /  ;

                DrawFocusRect (pdis->hDC, &pdis->rcItem) ;
           }
           return  ;
        }

    case WM_DESTROY:
       PostQuitMessage();
       return ;
    case WM_LBUTTONDOWN:
       SendMessage(hWnd,WM_NCLBUTTONDOWN,HTCAPTION,);
       return ;
    default:
       return DefWindowProc(hWnd, message, wParam, lParam);
    }
 }

说明：

这里有一个严重的问题，如何设置按钮的背景透明？临时的解决办法是将按钮填充相同的渐变色。如画的标题栏的五种渐变色的position数组值为

       float positions[]={
        0.0f,
        0.2f,
        0.4f,
        0.6f,
        0.8f,
        1.0f
       };

颜色为

         Color colors[]={
         Color(,,),
         Color(,,),
         Color(,,),
         Color(,,),
         Color(,,),
         Color(,,)
        };

根据坐标计算出按钮的渐变色颜色和位置分别为

              Color colors[]={
                 Color(,,),
                 Color(,,),
                 Color(,,),
                 Color(,,),
             };
             float positions[]={
                 0.0f,
                 0.333333f,
                 0.666666f,
                 1.0f
             };

这种方法看起来挺笨的，所以最后留两个问题。

问题一：如何设置系统菜单栏为渐变色？

问题二：按钮背景如何透明？

参考：杂七杂八找了很多资料