VC++ WIN32 sdk实现按钮自绘详解.

2021-07-16 02:40:59

网上找了很多,可只是给出代码,没有详细解释,不便初学者理解.我就抄回冷饭.把这个再拿出来说说.

实例图片:

首先建立一个标准的Win32 Application 工程.选择a simple Win32 Application.

然后建立我们的资源文件首先新建一个对话框资源,资源ID改为IDD_MAIN_DLG

然后在其上新建一个按钮控件资源ID改为IDC_ODBUTTON,此按钮的styles中必须选中owenerdraw属性.

然后将其保存为.rc的资源文件.并将其导入我们的工程.同理新建一个图标文件资源ID改为IDI_OWNERDRAW保存为.ico的图标然后导入.

准备工作做完了下面开始写代码.

首先声明如下全局变量.

#include "stdafx.h"
#include "resource.h"

   HINSTANCE odInst = NULL;  //接收程序实例的句柄
HWND hMainWnd = NULL;     //接收主窗口的句柄
HWND hDlgNow = NULL;      //接收对话框的句柄
static HICON hOwnerDrawIcon = NULL;  //用作自绘按钮的图标
static LONG prev_proc;                 //储存按钮先前的回调函数
static HICON hIcon = NULL;           //对话框图标句柄

然后开始写WinMain()函数

int APIENTRY WinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,
                     int       nCmdShow)
{
     // TODO: Place code here.
    odInst = hInstance;

    WNDCLASS  wc;
    wc.style         = 0;
    wc.lpfnWndProc   = (WNDPROC)ODWndProc; //定义一个窗口默认函数,这里我们会交由默认窗口函数处理
    wc.cbClsExtra    = 0;
    wc.cbWndExtra    = 0;
    wc.hInstance     = hInstance;
    wc.hIcon         = LoadIcon(odInst,MAKEINTRESOURCE(IDI_OWNERDRAW));
    wc.hCursor       = NULL;
    wc.hbrBackground = 0;
    wc.lpszClassName = "OwnerDraw";
    wc.lpszMenuName     = NULL;

    RegisterClass(&wc);

MSG msg;

    HWND onlywin= FindWindow("OwnerDraw","MyOwnerDraw");

    if (onlywin)
        {
        ExitProcess(1);
        }

    hMainWnd=CreateWindow("OwnerDraw","MyOwnerDraw",WS_OVERLAPPEDWINDOW,
                CW_USEDEFAULT,0,CW_USEDEFAULT,0,NULL,NULL,hInstance,NULL);


    if (!hMainWnd)
        {
            return FALSE;
        }


    hDlgNow = DoMainDlg(hMainWnd);
    ShowWindow(hDlgNow, nCmdShow);

    while(GetMessage(&msg, NULL, 0, 0))
    {
        if (NULL == hDlgNow || !IsDialogMessage(hDlgNow, &msg))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    return msg.wParam;
}

首先注册一个标准的窗口类,的WNDCLASS结构体,默认的窗口过程为ODWndProc.其定义如下.

LRESULT CALLBACK ODWndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
return DefWindowProc(hWnd, message, wParam, lParam);//返回系统默认的窗口过程
}

然后判断有无相同实例存在如有则结束之

HWND onlywin= FindWindow("OwnerDraw","MyOwnerDraw");

    if (onlywin)
        {
        ExitProcess(1);
        }

接下来创建主窗口

hMainWnd=CreateWindow("OwnerDraw","MyOwnerDraw",WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT,0,CW_USEDEFAULT,0,NULL,NULL,hInstance,NULL);

需要注意的是我们这里并不调用ShowWindow()和UpdateWindow();因为我们不需要显示主窗口

hDlgNow = DoMainDlg(hMainWnd);
ShowWindow(hDlgNow, nCmdShow);

这里调用DoMainDlg函数创建一个对话框并显示之. DoMainDlg函数实现如下.

HWND DoMainDlg(HWND parent)
{
    DWORD dwErr;
    HWND hRet = CreateDialog(odInst, (LPCTSTR)IDD_MAIN_DLG, parent, (DLGPROC)MainDlgProc);
    if(hRet == NULL)
        dwErr = GetLastError();

    return hRet;

}

最后为消息循环

while(GetMessage(&msg, NULL, 0, 0))
    {
        if (NULL == hDlgNow || !IsDialogMessage(hDlgNow, &msg))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

其中IsDialogMessage(hDlgNow, &msg)主要作用是把指定对话框的消息,路由给其处理.

下面是对话框窗口的默认消息响应回调函数MainDlgProc

我这里主要讲响应WM_DRAWITEM消息与WM_INITDIALOG..

首先是响应WM_INITDIALOG

case WM_INITDIALOG:

            if(hIcon == NULL)
                hIcon = LoadIcon(odInst, MAKEINTRESOURCE(IDI_OWNERDRAW));

            if(hOwnerDrawIcon == NULL)
                hOwnerDrawIcon = (HICON)LoadImage(odInst,
                                        MAKEINTRESOURCE(IDI_OWNERDRAW),
                                        IMAGE_ICON,
                                        38,
                                        38,
                                        0);
            prev_proc = SetWindowLongPtr(GetDlgItem(hDlg, IDC_ODBUTTON), GWLP_WNDPROC, (LONG)ButtWindProc);

            SendMessage(hDlg, WM_SETICON, ICON_SMALL, (LPARAM)hIcon);

            SetFocus(GetDlgItem(hDlg, IDC_ODBUTTON));


            break;

首先为对话框加载一个图标,我这里图省事全部都用了一个图标,在实际应用中.可以随需要更换.

然后是为自绘按钮加载图标.接下来改变默认的自绘按钮的窗口过程.将原按钮过程存与prev_proc中.

最后发送WM_SETICON消息设置对话框图标和设置焦点.

接下来是响应WM_DRAWITEM消息,需要说明的是这个消息必须要设置了BS_OWNERDRAW

我们用记事本打开我们的对话框资源文件会看到类似下面的设置

IDD_MAIN_DLG DIALOG DISCARDABLE  0, 0, 250, 142
STYLE DS_MODALFRAME | WS_POPUP | WS_CAPTION | WS_SYSMENU
CAPTION "Dialog"
FONT 10, "System"
BEGIN
    DEFPUSHBUTTON   "OK",IDOK,193,7,50,14
    PUSHBUTTON      "Cancel",IDCANCEL,193,24,50,14
    CONTROL         "OwnerDraw",IDC_ODBUTTON,"Button",BS_OWNERDRAW |
                    WS_TABSTOP,49,31,79,26
END

此处资源文件中的BS_OWNERDRAW即对应创建按钮时选中的Ownerdraw属性.之所以这样作是因为只有这样

对话框才能响应WM_DRAWITEM消息.下面为代码.

case WM_DRAWITEM:
            {
                LPDRAWITEMSTRUCT lpDIS = (LPDRAWITEMSTRUCT) lParam;
                //声明一个指向DRAWITEMSTRUCT结构体的指针并将其指向存储着按钮构造信息的lParam

                if(lpDIS->CtlID != IDC_ODBUTTON)
                    return (0);

                HDC dc = lpDIS->hDC; //用于按钮绘制的DC
                BOOL bIsPressed  = (lpDIS->itemState & ODS_SELECTED);
                BOOL bIsFocused  = (lpDIS->itemState & ODS_FOCUS);
                BOOL bIsDisabled = (lpDIS->itemState & ODS_DISABLED);
                BOOL bDrawFocusRect = !(lpDIS->itemState & ODS_NOFOCUSRECT);
                //判断按钮各种状态的BOOL值
                RECT itemRect = lpDIS->rcItem; //按钮的矩形区域

                SetBkMode(dc, TRANSPARENT); //设置绘制按钮时的背景状态
                if (bIsFocused)  //判断按钮是否获得了焦点并对其边框进行处理
                {
                    HBRUSH br = CreateSolidBrush(RGB(0,0,0));
                    FrameRect(dc, &itemRect, br);
                    InflateRect(&itemRect, -1, -1);
                    DeleteObject(br);
                } // if

                COLORREF crColor = GetSysColor(COLOR_BTNFACE);//得到系统按钮颜色

                HBRUSH    brBackground = CreateSolidBrush(crColor);//创建画刷

                FillRect(dc, &itemRect, brBackground);//绘制按钮

                DeleteObject(brBackground);

                // 这里画被按下去的按钮
                if (bIsPressed)
                {
                    HBRUSH brBtnShadow = CreateSolidBrush(GetSysColor(COLOR_BTNSHADOW));
                    FrameRect(dc, &itemRect, brBtnShadow);
                    DeleteObject(brBtnShadow);
                }

                else //如果没有被按下就这样画
                {
                    UINT uState = DFCS_BUTTONPUSH |
                        ((bIsPressed) ? DFCS_PUSHED : 0);

                    DrawFrameControl(dc, &itemRect, DFC_BUTTON, uState);
                }

                char sTitle[100];
                GetWindowText(GetDlgItem(hDlg, IDC_ODBUTTON), sTitle, 100);//得到按钮的文本

                RECT captionRect = lpDIS->rcItem;//把文本的区域设置为按钮区域


                BOOL bHasTitle = (sTitle[0] !='/0');//按钮上是否有文本存在

//这里画按钮上的图标,具体实现见下面
                 (GetDlgItem(hDlg, IDC_ODBUTTON), &dc, bHasTitle,
                    &lpDIS->rcItem, &captionRect, bIsPressed, bIsDisabled);



                if (bHasTitle)//如果按钮有文本标题
                {
                    // 按钮被按下的处理
                    if (bIsPressed)
                        OffsetRect(&captionRect, 1, 1);

                    // 将文本居中
                    RECT centerRect = captionRect;
                    DrawText(dc, sTitle, -1, &captionRect, DT_WORDBREAK | DT_CALCRECT|DT_CENTER);
                    LONG captionRectWidth = captionRect.right - captionRect.left;
                    LONG captionRectHeight = captionRect.bottom - captionRect.top;
                    LONG centerRectWidth = centerRect.right - centerRect.left;
                    LONG centerRectHeight = centerRect.bottom - centerRect.top;
                    OffsetRect(&captionRect, (centerRectWidth - captionRectWidth)/2, (centerRectHeight - captionRectHeight)/2);



                    SetBkMode(dc, TRANSPARENT);

                    if (bIsDisabled)//如果按钮被禁用
                    {
                        OffsetRect(&captionRect, 1, 1);
                        SetTextColor(dc, ::GetSysColor(COLOR_3DHILIGHT));
                        DrawText(dc, sTitle, -1, &captionRect, DT_WORDBREAK | DT_CENTER);
                        OffsetRect(&captionRect, -1, -1);
                        SetTextColor(dc, ::GetSysColor(COLOR_3DSHADOW));
                        DrawText(dc, sTitle, -1, &captionRect, DT_WORDBREAK | DT_CENTER);
                    }
                    else //如果没被禁用正常画
                    {
                        SetTextColor(dc, ::GetSysColor(COLOR_BTNTEXT));
                        SetBkColor(dc, ::GetSysColor(COLOR_BTNFACE));
                        DrawText(dc, sTitle, -1, &captionRect, DT_WORDBREAK | DT_CENTER);
                    }

                }

                // 画按钮得到焦点时的虚线方框
                if (bIsFocused && bDrawFocusRect)
                {
                    RECT focusRect = itemRect;
                    InflateRect(&focusRect, -3, -3);
                    DrawFocusRect(dc, &focusRect);
                } // if
                return (TRUE);
            }
            break;

到此WM_DRAWITEM消息响应完毕.下面我们看看DrawTheIcon这个函数.

static void DrawTheIcon(HWND hButtonWnd, HDC* dc, BOOL bHasTitle, RECT* rpItem, RECT* rpTitle, BOOL bIsPressed, BOOL bIsDisabled)
{
    RECT    rImage;
    PrepareImageRect(hButtonWnd, bHasTitle, rpItem, rpTitle, bIsPressed, 38, 38, &rImage);

    // 调用API函数按准备好的形式将图片画到按钮上
    DrawState(    *dc,
        NULL,
        NULL,
        (LPARAM)hOwnerDrawIcon,
        0,
        rImage.left,
        rImage.top,
        (rImage.right - rImage.left),
        (rImage.bottom - rImage.top),
        (bIsDisabled ? DSS_DISABLED : DSS_NORMAL) | DST_ICON);
}

还有其中的PrepareImageRect函数

static void PrepareImageRect(HWND hButtonWnd, BOOL bHasTitle, RECT* rpItem, RECT* rpTitle, BOOL bIsPressed, DWORD dwWidth, DWORD dwHeight, RECT* rpImage)
{
    RECT rBtn;

    CopyRect(rpImage, rpItem);


    GetClientRect(hButtonWnd, &rBtn);
    if (bHasTitle == FALSE)//如果按钮上有文本内容
    {
        // 使图片水平居中
        LONG rpImageWidth = rpImage->right - rpImage->left;
        rpImage->left += ((rpImageWidth - (long)dwWidth)/2);
    }
    else
    {   //控制图片与焦点方框内部
        LONG rpTitleWidth = rpTitle->right - rpTitle->left;
        rpTitle->right = rpTitleWidth - dwWidth - 30;
        rpTitle->left = 30;
        rpImage->left = rBtn.right - dwWidth - 22;

        LONG rpImageHeight = rpImage->bottom - rpImage->top;
        rpImage->top += ((rpImageHeight - (long)dwHeight)/2);
    }
    if (bIsPressed)//按钮被按下的处理
        OffsetRect(rpImage, 1, 1);

}

行了到这里主要的工作都作完了还要说明的就是ButtWindProc这个按钮窗口的回调函数.写它的主要目的是为了

实现按钮的连续单击,在此函数中我们处理了WM_LBUTTONDBLCLK鼠标双击事件,并将其转化为一个单击事件.像这样:

LRESULT CALLBACK ButtWindProc(
                              HWND hWnd,                            //window handle
                              UINT message,                         // type of message
                              WPARAM wParam,                        // additional information
                              LPARAM lParam)                        //additional information
{
    switch (message)
    {
    case WM_LBUTTONDBLCLK:
        PostMessage(hWnd, WM_LBUTTONDOWN, wParam, lParam);
        break;

    }
    //将不做处理的消息路由给原默认函数
    return CallWindowProc((WNDPROC)prev_proc, hWnd, message, wParam, lParam);

}

下面只需再响应WM_SETICON, WM_SYSCOMMAND, WM_COMMAND.这三个没什么好说的.前两个交由系统默认过程处理,最后一个对应对话框上的确定和取消,都是销毁窗口的行为.

case WM_SETICON:
                DefWindowProc(hDlg, message, wParam, lParam);
            break;

    case WM_SYSCOMMAND:
                {
                    return DefWindowProc(hDlg, message, wParam, lParam);
                }
    case WM_COMMAND:
                switch (LOWORD(wParam))
                {
                case IDCANCEL:
                case IDOK:

                    DestroyIcon(hOwnerDrawIcon);

                    PostQuitMessage(0);
                    return TRUE;
                }//switch
                break;

本文部分内容参考自http://www.codeproject.com/buttonctrl/nativewin32xpthemes.asp

本实例源代码http://geniusdot.googlepages.com/new.rar

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