在实际开发中,我们往往需要知道哪个按钮被选中了,才能进行下一步的操作。例如对于一组单选按钮,只有一个选项能被选中,最好的办法是将这组按钮作为参数传入一个函数,通过函数返回值判断哪个按钮被选中了。
但遗憾的是,在Windows中不能一次性获得一组按钮的选中状态,只能一个一个地遍历。复选框也是如此。
可以通过SendMessage函数发送BM_GETCHECK消息来获取按钮的选中状态,返回 BST_CHECKED 表示按钮被选中,返回 BST_UNCHECKED 是未被选中。
SendMessage 原型为: LRESULT WINAPI SendMessage( HWND hWnd, //窗口(控件)句柄 UINT Msg, //消息类型 WPARAM wParam, //附加消息1 LPARAM lParam //附加消息2 );
注意:发送 BM_GETCHECK 消息时,wParam 和 lParam 两个参数必须都为 0。
下面的代码会判断一个按钮是否被选中。如果被选中,那么会获取按钮文本并保存到缓冲区:
if( SendMessage(hCheckBox, BM_GETCHECK, 0, 0) == BST_CHECKED ){ GetWindowText(hCheckBox, szBuffer, 10); }
我们对上节的例子进行改进,添加一个提交按钮,当用户点击该按钮时,获取用户的选项:
//窗口过程 LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) { PAINTSTRUCT ps; HDC hdc; static HFONT hFont; //逻辑字体 //单选按钮 static HWND labSex; //静态文本框--性别 static HWND radioMale; //单选按钮--男 static HWND radioFemale; //单选按钮--女 static HWND radioOther; //单选按钮 static HWND labMarriage; //静态文本框--婚姻状况 static HWND radioMarried; //单选按钮--已婚 static HWND radioSingle; //单选按钮--未婚 static HWND radioSecrecy; //单选按钮--保密 //复选框 static HWND labPet; //静态文本框--你的宠物 static HWND checkboxDog; //复选框--狗 static HWND checkboxCat; //复选框--猫 static HWND checkboxFish; //复选框--鱼 static HWND checkboxOther; //复选框--其他 //分组框控件 static HWND hGroupSex; //分组框--性别 static HWND hRadioMale; //单选按钮--男 static HWND hRadioFemale; //单选按钮--女 //设置缓冲区 static TCHAR szBufSex[10]; //保存性别 static TCHAR szBufMarriage[10]; //保存婚姻状况 static TCHAR szBufPet[20]; //保存宠物 static TCHAR szBufSubmit[100]; //保存提交时显示的文本 static TCHAR szBufTmp[10]; //临时缓冲区 /** * 为了节省空间,这里省略了各种控件句柄的定义 * 这里的代码与上节相同,请参考上节代码 **/ static HWND btnSubmit; //按钮控件 int wmId, wmEvent; switch (message) { case WM_CREATE: btnSubmit = CreateWindow(TEXT("button"), TEXT("提 交"), WS_CHILD | WS_VISIBLE | WS_BORDER | BS_PUSHBUTTON, 20, 250, 200, 36, hWnd, (HMENU)13, hInst, NULL ); hFont = CreateFont( -14, -7, 0, 0, 400, FALSE, FALSE, FALSE, DEFAULT_CHARSET, OUT_CHARACTER_PRECIS, CLIP_CHARACTER_PRECIS, DEFAULT_QUALITY, FF_DONTCARE, TEXT("微软雅黑") ); //选择性别 labSex = CreateWindow( TEXT("static"), TEXT("你的性别:"), WS_CHILD | WS_VISIBLE | SS_CENTERIMAGE | SS_RIGHT/*文字居右*/, 10, 10, 80, 26, hWnd, (HMENU)1, hInst, NULL ); radioMale = CreateWindow( TEXT("button"), TEXT("男"), WS_CHILD | WS_VISIBLE | BS_LEFT/*文字居左*/ | BS_AUTORADIOBUTTON /*单选按钮*/ | WS_GROUP, 95, 10, 50, 26, hWnd, (HMENU)2, hInst, NULL ); radioFemale = CreateWindow( TEXT("button"), TEXT("女"), WS_CHILD | WS_VISIBLE | BS_LEFT | BS_AUTORADIOBUTTON, 150, 10, 50, 26, hWnd, (HMENU)3, hInst, NULL ); radioOther = CreateWindow( TEXT("button"), TEXT("其他"), WS_CHILD | WS_VISIBLE | BS_LEFT/*文字居左*/ | BS_AUTORADIOBUTTON /*单选按钮*/ , 205, 10, 50, 26, hWnd, (HMENU)4, hInst, NULL ); //选择婚姻状况 labMarriage = CreateWindow( TEXT("static"), TEXT("婚姻状况:"), WS_CHILD | WS_VISIBLE | SS_CENTERIMAGE | SS_RIGHT, 10, 40, 80, 26, hWnd, (HMENU)14, hInst, NULL ); radioMarried = CreateWindow( TEXT("button"), TEXT("已婚"), WS_CHILD | WS_VISIBLE | BS_LEFT | BS_AUTORADIOBUTTON | WS_GROUP, 95, 40, 65, 26, hWnd, (HMENU)5, hInst, NULL ); radioSingle = CreateWindow( TEXT("button"), TEXT("未婚"), WS_CHILD | WS_VISIBLE | BS_LEFT | BS_AUTORADIOBUTTON, 165, 40, 65, 26, hWnd, (HMENU)6, hInst, NULL ); radioSecrecy = CreateWindow( TEXT("button"), TEXT("保密"), WS_CHILD | WS_VISIBLE | BS_LEFT | BS_AUTORADIOBUTTON, 235, 40, 100, 26, hWnd, (HMENU)7, hInst, NULL ); //你的宠物 labPet = CreateWindow( TEXT("static"), TEXT("你的宠物:"), WS_CHILD | WS_VISIBLE | SS_CENTERIMAGE | SS_RIGHT, 10, 70, 80, 26, hWnd, (HMENU)18, hInst, NULL ); checkboxDog = CreateWindow( TEXT("button"), TEXT("狗"), WS_CHILD | WS_VISIBLE | BS_LEFT | BS_AUTOCHECKBOX/*复选框*/, 95, 70, 50, 26, hWnd, (HMENU)9, hInst, NULL ); checkboxCat = CreateWindow( TEXT("button"), TEXT("猫"), WS_CHILD | WS_VISIBLE | BS_LEFT | BS_AUTOCHECKBOX, 150, 70, 50, 26, hWnd, (HMENU)10, hInst, NULL ); checkboxFish = CreateWindow( TEXT("button"), TEXT("鱼"), WS_CHILD | WS_VISIBLE | BS_LEFT | BS_AUTOCHECKBOX, 205, 70, 50, 26, hWnd, (HMENU)11, hInst, NULL ); checkboxOther = CreateWindow( TEXT("button"), TEXT("蜘蛛"), WS_CHILD | WS_VISIBLE | BS_LEFT | BS_AUTOCHECKBOX, 260, 70, 65, 26, hWnd, (HMENU)12, hInst, NULL ); SendMessage(btnSubmit, WM_SETFONT, (WPARAM)hFont, 0); SendMessage(labSex, WM_SETFONT, (WPARAM)hFont, 0); SendMessage(radioMale, WM_SETFONT, (WPARAM)hFont, 0); SendMessage(radioFemale, WM_SETFONT, (WPARAM)hFont, 0); SendMessage(radioOther, WM_SETFONT, (WPARAM)hFont, 0); SendMessage(labMarriage, WM_SETFONT, (WPARAM)hFont, 0); SendMessage(radioMarried, WM_SETFONT, (WPARAM)hFont, 0); SendMessage(radioSingle, WM_SETFONT, (WPARAM)hFont, 0); SendMessage(radioSecrecy, WM_SETFONT, (WPARAM)hFont, 0); SendMessage(labPet, WM_SETFONT, (WPARAM)hFont, 0); SendMessage(checkboxDog, WM_SETFONT, (WPARAM)hFont, 0); SendMessage(checkboxCat, WM_SETFONT, (WPARAM)hFont, 0); SendMessage(checkboxFish, WM_SETFONT, (WPARAM)hFont, 0); SendMessage(checkboxOther, WM_SETFONT, (WPARAM)hFont, 0); //创建分组框控件 hGroupSex = CreateWindow( TEXT("button"), TEXT("你的性别"), WS_CHILD | WS_VISIBLE | BS_GROUPBOX, 20, 120, 300, 70, hWnd, (HMENU)21, hInst, NULL ); //接下来添加单选按钮 hRadioMale = CreateWindow( TEXT("button"), TEXT("男"), WS_CHILD | WS_VISIBLE | BS_LEFT | BS_AUTORADIOBUTTON /*单选按钮*/, 15, 30, 50, 26, hGroupSex /*父窗口为 GroupBox 控件*/, (HMENU)22, hInst, NULL ); hRadioFemale = CreateWindow( TEXT("button"), TEXT("女"), WS_CHILD | WS_VISIBLE | BS_LEFT | BS_AUTORADIOBUTTON, 80, 30, 50, 26, hGroupSex, (HMENU)23, hInst, NULL ); break; case WM_COMMAND: wmId = LOWORD(wParam); wmEvent = HIWORD(wParam); if (wmEvent == BN_CLICKED) { switch (wmId) { //获取性别 case 2: case 3: case 4: GetWindowText((HWND)lParam, szBufSex, 10); break; //获取婚姻状况 case 5: case 6: case 7: GetWindowText((HWND)lParam, szBufMarriage, 10); break; //获取宠物 case 9: case 10: case 11: case 12: memset(szBufPet, 0, sizeof(szBufPet));//清空szBuffer内容 //是否选中狗 if (SendMessage(checkboxDog, BM_GETCHECK, 0, 0) == BST_CHECKED) { GetWindowText(checkboxDog, szBufTmp, 10); StringCchPrintf(szBufPet,20, TEXT("%s %s"), szBufPet, szBufTmp); } //是否选中猫 if (SendMessage(checkboxCat, BM_GETCHECK, 0, 0) == BST_CHECKED) { GetWindowText(checkboxCat, szBufTmp, 10); StringCchPrintf(szBufPet, 20, TEXT("%s %s"), szBufPet, szBufTmp); } //是否选中鱼 if (SendMessage(checkboxFish, BM_GETCHECK, 0, 0) == BST_CHECKED) { GetWindowText(checkboxFish, szBufTmp, 10); StringCchPrintf(szBufPet, 20, TEXT("%s %s"), szBufPet, szBufTmp); } //是否选中其他 if (SendMessage(checkboxOther, BM_GETCHECK, 0, 0) == BST_CHECKED) { GetWindowText(checkboxOther, szBufTmp, 10); StringCchPrintf(szBufPet, 20, TEXT("%s %s"), szBufPet, szBufTmp); } break; //点击提交按钮 case 13: StringCchPrintf(szBufSubmit,100, TEXT("性别:%s\n婚姻状况:%s\r\n你的宠物:%s"), szBufSex, szBufMarriage, szBufPet); MessageBox(hWnd, szBufSubmit, TEXT("信息提示"), MB_ICONINFORMATION); break; default: return DefWindowProc(hWnd, message, wParam, lParam); } } return DefWindowProc(hWnd, message, wParam, lParam); case WM_PAINT: hdc = BeginPaint(hWnd, &ps); // TODO: 在此添加任意绘图代码... EndPaint(hWnd, &ps); break; case WM_DESTROY: PostQuitMessage(0); break; default: return DefWindowProc(hWnd, message, wParam, lParam); } return 0; }