①CheckDlgButton

Changes the check state of a button control

②CheckRadioButton

Adds a check mark to (checks) a specified radio button in a group and removes a check mark from (clears) all other radio buttons in the group

③IsDlgButtonChecked

The IsDlgButtonChecked function determines whether a button control is checked or whether a three-state button control is checked, unchecked, or indeterminate 

#define _CRT_SECURE_NO_WARNINGS#include 
     
      #include 
      
       #include "resource.h"int CDECL MessageBoxPrintf(TCHAR *szCaption, TCHAR *szFormat, ...){    TCHAR szBuffer[1024];    va_list pArgList;    va_start(pArgList, szFormat);    _vsntprintf(szBuffer, sizeof(szBuffer) / sizeof(TCHAR), szFormat, pArgList);    va_end(pArgList);    return MessageBox(NULL, szBuffer, szCaption, 0);}int CALLBACK DialogProc(HWND hwndDlg,    UINT uMsg,    WPARAM wParam,    LPARAM lParam){    switch (uMsg)    {    case WM_COMMAND:        switch (LOWORD(wParam))        {        case WM_INITDIALOG:            return TRUE;        case IDOK :            CheckDlgButton(hwndDlg, IDC_CHECK1, BST_CHECKED);            CheckRadioButton(hwndDlg, IDC_RADIO1, IDC_RADIO3, IDC_RADIO2);            if (IsDlgButtonChecked(hwndDlg, IDC_RADIO2) == BST_CHECKED)                MessageBox(NULL, TEXT(""), TEXT("确定"), 0);            return TRUE;        case IDNO :            CheckDlgButton(hwndDlg, IDC_CHECK1, BST_UNCHECKED);            CheckRadioButton(hwndDlg, IDC_RADIO1, IDC_RADIO3, IDC_RADIO1);            if (IsDlgButtonChecked(hwndDlg, IDC_RADIO2) == BST_CHECKED)                MessageBox(NULL, TEXT(""), TEXT("取消"), 0);            return TRUE;        case IDCANCEL :            EndDialog(hwndDlg, 0);            PostQuitMessage(0);            return TRUE;        }    }    return FALSE;}int CALLBACK WinMain(HINSTANCE hInstance,    HINSTANCE hPrevInstance,    LPSTR lpCmdLine,    int nCmdShow){    HWND hwnd;    MSG message;    hwnd = CreateDialog(hInstance, MAKEINTRESOURCE(IDD_DIALOG1), NULL, DialogProc);    if (hwnd == NULL)        MessageBoxPrintf(TEXT(""), TEXT("%d"), GetLastError());    ShowWindow(hwnd, nCmdShow);    UpdateWindow(hwnd);    while (GetMessage(&message, NULL, 0, 0))    {        TranslateMessage(&message);        DispatchMessage(&message);    }    return message.wParam;}