为什么我的单选按钮不起作用？

Question

我正在 Visual C++ 2005 中开发 MFC 对话框应用程序。我的单选按钮是 m_Small、m_Medium 和 m_Large。 它们都没有在我的 m_Summary 编辑框中显示应有的内容。 可能出什么问题了？

这是我的代码。

    // Pizza_ProgramDlg.cpp : implementation file
//

#include "stdafx.h"
#include "Pizza_Program.h"
#include "Pizza_ProgramDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#endif


// CAboutDlg dialog used for App About

class CAboutDlg : public CDialog
{
public:
    CAboutDlg();

// Dialog Data
    enum { IDD = IDD_ABOUTBOX };

    protected:
    virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support

// Implementation
protected:
    DECLARE_MESSAGE_MAP()
};

CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
    CDialog::DoDataExchange(pDX);
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
END_MESSAGE_MAP()


// CPizza_ProgramDlg dialog




CPizza_ProgramDlg::CPizza_ProgramDlg(CWnd* pParent /*=NULL*/)
    : CDialog(CPizza_ProgramDlg::IDD, pParent)
    , m_Name(_T(""))
    , m_Address(_T(""))
    , m_Phone(_T(""))
    , m_Summary(_T(""))
    , m_Extra(FALSE)
    , m_Pepperoni(FALSE)
    , m_Sausage(FALSE)
    , m_Peppers(FALSE)
    , m_Mushrooms(FALSE)
    , m_Onions(FALSE)
    , m_Eatin(0)
    , m_Medium(0)
    , m_Large(0)
    , m_Takeout(0)
    , m_Delivery(0)
    , m_Small(0)
{
    m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CPizza_ProgramDlg::DoDataExchange(CDataExchange* pDX)
{
    CDialog::DoDataExchange(pDX);
    DDX_Text(pDX, IDC_EDIT_NAME, m_Name);
    DDV_MaxChars(pDX, m_Name, 1000);
    DDX_Text(pDX, IDC_EDIT_ADDRESS, m_Address);
    DDV_MaxChars(pDX, m_Address, 1000);
    DDX_Text(pDX, IDC_EDIT_PHONE, m_Phone);
    DDV_MaxChars(pDX, m_Phone, 1000);
    DDX_Text(pDX, IDC_EDIT_SUMMARY, m_Summary);
    DDV_MaxChars(pDX, m_Summary, 1000);
    DDX_Check(pDX, IDC_CHECK_EXTRA, m_Extra);
    DDX_Check(pDX, IDC_CHECK_PEPPERONI, m_Pepperoni);
    DDX_Check(pDX, IDC_CHECK_SAUSAGE, m_Sausage);
    DDX_Check(pDX, IDC_CHECK_PEPPERS, m_Peppers);
    DDX_Check(pDX, IDC_CHECK_MUSHROOMS, m_Mushrooms);
    DDX_Check(pDX, IDC_CHECK_ONIONS, m_Onions);
}

BEGIN_MESSAGE_MAP(CPizza_ProgramDlg, CDialog)
    ON_WM_SYSCOMMAND()
    ON_WM_PAINT()
    ON_WM_QUERYDRAGICON()
    //}}AFX_MSG_MAP
    ON_EN_CHANGE(IDC_EDIT_SUMMARY, &CPizza_ProgramDlg::OnEnChangeEditSummary)
    ON_BN_CLICKED(IDOK, &CPizza_ProgramDlg::OnBnClickedOk)
    ON_BN_CLICKED(IDC_BUTTON_PROCESS, &CPizza_ProgramDlg::OnBnClickedButtonProcess)
END_MESSAGE_MAP()


// CPizza_ProgramDlg message handlers

BOOL CPizza_ProgramDlg::OnInitDialog()
{
    CDialog::OnInitDialog();

    // Add "About..." menu item to system menu.

    // IDM_ABOUTBOX must be in the system command range.
    ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
    ASSERT(IDM_ABOUTBOX < 0xF000);

    CMenu* pSysMenu = GetSystemMenu(FALSE);
    if (pSysMenu != NULL)
    {
        CString strAboutMenu;
        strAboutMenu.LoadString(IDS_ABOUTBOX);
        if (!strAboutMenu.IsEmpty())
        {
            pSysMenu->AppendMenu(MF_SEPARATOR);
            pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
        }
    }

    // Set the icon for this dialog.  The framework does this automatically
    //  when the application's main window is not a dialog
    SetIcon(m_hIcon, TRUE);         // Set big icon
    SetIcon(m_hIcon, FALSE);        // Set small icon

    // TODO: Add extra initialization here

    return TRUE;  // return TRUE  unless you set the focus to a control
}

void CPizza_ProgramDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
    if ((nID & 0xFFF0) == IDM_ABOUTBOX)
    {
        CAboutDlg dlgAbout;
        dlgAbout.DoModal();
    }
    else
    {
        CDialog::OnSysCommand(nID, lParam);
    }
}

// If you add a minimize button to your dialog, you will need the code below
//  to draw the icon.  For MFC applications using the document/view model,
//  this is automatically done for you by the framework.

void CPizza_ProgramDlg::OnPaint()
{
    if (IsIconic())
    {
        CPaintDC dc(this); // device context for painting

        SendMessage(WM_ICONERASEBKGND, reinterpret_cast<WPARAM>(dc.GetSafeHdc()), 0);

        // Center icon in client rectangle
        int cxIcon = GetSystemMetrics(SM_CXICON);
        int cyIcon = GetSystemMetrics(SM_CYICON);
        CRect rect;
        GetClientRect(&rect);
        int x = (rect.Width() - cxIcon + 1) / 2;
        int y = (rect.Height() - cyIcon + 1) / 2;

        // Draw the icon
        dc.DrawIcon(x, y, m_hIcon);
    }
    else
    {
        CDialog::OnPaint();
    }
}

// The system calls this function to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CPizza_ProgramDlg::OnQueryDragIcon()
{
    return static_cast<HCURSOR>(m_hIcon);
}


void CPizza_ProgramDlg::OnEnChangeEditSummary()
{

    // TODO:  If this is a RICHEDIT control, the control will not
    // send this notification unless you override the CDialog::OnInitDialog()
    // function and call CRichEditCtrl().SetEventMask()
    // with the ENM_CHANGE flag ORed into the mask.

    // TODO:  Add your control notification handler code here
}

void CPizza_ProgramDlg::OnBnClickedOk()
{
    // TODO: Add your control notification handler code here
    OnOK();
}

void CPizza_ProgramDlg::OnBnClickedButtonProcess()
{
    // TODO: Add your control notification handler code here

    UpdateData(TRUE);
    m_Summary += "Customer's Name: ";
    m_Summary += m_Name;
    m_Summary += char(13);
    m_Summary += char(10);
    m_Summary += "Customer's Address: ";
    m_Summary += m_Address;
    m_Summary += char(13);
    m_Summary += char(10);
    m_Summary += "Customer's Phone Number: ";
    m_Summary += m_Phone;


   if (m_Small==TRUE)
{
    m_Summary += char(13);
    m_Summary += char(10);
    m_Summary += "Small Pizza $5.00";
}
   else if (m_Medium==TRUE)
{
    m_Summary += char(13);
    m_Summary += char(10);
    m_Summary += "Medium Pizza $10.00";
}
   else if (m_Large==TRUE)
   { 
       m_Summary += char(13);
       m_Summary += char(10);
       m_Summary += "Large Pizza $15.00";
   }

   if (m_Extra==TRUE)
   {
       m_Summary += char(13);
       m_Summary += char(10);
       m_Summary += "Extra Cheese +$1.00";
   }

      if (m_Pepperoni==TRUE)
   {
       m_Summary += char(13);
       m_Summary += char(10);
       m_Summary += "Pepperoni +$1.00";
   }

         if (m_Sausage==TRUE)
   {
       m_Summary += char(13);
       m_Summary += char(10);
       m_Summary += "Sausage +$1.00";
   }

        if (m_Peppers==TRUE)
   {
       m_Summary += char(13);
       m_Summary += char(10);
       m_Summary += "Peppers +$1.00";
   }

           if (m_Mushrooms==TRUE)
   {
       m_Summary += char(13);
       m_Summary += char(10);
       m_Summary += "Mushrooms +$1.00";
   }
              if (m_Onions==TRUE)
   {
       m_Summary += char(13);
       m_Summary += char(10);
       m_Summary += "Onions +$1.00";
   }

    UpdateData(FALSE);
}

Answer 1

您需要添加对 DDX_Radio 在类的 DoDataExchange 函数中。

为此，您应该将 m_Small、m_Medium 和 m_Large 成员变量替换为单个整数：

int m_Size;

假设第一个单选按钮的 ID是 IDC_SMALL，那么 DDX_Radio 调用将为：（

DDX_Radio(pDX, IDC_SMALL, m_Size);

不幸的是，您不能将 m_Size 声明为 enum因为 DDX_Radio 需要一个 int。）

此外，如 Aiden Ryan 正确指出，在 Visual Studio 资源编辑器中确保单选按钮按对话框选项卡顺序按顺序出现。 第一个单选按钮的 Group 属性应设置为 True，其他单选按钮的 Group 属性应设置为 False。

Answer 2

单选按钮往往用于具有两个以上值的变量，因此不要使用三个变量：

BOOL m_Small;
BOOL m_Medium;
BOOL m_Large;

您将拥有一个枚举：

enum PizzaSize {Small, Medium, Large};

和此类型的变量：

PizzaSize m_Size;

单选按钮将设置此变量。

然后你的代码将变成：

switch (m_Size)
{
    case Small:
        m_Summary += char(13);
        m_Summary += char(10);
        m_Summary += "Small Pizza $5.00";
        break;
    case Medium:
        m_Summary += char(13);
        m_Summary += char(10);
        m_Summary += "Medium Pizza $10.00";
    case Large:
        m_Summary += char(13);
        m_Summary += char(10);
        m_Summary += "Large Pizza $15.00";
}

自从我完成 C++ & 以来已经有一段时间了。 MFC 因此将其视为起点而不是最终代码；）

Answer 3

ChrisF的回答非常好，是在MFC中做单选按钮的正确方法。

一个非常重要的注意事项：确保单选按钮按照对话框选项卡顺序按枚举顺序排列。