学步园

// EasySize.h

/*
 * 说明：一个用于在MFC对话框程序改变大小时自动保持各控件相对位置的功能类。
 * 用法：1、定义一个成员变量 CEasySize m_cEasySize;
 *       2、在对话框程序的OnInitDialog方法中加入 m_cEasySize.OnInitDialog(this);
 *       3、在对话框程序的OnSize方法中加入 m_cEasySize.OnSize(cx, cy);
 */

#pragma once

#include <afxtempl.h>

struct ControlPos
{
	int nID;
	float fT;
	float fB;
	float fL;
	float fR;
};

class CEasySize
{
public:
	CEasySize();

public:
	void OnInitDialog(CDialog* pDlg);
	void OnInitDialog(HWND hWnd);
	void OnSize(int cx, int cy);

private:
	void RecordControlPos(int nID, CRect cClientRect);
	void AdjustControlPos(int nID, int cx, int cy);

private:
	BOOL m_Init;
	HWND m_hDlg;
	CList<ControlPos> m_listControlPos;
};

// EasySize.cpp

#include "stdafx.h"
#include "EasySize.h"

CEasySize::CEasySize()
{
    m_Init = FALSE;
    m_hDlg = NULL;
}

void CEasySize::OnInitDialog(CDialog* pDlg)
{
    OnInitDialog(pDlg->GetSafeHwnd());
}

void CEasySize::OnInitDialog(HWND hWnd)
{
    m_Init = TRUE;
    m_hDlg = hWnd;

    CRect cClientRect;
    GetClientRect(m_hDlg, &cClientRect);

    HWND hWndChild = GetWindow(m_hDlg, GW_CHILD);
    while ( hWndChild )
    {
        CWnd *pCWnd = CWnd::FromHandle(hWndChild);
        LONG nID = GetWindowLong(pCWnd->m_hWnd, GWL_ID);

        RecordControlPos(nID, cClientRect);

        hWndChild = GetWindow(hWndChild, GW_HWNDNEXT);
    }
}

void CEasySize::OnSize(int cx, int cy)
{
    if ( !m_Init )
    {
        return ;
    }

    HWND hWndChild = GetWindow(m_hDlg, GW_CHILD);
    while ( hWndChild )
    {
        CWnd* pCWnd = CWnd::FromHandle(hWndChild);
        LONG nID = GetWindowLong(pCWnd->m_hWnd, GWL_ID);

        AdjustControlPos(nID, cx, cy);

        hWndChild = GetWindow(hWndChild, GW_HWNDNEXT);
    }
}

void CEasySize::RecordControlPos(int nID, CRect cClientRect)
{
    CRect rect;
    GetWindowRect(GetDlgItem(m_hDlg, nID), &rect);
    ScreenToClient(m_hDlg, (LPPOINT)&rect);
    ScreenToClient(m_hDlg, ((LPPOINT)&rect)+1);

    ControlPos cControlPos;
    cControlPos.nID = nID;
    cControlPos.fT = float(rect.top) / float(cClientRect.Height());
    cControlPos.fB = float(rect.bottom) / float(cClientRect.Height());
    cControlPos.fL = float(rect.left) / float(cClientRect.Width());
    cControlPos.fR = float(rect.right) / float(cClientRect.Width());

    int nCount = (int)m_listControlPos.GetCount();
    if ( 0 == nCount )
    {
        m_listControlPos.AddTail(cControlPos);
        return ;
    }
    else
    {
        POSITION pos = m_listControlPos.GetHeadPosition();
        while ( nCount )
        {
            ControlPos cControlPosTmp = m_listControlPos.GetAt(pos);
            if ( cControlPosTmp.nID == nID )
            {
                return ;
            }
            m_listControlPos.GetNext(pos);
            --nCount;
        }

        m_listControlPos.AddTail(cControlPos);
    }
}

void CEasySize::AdjustControlPos(int nID, int cx, int cy)
{
    int nCount = (int)m_listControlPos.GetCount();

    POSITION pos = m_listControlPos.GetHeadPosition();
    while ( nCount )
    {
        ControlPos cControlPos;
        cControlPos = m_listControlPos.GetAt(pos);
        if ( cControlPos.nID == nID )
        {
            CRect rect;
            rect.top = LONG(cControlPos.fT * cy);
            rect.bottom = LONG(cControlPos.fB * cy);
            rect.left = LONG(cControlPos.fL * cx);
            rect.right = LONG(cControlPos.fR * cx);

            MoveWindow(
                GetDlgItem(m_hDlg, nID),
                rect.left,
                rect.top,
                rect.Width(),
                rect.Height(),
                TRUE);

            return ;
        }
        m_listControlPos.GetNext(pos);
        --nCount;
    }
}