mfc对话框窗口最大化及拉伸缩放的实现
参考资料：https://blog.csdn.net/shufac/article/details/25563027
MFC对话框控件和背景图片自适应窗口最大化和拉伸缩放的实现
假设创建的对话框的类名是CMyDlg，具体过程如下：
步骤一：把easysize.h拷贝到CMyDlg项目文件夹中，同时在CMyDlg的.h文件和.cpp文件中加入#include"easysize.h"；
or（#include EasySize.h to your stdafx.h (or put it in your include directory and #include <EasySize.h> , which I recommend)
步骤二：在CMyDlg类的h文件中，加入DECLARE_EASYSIZE，注意结尾处不要加“；”。
class CMyDlg : public CDialog
{
DECLARE_EASYSIZE
// Construction
…
}
步骤三：在CMyDlg类的OnInitDialog()函数的结尾处加入INIT_EASYSIZE, 注意此处结尾处要加“；”。
BOOL CMyDlg::OnInitDialog()
{ …
// TODO: Add extra initialization here
INIT_EASYSIZE;
return TRUE; // return TRUE unless you set the focus to a control
}
步骤四：增加WM_SIZE消息响应函数OnSize()，在函数中加入UPDATE_EASYSIZE，注意此处结尾处要加“；”。
void CMyDlg::OnSize(UINT nType, int cx, int cy)
{
CDialog::OnSize(nType, cx, cy);
// TODO: Add your message handler code here
UPDATE_EASYSIZE;
}
OnSizing(）函数中可以设置窗口最小尺寸
void CchinaDiankeSarDisPlayImagDlg::OnSizing(UINT fwSide, LPRECT pRect)
{
CDialogEx::OnSizing(fwSide, pRect);
// TODO: 在此处添加消息处理程序代码
EASYSIZE_MINSIZE(587, 406, fwSide, pRect);
}
步骤五：在CMyDlg的cpp文件中添加EASYSIZE 的宏映射
BEGIN_EASYSIZE_MAP(CMyDlg)
EASYSIZE(control,left,top,right,bottom,options)
END_EASYSIZE_MAP
注意：如果没有添加EASYSIZE 的宏映射就开始编译的话，会出现链接错误！
这里需要解释的是宏EASYSIZE()的用法，其原型如下：
EASYSIZE(control,left,top,right,bottom,options)
该宏表示对ID值为control的控件实施缩放效果，缩放后的上下左右位置由control,left,top,right,bottom来确定，大小由option确定。
其中：control为对话框中的控件ID值，left,top,right,bottom四个参数为控件位置的坐标，其值可以选择ES_BOARD,ES_KEEPSIZE, 控件ID值三者之一。Options可以为ES_HCENTER, ES_VCENTER的结合，options可置0。
ES_BOARD表示控件与对话框边界（以下简称边界）的距离；
ES_KEEPSIZE表示控件水平/垂直方向上尺寸保持不变；
控件ID值表示当前控件与指定控件之间的距离；
ES_HCENTER表示缩放后控件在指定位置内水平居中；
ES_VCENTER表示缩放后控件在指定位置内垂直居中；
例如：
EASYSIZE(IDOK,ES_BORDER,ES_BORDER,ES_BORDER,ES_BORDER,0)
表示缩放后，值为IDOK的控件，距离边界上下左右位置保持不变，水平和垂直方向尺寸拉伸；
EASYSIZE(IDOK,ES_BORDER,ES_BORDER,ES_BORDER,ES_BORDER,ES_HCENTER)
表示缩放后，值为IDOK的控件，距离边界上下位置保持不变，垂直方向尺寸拉伸，水平居中；
EASYSIZE(IDOK,ES_BORDER,ES_BORDER,ES_BORDER,ES_BORDER,ES_HCENTER| ES_HCENTER)
表示缩放后，值为IDOK的控件，在对话框内垂直居中，水平居中；
EASYSIZE(IDOK,ES_BORDER,ES_KEEPSIZE,ES_KEEPSIZE,ES_BORDER,0)
表示缩放后，值为IDOK的控件，距离边界左、下方位置保持不变，同时保持控件尺寸；
EASYSIZE(IDOK,ES_BORDER,ES_KEEPSIZE, ES_BORDER,ES_BORDER,0)
表示缩放后，值为IDOK的控件，距离边界左、右、下方位置保持不变，水平方向尺寸拉伸，垂直方向尺寸不变；
EASYSIZE(IDOK,ES_BORDER,ES_BORDER,IDCANCEL,ES_BORDER,0)
表示缩放后，值为IDOK的控件，距离边界上下左位置保持不变，距离ID值为IDCANCEL的右方位置距离保持不变，水平和垂直方向尺寸拉伸；（当使用指定控件作为定位参数时候，确保指定控件的EASYSIZE在该宏前面）
easysize.h内容如下：
/*************************以下是EasySize.h源文*************************/
/*====================================================
EasySize.h |
| |
| EASY-SIZE Macros |
| |
| Copyright (c) 2001 - Marc Richarme |
| devix@devix.cjb.net |
| http://devix.cjb.net |
| |
| License: |
| |
| You may use this code in any commersial or non- |
| commersial application, and you may redistribute |
| this file (and even modify it if you wish) as |
| long as you keep this notice untouched in any |
| version you redistribute. |
| |
| Usage: |
| |
| - Insert 'DECLARE_EASYSIZE' somewhere in your |
| class declaration |
| - Insert an easysize map in the beginning of your |
| class implementation (see documentation) and |
| outside of any function. |
| - Insert 'INIT_EASYSIZE;' in your |
| OnInitDialog handler. |
| - Insert 'UPDATE_EASYSIZE' in your OnSize handler |
| - Optional: Insert 'EASYSIZE_MINSIZE(mx,my);' in |
| your OnSizing handler if you want to specify |
| a minimum size for your dialog |
| |
| Check http://devix.cjb.net for the |
| docs and new versions |
| |
=====================================================*/
#ifndef __EASYSIZE_H_
#define __EASYSIZE_H_
#define ES_BORDER 0xffffffff
#define ES_KEEPSIZE 0xfffffffe
#define ES_HCENTER 0x00000001
#define ES_VCENTER 0x00000002
#define DECLARE_EASYSIZE \
void __ES__RepositionControls(BOOL bInit); \
void __ES__CalcBottomRight(CWnd *pThis, BOOL bBottom, int &bottomright, int &topleft, UINT id, UINT br, int es_br, CRect &rect, int clientbottomright);
#define INIT_EASYSIZE __ES__RepositionControls(TRUE); __ES__RepositionControls(FALSE)
#define UPDATE_EASYSIZE if(GetWindow(GW_CHILD)!=NULL) __ES__RepositionControls(FALSE)
#define EASYSIZE_MINSIZE(mx,my,s,r) if(r->right-r->left < mx) { if((s == WMSZ_BOTTOMLEFT)||(s == WMSZ_LEFT)||(s == WMSZ_TOPLEFT)) r->left = r->right-mx; else r->right = r->left+mx; } if(r->bottom-r->top < my) { if((s == WMSZ_TOP)||(s == WMSZ_TOPLEFT)||(s == WMSZ_TOPRIGHT)) r->top = r->bottom-my; else r->bottom = r->top+my; }
#define BEGIN_EASYSIZE_MAP(class) \
void class::__ES__CalcBottomRight(CWnd *pThis, BOOL bBottom, int &bottomright, int &topleft, UINT id, UINT br, int es_br, CRect &rect, int clientbottomright) {\
if(br==ES_BORDER) bottomright = clientbottomright-es_br;\
else if(br==ES_KEEPSIZE) bottomright = topleft+es_br;\
else { CRect rect2;\
pThis->GetDlgItem(br)->GetWindowRect(rect2); pThis->ScreenToClient(rect2);\
bottomright = (bBottom?rect2.top:rect2.left) - es_br;}}\
void class::__ES__RepositionControls(BOOL bInit) { CRect rect,rect2,client; GetClientRect(client);
#define END_EASYSIZE_MAP Invalidate(); UpdateWindow(); }
#define EASYSIZE(id,l,t,r,b,o) \
static int id##_es_l, id##_es_t, id##_es_r, id##_es_b;\
if(bInit) {\
GetDlgItem(id)->GetWindowRect(rect); ScreenToClient(rect);\
if(o & ES_HCENTER) id##_es_l = rect.Width()/2; else {\
if(l==ES_BORDER) id##_es_l = rect.left; else if(l==ES_KEEPSIZE) id##_es_l = rect.Width(); else {\
GetDlgItem(l)->GetWindowRect(rect2); ScreenToClient(rect2);\
id##_es_l = rect.left-rect2.right;}}\
if(o & ES_VCENTER) id##_es_t = rect.Height()/2; else {\
if(t==ES_BORDER) id##_es_t = rect.top; else if(t==ES_KEEPSIZE) id##_es_t = rect.Height(); else {\
GetDlgItem(t)->GetWindowRect(rect2); ScreenToClient(rect2);\
id##_es_t = rect.top-rect2.bottom;}}\
if(o & ES_HCENTER) id##_es_r = rect.Width(); else { if(r==ES_BORDER) id##_es_r = client.right-rect.right; else if(r==ES_KEEPSIZE) id##_es_r = rect.Width(); else {\
GetDlgItem(r)->GetWindowRect(rect2); ScreenToClient(rect2);\
id##_es_r = rect2.left-rect.right;}}\
if(o & ES_VCENTER) id##_es_b = rect.Height(); else { if(b==ES_BORDER) id##_es_b = client.bottom-rect.bottom; else if(b==ES_KEEPSIZE) id##_es_b = rect.Height(); else {\
GetDlgItem(b)->GetWindowRect(rect2); ScreenToClient(rect2);\
id##_es_b = rect2.top-rect.bottom;}}\
} else {\
int left,top,right,bottom; BOOL bR = FALSE,bB = FALSE;\
if(o & ES_HCENTER) { int _a,_b;\
if(l==ES_BORDER) _a = client.left; else { GetDlgItem(l)->GetWindowRect(rect2); ScreenToClient(rect2); _a = rect2.right; }\
if(r==ES_BORDER) _b = client.right; else { GetDlgItem(r)->GetWindowRect(rect2); ScreenToClient(rect2); _b = rect2.left; }\
left = _a+((_b-_a)/2-id##_es_l); right = left + id##_es_r;} else {\
if(l==ES_BORDER) left = id##_es_l;\
else if(l==ES_KEEPSIZE) { __ES__CalcBottomRight(this,FALSE,right,left,id,r,id##_es_r,rect,client.right); left = right-id##_es_l;\
} else { GetDlgItem(l)->GetWindowRect(rect2); ScreenToClient(rect2); left = rect2.right + id##_es_l; }\
if(l != ES_KEEPSIZE) __ES__CalcBottomRight(this,FALSE,right,left,id,r,id##_es_r,rect,client.right);}\
if(o & ES_VCENTER) { int _a,_b;\
if(t==ES_BORDER) _a = client.top; else { GetDlgItem(t)->GetWindowRect(rect2); ScreenToClient(rect2); _a = rect2.bottom; }\
if(b==ES_BORDER) _b = client.bottom; else { GetDlgItem(b)->GetWindowRect(rect2); ScreenToClient(rect2); _b = rect2.top; }\
top = _a+((_b-_a)/2-id##_es_t); bottom = top + id##_es_b;} else {\
if(t==ES_BORDER) top = id##_es_t;\
else if(t==ES_KEEPSIZE) { __ES__CalcBottomRight(this,TRUE,bottom,top,id,b,id##_es_b,rect,client.bottom); top = bottom-id##_es_t;\
} else { GetDlgItem(t)->GetWindowRect(rect2); ScreenToClient(rect2); top = rect2.bottom + id##_es_t; }\
if(t != ES_KEEPSIZE) __ES__CalcBottomRight(this,TRUE,bottom,top,id,b,id##_es_b,rect,client.bottom);}\
GetDlgItem(id)->MoveWindow(left,top,right-left,bottom-top,FALSE);\
}
#endif //__EASYSIZE_H_
