MFC对话框中的控件随着对话框大小变化而变化

转自：http://www.codeproject.com/Articles/1657/EasySize-Dialog-resizing-in-no-time

Download source files - 1.71 Kb

Download demo project - 13.9 Kb

Introduction

Have you ever thought of how annoying it actually was to spend a lot of time doing a basic GUI for your simple applications instead of focusing on the actual 'content'? Take for example a resizing dialog or property page. You need to write code for each
control that will tell it where to go when the thing is resized, and this can take up a lot of time. Now I know that I'm not the first one to give a solution to this (CResizableDialog),
but this article is on my approach.

Description

Basically, all you need to do is design your dialog the way you want it to look in the resource editor (don't forget to make it resizable), and then define how the controls will behave when the dialog is resized using one single macro for each control.

Usage

Note that all this works exactly the same way with both

CDialog

and

CPropertyPage

#include

EasySize.h to
your stdafx.h (or put it in your include directory and

#include

<EasySize.h> ,
which I recommend)
Add

DECLARE_EASYSIZE

anywhere
in your class declaration:


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Code

class CEasySizeDemoDlg : public CDialog
{
DECLARE_EASYSIZE
...

Create an

OnInitDialog

handler if it doesn't already exist, and put
this in the end of it: "

INIT_EASYSIZE;

"
:


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BOOL CEasySizeDemoDlg::OnInitDialog()
{
CDialog::OnInitDialog();
...
INIT_EASYSIZE;
return TRUE; // return TRUE  unless you set the focus to a control
}

Create an

OnSize

handler and add the

UPDATE_EASYSIZE;

macro
to it:


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void CEasySizeDemoDlg::OnSize(UINT nType, int cx, int cy)
{
CDialog::OnSize(nType, cx, cy);
UPDATE_EASYSIZE;
}

Optional - If you want your dialog to have a minimum size, then create an

OnSizing

handler
and add the

EASYSIZE_MINSIZE

macro
as below:


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void CEasySizeDemoDlg::OnSizing(UINT fwSide, LPRECT pRect)
{
CDialog::OnSizing(fwSide, pRect);
EASYSIZE_MINSIZE(280,250,fwSide,pRect);
}
//(in this example, 280 is the minimum width and 250 the
//minimum height we want our dialog to have)

Now you have to create the "EasySize Map"
(or whatever you want to call it) in which you will specify the behavior of each dialog item. It can be placed anywhere inside your class implementation. The map looks like this:


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Code

BEGIN_EASYSIZE_MAP(class_name)
...
EASYSIZE(control,left,top,right,bottom,options)
...
END_EASYSIZE_MAP

The map from the demo application looks like this:


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...
//}}AFX_MSG_MAP
END_MESSAGE_MAP()

BEGIN_EASYSIZE_MAP(CEasySizeDemoDlg)
EASYSIZE(IDC_TITLE,ES_BORDER,ES_BORDER,
ES_BORDER,ES_KEEPSIZE,ES_HCENTER)
EASYSIZE(IDC_RADIO1,ES_BORDER,ES_BORDER,
ES_KEEPSIZE,ES_KEEPSIZE,0)
EASYSIZE(IDC_RADIO2,ES_BORDER,ES_BORDER,
ES_KEEPSIZE,ES_KEEPSIZE,0)
EASYSIZE(IDC_CONTENT,ES_BORDER,ES_BORDER,
ES_BORDER,ES_BORDER,0)
EASYSIZE(IDC_STATUSFRAME,ES_BORDER,ES_KEEPSIZE,
ES_BORDER,ES_BORDER,0)
EASYSIZE(IDC_STATUS,ES_BORDER,ES_KEEPSIZE,
ES_BORDER,ES_BORDER,0)
EASYSIZE(IDOK,ES_KEEPSIZE,ES_KEEPSIZE,
ES_BORDER,ES_BORDER,0)
EASYSIZE(IDCANCEL,ES_KEEPSIZE,ES_KEEPSIZE,
ES_BORDER,ES_BORDER,0)
EASYSIZE(IDC_MYICON1,ES_BORDER,IDC_RADIO2,IDC_CONTENT,
IDC_STATUSFRAME,ES_HCENTER|ES_VCENTER)
EASYSIZE(IDC_MYICON2,ES_BORDER,ES_BORDER,IDC_TITLE,
ES_KEEPSIZE,ES_HCENTER)
END_EASYSIZE_MAP

///////////////////////////////////////////////////////////////
// CEasySizeDemoDlg message handlers
...

Looks confusing? It's not once you get the point (and I know I'm not good at explaining it) Read on.

EASYSIZE Macro

The

EASYSIZE

macro
is used in the EasySize Map to specify what behavior your controls will have on
dialog resize. It looks like this:


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Code

EASYSIZE(control,left,top,right,bottom,options)

control

is the ID of the dialog item you want re-positioned (which will be referred to as the 'current control'
further on).

left, top, right and bottom

can be either the ID of another control in the dialog (not the current control), or
one of the special values,

ES_BORDER

and

ES_KEEPSIZE

.

Basically, if you specify an ID, the distance from the current control and the item designated by the ID will remain the same when the dialog is resized: The current control will 'stick' to the other item.

ES_BORDER

works
the same way as if you had specified a control ID, except that it's the distance between the current control and the dialog border that will be kept constant. Specifying

ES_KEEPSIZE

in,
let's say

left

, will keep the width of the current control the same, and will make the current control right-aligned
to whatever you specified in

right

. The width (or height, if you specified

ES_KEEPSIZE

in

top

or

bottom

)
of the current control will always remain what it is in the dialog resource. (I know this explanation sucks, but look at the demo application if you are confused or post you question in the board below). Obviously

ES_KEEPSIZE

cannot
be specified in both

"left

and

right"

or

"top

and

bottom"

.

options

can be a combination of

ES_HCENTER

,

ES_VCENTER

and
0 (use 0 if you don't want any of the other).

ES_HCENTER

horizontally centers the control between the two items specified
in

left

and

right

(both
of those can not be

ES_KEEPSIZE

!). The width of the current control will always remain the same as in the dialog resource.

ES_VCENTER

works
the same way, but for vertical centering (using

top

and

bottom

,
and where the height will remain constant).

Conclusion

Well I hope you figured out how this works, because it really can make your life easier. Note that using these macros will probably make your compiled code slightly bigger and slower than if you had coded the resizing routines manually, but in most cases
the change is so small not even you will notice.

Last Update - Just corrected a few typos.

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here

About the Author

Marc
Richarme

Engineer Nokia

Denmark


My programming experience started a long time ago in

QBasic (on a 25MHz 486).

I'm now mainly using Java, C++, C, MFC, Perl and PHP, but have used quite a number of other languages as well for various projects.