使用GDI+ MeasureString方法计算显示 输入文本的长度

// stdafx.h : include file for standard system include files,
// or project specific include files that are used frequently, but
// are changed infrequently
//

#if !defined(AFX_STDAFX_H__660C12D0_6133_459C_B633_7A2DFC9FFD72__INCLUDED_)
#define AFX_STDAFX_H__660C12D0_6133_459C_B633_7A2DFC9FFD72__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#define VC_EXTRALEAN // Exclude rarely-used stuff from Windows headers

#ifndef ULONG_PTR
#define ULONG_PTR unsigned long*
#endif

#include <afxwin.h> // MFC core and standard components
#include <afxext.h> // MFC extensions
#include <afxdisp.h> // MFC Automation classes
#include <afxdtctl.h> // MFC support for Internet Explorer 4 Common Controls
#ifndef _AFX_NO_AFXCMN_SUPPORT
#include <afxcmn.h> // MFC support for Windows Common Controls
#endif // _AFX_NO_AFXCMN_SUPPORT

#include <GdiPlus.h>
using namespace Gdiplus;

#pragma comment(lib, "gdiplus.lib")

//{{AFX_INSERT_LOCATION}}
// Microsoft Visual C++ will insert additional declarations immediately before the previous line.

#endif // !defined(AFX_STDAFX_H__660C12D0_6133_459C_B633_7A2DFC9FFD72__INCLUDED_)

// MeasureStringTestDlg.h : header file
//

#if !defined(AFX_MEASURESTRINGTESTDLG_H__4887F642_8530_485A_8067_D30D1664AD2D__INCLUDED_)
#define AFX_MEASURESTRINGTESTDLG_H__4887F642_8530_485A_8067_D30D1664AD2D__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

/////////////////////////////////////////////////////////////////////////////
// CMeasureStringTestDlg dialog

class CMeasureStringTestDlg : public CDialog
{
// Construction
public:
CMeasureStringTestDlg(CWnd* pParent = NULL); // standard constructor

// Dialog Data
//{{AFX_DATA(CMeasureStringTestDlg)
enum { IDD = IDD_MEASURESTRINGTEST_DIALOG };
// NOTE: the ClassWizard will add data members here
//}}AFX_DATA

// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CMeasureStringTestDlg)
protected:
virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support
//}}AFX_VIRTUAL

// Implementation
protected:
HICON m_hIcon;

// Generated message map functions
//{{AFX_MSG(CMeasureStringTestDlg)
virtual BOOL OnInitDialog();
afx_msg void OnSysCommand(UINT nID, LPARAM lParam);
afx_msg void OnPaint();
afx_msg HCURSOR OnQueryDragIcon();
afx_msg void OnButton1();
afx_msg void OnChangeEdit1();
//}}AFX_MSG
DECLARE_MESSAGE_MAP()

public:
int GetShowIndex( CRect& rectEdit, wchar_t* pText, Font& font, StringFormat& sf);
};

//{{AFX_INSERT_LOCATION}}
// Microsoft Visual C++ will insert additional declarations immediately before the previous line.

#endif // !defined(AFX_MEASURESTRINGTESTDLG_H__4887F642_8530_485A_8067_D30D1664AD2D__INCLUDED_)

// MeasureStringTestDlg.cpp : implementation file
//

#include "stdafx.h"
#include "MeasureStringTest.h"
#include "MeasureStringTestDlg.h"
#include "GdiPlus.h"
#include "GdiPlusInit.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About

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

// Dialog Data
//{{AFX_DATA(CAboutDlg)
enum { IDD = IDD_ABOUTBOX };
//}}AFX_DATA

// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CAboutDlg)
protected:
virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support
//}}AFX_VIRTUAL

// Implementation
protected:
//{{AFX_MSG(CAboutDlg)
//}}AFX_MSG
DECLARE_MESSAGE_MAP()
};

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

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

BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
//{{AFX_MSG_MAP(CAboutDlg)
// No message handlers
//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMeasureStringTestDlg dialog

CMeasureStringTestDlg::CMeasureStringTestDlg(CWnd* pParent /*=NULL*/)
: CDialog(CMeasureStringTestDlg::IDD, pParent)
{
//{{AFX_DATA_INIT(CMeasureStringTestDlg)
// NOTE: the ClassWizard will add member initialization here
//}}AFX_DATA_INIT
// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CMeasureStringTestDlg::DoDataExchange(CDataExchange* pDX)
{
CDialog::DoDataExchange(pDX);
//{{AFX_DATA_MAP(CMeasureStringTestDlg)
// NOTE: the ClassWizard will add DDX and DDV calls here
//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CMeasureStringTestDlg, CDialog)
//{{AFX_MSG_MAP(CMeasureStringTestDlg)
ON_WM_SYSCOMMAND()
ON_WM_PAINT()
ON_WM_QUERYDRAGICON()
ON_BN_CLICKED(IDC_BUTTON1, OnButton1)
ON_EN_CHANGE(IDC_EDIT1, OnChangeEdit1)
//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMeasureStringTestDlg message handlers

BOOL CMeasureStringTestDlg::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

GdiplusStartupInput gdiplusStartupInput;
ULONG_PTR gdiplusToken;
GdiplusStartup( &gdiplusToken, &gdiplusStartupInput, NULL );

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

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

SendMessage(WM_ICONERASEBKGND, (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 to obtain the cursor to display while the user drags
// the minimized window.
HCURSOR CMeasureStringTestDlg::OnQueryDragIcon()
{
return (HCURSOR) m_hIcon;
}

void CMeasureStringTestDlg::OnButton1()
{
// TODO: Add your control notification handler code here
CString strText = "";
GetDlgItem(IDC_EDIT1)->GetWindowText( strText );

WCHAR m_awszFontName[64];
ZeroMemory( m_awszFontName, sizeof(m_awszFontName) );
const char* achFontFamlyName = ("Arial") ;
MultiByteToWideChar(CP_ACP, 0, achFontFamlyName, -1, m_awszFontName, strlen(achFontFamlyName) );

SolidBrush brush( Color( 255, 0, 0 ) );

FontFamily fontFamily( m_awszFontName );
Font font( &fontFamily, 14 );
Graphics graphics(m_hWnd);

CRect cRect;
GetDlgItem(IDC_STDRAW)->GetWindowRect( &cRect );

POINT point = cRect.TopLeft();

::ScreenToClient( m_hWnd, &point );

StringFormat sf;
sf.SetFormatFlags( StringFormatFlagsNoWrap | StringFormatFlagsMeasureTrailingSpaces );
sf.SetLineAlignment( StringAlignmentCenter ); //StringAlignmentNear StringAlignmentCenter
sf.SetAlignment( StringAlignmentFar );

WCHAR *pwszText = NULL;
pwszText = new WCHAR[strText.GetLength() + 1];
int nLen = MultiByteToWideChar( CP_ACP, 0, strText, -1, NULL, NULL );
MultiByteToWideChar(CP_ACP, 0, strText, -1, pwszText, nLen);
DWORD dwTextLen = wcslen(pwszText);
RectF rectString;
RectF rectStringBk;

graphics.MeasureString( pwszText/*L"a"*/, -1, &font, PointF( (float)0, (float)0 ), &sf, &rectString );
rectStringBk = rectString;

CString strRectStringWidth = "";
strRectStringWidth.Format("%f , %f ", rectString.Width, rectString.Height );
GetDlgItem(IDC_EDIT2)->SetWindowText(strRectStringWidth);

DWORD dwIndex = GetShowIndex( cRect, pwszText, font, sf );

graphics.DrawString(pwszText + dwTextLen - dwIndex+1, -1, &font, RectF( (float)point.x, (float)point.y,
cRect.Width(), cRect.Height()), &sf, &brush );

delete []pwszText;
pwszText = NULL;

}

int CMeasureStringTestDlg::GetShowIndex( CRect& rectEdit, wchar_t* pText, Font& font, StringFormat& sf)
{
if ( NULL == pText)
{
return 0;
}

DWORD dwTextLen = wcslen( pText );
DWORD dwIndex = 0;

Graphics graphics(m_hWnd);

RectF rectString;
rectString.Width = 0;

for( int i = dwTextLen; i>=0; i--)
{
if ( rectString.Width < (float)rectEdit.Width() )
{
dwIndex++;
graphics.MeasureString( pText + dwTextLen - dwIndex , -1, &font, PointF( (float)0, (float)0 ), &sf, &rectString );

if ( rectString.Width > (float)rectEdit.Width() )
{
//还是采用上一次的
dwIndex--;
break;
}
}
else
{
break;
}
}

return dwIndex;
}

void CMeasureStringTestDlg::OnChangeEdit1()
{
// 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
RedrawWindow();
OnButton1();
}