【在窗口上写字】

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在窗口上写字

以前写过一个类似的：http://dev.csdn.net/develop/article/29/29193.shtm

不过没有处理好back space等问题。而且显示字体也收到限制。这个依然是个不成熟的，不过可以改进。

类代码：

==============================================================

---TextFun.h---

/************************************************************

* Note:

* A class of drawing font on any window witch was attached to

* an instance of this class.

* Bugs to fit:

* 1, No memory dc supported so that XORPEN maybe disturb the

* existing font shape on dc.

* 2, The class cannot serialize the drawing opts.

* 3, On small font, the urgly face to be improved.

* By enoloo

* First edition ： 8/10,2004

************************************************************/

#ifndef _TextFun_H_

#define _TextFun_H_

#include <string>

#include <tchar.h>

#include <windows.h>

#include <assert.h>

class CTextFun

{

public:

CTextFun(){}

CTextFun(HWND hWnd,HFONT hFont = NULL,

COLORREF color = RGB(0,0,255));

~CTextFun();

public:

void Attach(HWND hWnd,HFONT hFont = NULL,

COLORREF color = RGB(0,0,255));

void Enter(POINT point);

void Leave();

bool IsAttached() const { return (m_hWnd != NULL && ::IsWindow(m_hWnd)); }

public:

bool PushChar(UINT nChar,bool bForward);

void PopChar();

void PushString(LPCTSTR str2Push);

std::string GetString() const { return m_strText; }

long GetHeight() const { return m_nHeight; }

long GetWidth() const { return (m_ptNow.x - m_ptStart.x); }

POINT GetCurrentPoint() const { return m_ptNow; }

protected:

// create a default TRUE-TYPE font here.

void CreateDefaultFont();

void _PushString(LPCTSTR str2Push,bool bForward);

protected:

HWND m_hWnd;

HFONT m_hFont;

std::string m_strText;

POINT m_ptStart;

POINT m_ptNow;

COLORREF m_clColor;

long m_nHeight;

bool m_bDefaultFont;

};

#endif

========================================================

---TextFun.cpp---

#include "TextFun.h"

CTextFun::CTextFun(HWND hWnd, HFONT hFont /* = NULL */,

COLORREF color /* = RGB */)

{

Attach(hWnd,hFont,color);

}

CTextFun::~CTextFun()

{

if(m_bDefaultFont)

::DeleteObject(m_hFont);

Leave();

}

// NOTE: hFont must be a true type font.

void CTextFun::Attach(HWND hWnd,HFONT hFont /* = NULL */, COLORREF color /* = RGB */)

{

assert(hWnd);

assert(::IsWindow(hWnd));

m_hWnd = hWnd;

HDC hdc = NULL;

hdc = ::GetDC(hWnd);

assert(hdc);

if(hFont == NULL)

{

m_bDefaultFont = true;

HFONT hft = (HFONT)::GetCurrentObject(hdc, OBJ_FONT);

assert(hft);

m_hFont = hft;

CreateDefaultFont();

}

else

{

m_bDefaultFont = false;

m_hFont = hFont;

}

m_clColor = color; //color;

HFONT oldFt = (HFONT)::SelectObject(hdc,m_hFont);

TEXTMETRIC tm;

::GetTextMetrics(hdc, &tm);

m_nHeight = tm.tmHeight;

::SelectObject(hdc,oldFt);

::ReleaseDC(hWnd,hdc);

}

void CTextFun::Enter(POINT point)

{

m_ptStart = m_ptNow = point;

::DestroyCaret();

assert( ::CreateCaret(m_hWnd, NULL, 1, m_nHeight) );

::ShowCaret(m_hWnd);

::SetCaretPos(point.x, point.y);

}

void CTextFun::Leave()

{

m_ptStart.x = m_ptNow.x = m_ptStart.y = m_ptNow.y = 0;

m_strText.erase();

::HideCaret(m_hWnd);

::DestroyCaret();

}

// for OnChar...

bool CTextFun::PushChar(UINT nChar,bool bForward)

{

static bool bFirstChinese = false;

static char strTemp[3];

if(nChar > 127 && !bFirstChinese) // maybe a chinese char code

{

if(bForward)

strTemp[0] = nChar;

else

strTemp[1] = nChar;

bFirstChinese = true;

return false; // wait for the second char code

}

else if(nChar > 127 && bFirstChinese)

{

if(bForward)

strTemp[1] = nChar;

else

strTemp[0] = nChar;

strTemp[2] = 0;

bFirstChinese = false;

}

else // an ascii char code

{

bFirstChinese = false; // back the status here.

strTemp[0] = nChar;

strTemp[1] = 0;

}

_PushString(strTemp,bForward);

return true;

}

void CTextFun::PopChar()

{

int strLength = m_strText.length();

if(m_strText.empty())

return;

HDC hdc = NULL;

hdc = ::GetDC(m_hWnd);

assert(hdc);

if(!PushChar( m_strText[strLength - 1], false )) // maybe a chinese char code

{

if(m_strText.empty())

{

m_strText.erase();

return;

}

PushChar( m_strText[strLength - 2], false );

}

return;

}

void CTextFun::_PushString(LPCTSTR str2Push,bool bForward)

{

// Create a caret always.

int strLen = _tcsclen(str2Push);

assert (strLen >= 0);

assert( ::CreateCaret(m_hWnd, NULL, 1, m_nHeight) );

::ShowCaret(m_hWnd);

HDC hdc = NULL;

hdc = ::GetDC(m_hWnd);

assert(hdc);

int preX = m_ptNow.x; // save it.

LOGBRUSH logBr;

logBr.lbColor = m_clColor;

logBr.lbHatch = 0;

logBr.lbStyle = BS_SOLID;

HPEN pen,oldPen;

pen = (HPEN)::ExtCreatePen( PS_GEOMETRIC | PS_SOLID |

PS_ENDCAP_SQUARE | PS_JOIN_BEVEL, 1, &logBr, 0, NULL);

// pen = (HPEN)::CreatePen(PS_SOLID,1,m_clColor);

oldPen = (HPEN)::SelectObject(hdc, (HGDIOBJ)pen);

HBRUSH br,oldBr;

br = ::CreateSolidBrush(m_clColor);

oldBr = (HBRUSH)::SelectObject(hdc, (HGDIOBJ)br);

HFONT oldFt = (HFONT)::SelectObject(hdc,m_hFont);

RECT rtQuery;

::DrawText(hdc, str2Push, _tcslen(str2Push), &rtQuery, DT_CALCRECT); // get the RECT for the char to draw

HRGN hRgn;

if(bForward)

{

m_ptNow.x = m_ptNow.x + (rtQuery.right - rtQuery.left);

hRgn = ::CreateRectRgn(preX, m_ptNow.y, m_ptNow.x, m_ptNow.y + m_nHeight);

}

else

{

m_ptNow.x = m_ptNow.x - (rtQuery.right - rtQuery.left);

hRgn = ::CreateRectRgn(m_ptNow.x, m_ptNow.y, preX, m_ptNow.y + m_nHeight);

}

// ::ExtSelectClipRgn(hdc,hRgn,RGN_COPY);

// set the caret's pos now

::SetCaretPos(m_ptNow.x, m_ptNow.y);

::SetBkMode(hdc,TRANSPARENT);

// draw the char code

// ::SetPolyFillMode(hdc,ALTERNATE);

int preR2 = ::SetROP2(hdc,R2_NOTXORPEN);

::BeginPath(hdc);

if(bForward)

::TextOut(hdc, preX, m_ptNow.y, str2Push , _tcslen(str2Push));

else

::TextOut(hdc, m_ptNow.x, m_ptNow.y, str2Push, _tcslen(str2Push));

::EndPath(hdc);

// NOTE: DONT call a silly function StrokeAndFillPath!

::StrokeAndFillPath(hdc);

// ::SelectClipPath(hdc,RGN_AND);

::SetROP2(hdc,preR2);

::SelectObject(hdc, (HGDIOBJ)oldPen);

::SelectObject(hdc, (HGDIOBJ)oldBr);

::SelectObject(hdc, (HGDIOBJ)oldFt);

// save the char code

if(bForward)

m_strText += std::string(str2Push);

else

m_strText = m_strText.substr(0, m_strText.length() - _tcslen(str2Push));

return;

}

void CTextFun::PushString(LPCTSTR str2Push)

{

_PushString(str2Push,true);

}

void CTextFun::CreateDefaultFont()

{

LOGFONT lf;

::memset(&lf,0,sizeof(LOGFONT));

lf.lfHeight = 40;

lf.lfWeight = /*FW_BOLD*/ FW_NORMAL;

lf.lfEscapement = 0;

lf.lfOrientation = 0;

lf.lfItalic = FALSE;

lf.lfUnderline = FALSE;

lf.lfStrikeOut = FALSE;

lf.lfCharSet = ANSI_CHARSET;

lf.lfOutPrecision = OUT_DEFAULT_PRECIS;

lf.lfClipPrecision = DRAFT_QUALITY;

lf.lfPitchAndFamily = VARIABLE_PITCH | FF_MODERN;

strcpy(lf.lfFaceName, "Arial");

m_hFont = ::CreateFontIndirect(&lf);

}

说明：

类支持在一个和类对象绑定(Attach)的窗口上写字，支持所有true-type字体。支持bake escape键。如果换行，可以从类中得到高度，在下面创建一个新的类对象就可以了。

不支持上下左右光标，没有memdc的支持，因为是用NotXorPen和路径作出来的，所以文字会在叠加的时候产生干扰。解决这些问题应该不是很困难。

使用：

1，将窗体和CTextFun对象绑定。绑定中可以指定true-type字体和颜色。也可以使用默认的。m_fun为一个CTextFun对象，调用：

m_fun.Attach(this->GetSafeHwnd());

2，显示文字可以调用Enter和Leave来完成。Enter函数设置显示光标的位置，Leave函数清空保存的缓冲文字数据。如果在视图中，可以在OnLButtonDown中调用：

m_fun.Enter(point);

在OnChar中，可以这么调用：

void CChildView::OnChar(UINT nChar, UINT nRepCnt, UINT nFlags)

{

// TODO: Add your message handler code here and/or call default

if(nChar == VK_BACK) // back键就退格，和文本框一样

{

m_fun.PopChar();

CWnd::OnChar(nChar,nRepCnt,nFlags);

return;

}

else if(nChar == VK_RETURN) // 回车键，结束显示

{

m_fun.Leave();

CWnd::OnChar(nChar,nRepCnt,nFlags);

return;

}

m_fun.PushChar(nChar,true); // 普通键，再绑定的窗口上显示

CWnd ::OnChar(nChar, nRepCnt, nFlags);

}

3，上面在OnChar中同步显示字符，如果要一次显示一个串呢，可以调用：

m_fun.PushString("中国"); // 比如在OnLButtonDown中调用

效果如下：

测试代码等找到免费空间之后传上来的J。

By enoloo,

8/10,2004