MFC使用rich edit若干问题

鸣谢：https://www.xuebuyuan.com/599248.html

一般性问题

1.   
代码编译通过了，运行后RichEdit控件不显示，在InitInstance中添加

BOOL CWinApp::InitInstance ()

{

…

AfxInitRichEdit(); - RichEdit 1.0

或 AfxInitRichEdit2(); - RichEdit 2.0

…

}

 

2.   
升级默认的RichEdit版本，默认的版本有BUG，在InitInstance中添加

BOOL CWinApp::InitInstance ()

{

…

LoadLibrary("RICHED20.DLL");

…

FreeLibrary();

}

 

如果是CRichEditView基类的话，可用如下消息机制:

BOOL CRichEditView::PreCreateWindow(CREATESTRUCT& cs)

{

if (LoadLibraryA("RICHED20.DLL") == NULL)

{

AfxMessageBox(_T("Fail to load /"riched20.dll/"."),MB_OK | MB_ICONERROR);

PostMessage(WM_QUIT,0,0);
return FALSE;

}

 

m_strClass = RICHEDIT_CLASSA;

return CRichEditView::PreCreateWindow(cs);
}

 

3.   
在RichEdit控件的输入框中最后追加一行

CRichEditCtrl.SetSel(-1, -1);
CRichEditCtrl.ReplaceSel((LPCTSTR)str);

 

4.   
限制RichEdit控件的字数

CRichEditCtrl.LimitText(long nChars)

 

5.   
设置RichEdit控件的换行切换

如果是CRichEditView基类的话，可用如下消息机制:

BOOL CRichEditView::OnInitialUpdate()

{

…

m_nWordWrap = WrapNone;

WrapChanged();

…

}

 

如果是在Dialog，可使用SetTargetDevice，并在RichEdit的属性里面加上want
return

CRichEditCtrl.SetTargetDevice(m_dcTarget, GetPrintWidth());

 

WrapChanged实际上也是调用

CRichEditCtrl.SetTargetDevice(NULL, 0); //m_nWordWrap == WrapToWindow

CRichEditCtrl.SetTargetDevice(NULL, 1); //m_nWordWrap == WrapNone

CRichEditCtrl.SetTargetDevice(NULL, 2);// m_nWordWrap == WrapToTargetDevice

 

6.   
设置RichEdit控件不带格式的数据粘贴

CRichEditCtrl.PasteSpecial(CF_TEXT);

 

7.   
设置RichEdit控件的滚动条自动随输入滚动到最后一行

int nFirstVisible = CRichEditCtrl.GetFirstVisibleLine();

if (nFirstVisible > 0)
{

CRichEditCtrl.LineScroll(-nFirstVisible, 0);

}

或CRichEditCtrl.PostMessage(WM_VSCROLL, SB_BOTTOM, 0);

8.设置RichEdit控件的撤销输入次数(只能用在RICHED20以上)

SendMessage(EM_SETTEXTMODE, TM_MULTILEVELUNDO, 0);

SendMessage(EM_SETUNDOLIMIT, 100, 0);

TM_MULTILEVELUNDO 支持多取消(默认值)，可通过EM_SETUNDOLIMIT设置最大次数

 

9.设置RichEdit控件的OnChange事件

EM_SETEVENTMASK 设置 ENM_CHANGE

long lMask = GetEventMask();

lMask |= ENM_CHANGE;

lMask &= ~ENM_PROTECTED;

SetEventMask(lMask);

 

10.设置RichEdit控件的只读属性

CRichEditCtrl::SetReadOnly(BOOL bReadOnly = TRUE );

通过设置PROTECTED实现选中的文本只读，参见如下文章：

http://www.codeguru.com/Cpp/controls/richedit/article.php/c2401/

 

 

函数应用

1. 设置RichEdit控件的显示字体

CHARFORMAT cf;

ZeroMemory(&cf, sizeof(CHARFORMAT));

cf.cbSize = sizeof(CHARFORMAT);

cf.dwMask|=CFM_BOLD;

cf.dwEffects|=CFE_BOLD; //粗体，取消用cf.dwEffects&=~CFE_BOLD;

cf.dwMask|=CFM_ITALIC;

cf.dwEffects|=CFE_ITALIC; //斜体，取消用cf.dwEffects&=~CFE_ITALIC;

cf.dwMask|=CFM_UNDERLINE;

cf.dwEffects|=CFE_UNDERLINE; //斜体，取消用cf.dwEffects&=~CFE_UNDERLINE;
cf.dwMask|=CFM_COLOR;

cf.crTextColor = RGB(255,0,0); //设置颜色

cf.dwMask|=CFM_SIZE;

cf.yHeight =200; //设置高度

cf.dwMask|=CFM_FACE;

strcpy(cf.szFaceName ,_T("隶书")); //设置字体

CRichEditCtrl.SetSelectionCharFormat(cf);

 

2.设置RichEdit控件的显示字体的行间距（只能用在RICHED20以上）

PARAFORMAT2 pf;

pf.cbSize = sizeof(PARAFORMAT2);

pf.dwMask = PFM_NUMBERING | PFM_OFFSET;

pf.wNumbering = PFN_BULLET; //注意PFM_NUMBERING

pf.dxOffset = 10;

VERIFY(SetParaFormat(pf));

 

常用的dwMask有如下列表：

PFM_NUMBERING 成员 wNumbering
才起作用

1 项目符号，默认用PFN_BULLET.

2 使用阿拉伯数字 (1, 2, 3, ...).

3 使用小写字母 (a, b, c, ...).

4 使用大写字母 (A, B, C, ...).

5 使用小写罗马数字 (i, ii, iii, ...).

6 使用大写罗马数字 (I, II, III, ...).

7 自定义，字符见成员 wNumberingStart.

PFM_OFFSET 成员 dxOffset
才起作用，缩进，单位twips

PFM_STARTINDENT 成员 dxStartIndent
才起作用，首行缩进

PFM_SPACEAFTER 成员 dySpaceAfter
才起作用，段间距

PFM_LINESPACING 成员 dyLineSpacing
才起作用，行间距

 

3.设置RichEdit控件的透明背景（只能用在RICHED20以上）

long style = ::GetWindowLong(GetSafeHwnd(), GWL_EXSTYLE);

style &= WS_EX_TRANSPARENT;

::SetWindowLong(GetSafeHwnd(), GWL_EXSTYLE, style);

或 CreateEx()，然后把WS_EX_TRANSPARENT样式加上

 

4.获取或者写入RichEdit控件的内容

Ø        
GetWindowText

Ø        
使用EM_GETTEXTEX

GETTEXTEX gt;

gt.cb = 200;

gt.flags = GT_DEFAULT;

gt.codepage = CP_ACP ;

gt.lpDefaultChar = NULL;

gt.lpUsedDefChar = NULL;

SendMessage(EM_GETTEXTEX,(WPARAM)>,(LPARAM)text);

Ø        
StreamOut(主要用于RTF等格式输出)

static DWORD CALLBACK；

MyStreamOutCallback(DWORD dwCookie, LPBYTE pbBuff, LONG cb, LONG *pcb)

{

CFile* pFile = (CFile*) dwCookie;

pFile->Write(pbBuff, cb);

*pcb = cb;

return 0;
}

CFile cFile(TEXT("myfile.rtf"), CFile::modeCreate|CFile::modeWrite);

EDITSTREAM es;

es.dwCookie = (DWORD) &cFile; //设置用例参数,以便回调函数调用

es.pfnCallback = MyStreamOutCallback;

pmyRichEditCtrl->StreamOut(SF_RTF, es);

 

读入可以此类推，SetWindowText, EM_SETTEXTEX, StreamIn

 

5.查找RichEdit控件中的字符串

FINDTEXTEX ft;

ft.chrg.cpMin = 0;

ft.chrg.cpMax = -1;

ft.lpstrText = "|";

long lPos = FindText(0, &ft);

 

如果要继续查找，修改cpMin,如

int nCount = 0;

do

{

long lPos = GetRichEditCtrl().FindText(0, &ft);

if( -1 == lPos) break;

ft.chrg.cpMin = lPos + strlen(ft.lpstrText);

++nCount;

}while(TRUE);

 

6. 以Html格式保存RichEdit控件中的内容

临时做法可先转为RTF格式，再通过RTF-to-HTML Converter，参考如下文章：

http://www.codeguru.com/Cpp/controls/richedit/conversions/article.php/c5377/

 

8.   
重载OnProtected函数以得到RichEdit对应的消息，如粘贴等

 

void CRichEditorView::OnProtected(NMHDR* pNMHDR, LRESULT* pResult)

{

ENPROTECTED* pEP = (ENPROTECTED*)pNMHDR;

switch (pEP->msg)

{

case WM_KEYDOWN: //按键，判断pEP->wParam

case WM_PASTE: //粘贴

case WM_CUT: //剪切

case EM_SETCHARFORMAT:

default:

break;

};

*pResult = FALSE;

}

 

 

聊天常用

1. 设置RichEdit控件的链接功能（只能用在RICHED20以上）

Ø        
LoadLibrary(_T("Riched20.dll"));

Ø        
创建RichEdit2.0控件

CreateEx(0, _T("RichEdit20A"), NULL, WS_CHILD|WS_VISIBLE|WS_VSCROLL|WS_TABSTOP |ES_READONLY|ES_WANTRETURN|ES_MULTILINE, rect.left, rect.top, cx, cy, pParentWnd->m_hWnd, (HMENU)nID, NULL);

Ø        
设置选中的文字为链接显示

CHARFORMAT2 cf2;

ZeroMemory(&cf2, sizeof(CHARFORMAT2));//

cf2.cbSize = sizeof(CHARFORMAT2);

cf2.dwMask = CFM_LINK;

cf2.dwEffects |= CFE_LINK;

m_cRichEdit.SendMessage(EM_SETCHARFORMAT, SCF_SELECTION, (LPARAM)&cf2);

Ø        
支持链接的点击响应
m_cRichEdit.SetEventMask(ENM_LINK);

Ø        
响应链接的点击EN_LINK

BEGIN_MESSAGE_MAP(CMyRichEdit, CRichEditCtrl)
ON_NOTIFY_REFLECT(EN_LINK, OnURL)
END_MESSAGE_MAP()
......

void CMyRichEdit::OnURLClick(NMHDR *pNmhdr, LRESULT *pResult)

{

TCHAR LinkChar[512];

ENLINK *pLink = (ENLINK *)pNmhdr;

if (pLink->msg == WM_LBUTTONUP)

{

SetSel(penLink->chrg); //这是链接的文字范围

long Res = GetSelText((char *)LinkChar); //这是链接文字

…

}

}

Ø        
自动识别链接

UINT nMask = SendDlgItemMessage(IDC_RICHEDIT_MESSAGE, EM_GETEVENTMASK, 0, 0);

SendDlgItemMessage(IDC_RICHEDIT_MESSAGE, EM_SETEVENTMASK, 0, nMask | NM_LINK);

SendDlgItemMessage(IDC_RICHEDIT_MESSAGE, EM_AUTOURLDETECT, TRUE, 0);

BOOL OnNotify(WPARAM wParam, LPARAM lParam, LRESULT* pResult)

{

NMHDR* pNmHdr = (NMHDR *)lParam;

if(pNmHdr->idFrom == IDC_RICHEDIT_MESSAGE && pNmHdr->code == EN_LINK)

{

ENLINK *pLink = (ENLINK *)lParam;

if (pLink->msg == WM_LBUTTONDOWN)

{

SendDlgItemMessage(IDC_RICHEDIT_MESSAGE, EM_EXSETSEL, 0, (LPARAM)&(pLink->chrg));

ShellExecute(GetSafeHwnd(), "open", m_wndREMessage.GetSelText(), 0, 0, SW_SHOWNORMAL);

}

}

return CDialog::OnNotify(wParam, lParam, pResult);
}