MFC使用rich edit若干問題

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一般性問題

1.   
代碼編譯通過了，運行后RichEdit控件不顯示，在InitInstance中添加

BOOL CWinApp::InitInstance ()

{

…

AfxInitRichEdit(); - RichEdit 1.0

或 AfxInitRichEdit2(); - RichEdit 2.0

…

}

 

2.   
升級默認的RichEdit版本，默認的版本有BUG，在InitInstance中添加

BOOL CWinApp::InitInstance ()

{

…

LoadLibrary("RICHED20.DLL");

…

FreeLibrary();

}

 

如果是CRichEditView基類的話，可用如下消息機制:

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控件的輸入框中最后追加一行

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

 

4.   
限制RichEdit控件的字數

CRichEditCtrl.LimitText(long nChars)

 

5.   
設置RichEdit控件的換行切換

如果是CRichEditView基類的話，可用如下消息機制:

BOOL CRichEditView::OnInitialUpdate()

{

…

m_nWordWrap = WrapNone;

WrapChanged();

…

}

 

如果是在Dialog，可使用SetTargetDevice，並在RichEdit的屬性里面加上want
return

CRichEditCtrl.SetTargetDevice(m_dcTarget, GetPrintWidth());

 

WrapChanged實際上也是調用

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

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

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

 

6.   
設置RichEdit控件不帶格式的數據粘貼

CRichEditCtrl.PasteSpecial(CF_TEXT);

 

7.   
設置RichEdit控件的滾動條自動隨輸入滾動到最后一行

int nFirstVisible = CRichEditCtrl.GetFirstVisibleLine();

if (nFirstVisible > 0)
{

CRichEditCtrl.LineScroll(-nFirstVisible, 0);

}

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

8.設置RichEdit控件的撤銷輸入次數(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(默認值)，可通過EM_SETUNDOLIMIT設置最大次數

 

9.設置RichEdit控件的OnChange事件

EM_SETEVENTMASK 設置 ENM_CHANGE

long lMask = GetEventMask();

lMask |= ENM_CHANGE;

lMask &= ~ENM_PROTECTED;

SetEventMask(lMask);

 

10.設置RichEdit控件的只讀屬性

CRichEditCtrl::SetReadOnly(BOOL bReadOnly = TRUE );

通過設置PROTECTED實現選中的文本只讀，參見如下文章：

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

 

 

函數應用

1. 設置RichEdit控件的顯示字體

CHARFORMAT cf;

ZeroMemory(&cf, sizeof(CHARFORMAT));

cf.cbSize = sizeof(CHARFORMAT);

cf.dwMask|=CFM_BOLD;

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

cf.dwMask|=CFM_ITALIC;

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

cf.dwMask|=CFM_UNDERLINE;

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

cf.crTextColor = RGB(255,0,0); //設置顏色

cf.dwMask|=CFM_SIZE;

cf.yHeight =200; //設置高度

cf.dwMask|=CFM_FACE;

strcpy(cf.szFaceName ,_T("隸書")); //設置字體

CRichEditCtrl.SetSelectionCharFormat(cf);

 

2.設置RichEdit控件的顯示字體的行間距（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 成員 wNumbering
才起作用

1 項目符號，默認用PFN_BULLET.

2 使用阿拉伯數字 (1, 2, 3, ...).

3 使用小寫字母 (a, b, c, ...).

4 使用大寫字母 (A, B, C, ...).

5 使用小寫羅馬數字 (i, ii, iii, ...).

6 使用大寫羅馬數字 (I, II, III, ...).

7 自定義，字符見成員 wNumberingStart.

PFM_OFFSET 成員 dxOffset
才起作用，縮進，單位twips

PFM_STARTINDENT 成員 dxStartIndent
才起作用，首行縮進

PFM_SPACEAFTER 成員 dySpaceAfter
才起作用，段間距

PFM_LINESPACING 成員 dyLineSpacing
才起作用，行間距

 

3.設置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樣式加上

 

4.獲取或者寫入RichEdit控件的內容

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(主要用於RTF等格式輸出)

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; //設置用例參數,以便回調函數調用

es.pfnCallback = MyStreamOutCallback;

pmyRichEditCtrl->StreamOut(SF_RTF, es);

 

讀入可以此類推，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);

 

如果要繼續查找，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控件中的內容

臨時做法可先轉為RTF格式，再通過RTF-to-HTML Converter，參考如下文章：

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

 

8.   
重載OnProtected函數以得到RichEdit對應的消息，如粘貼等

 

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

{

ENPROTECTED* pEP = (ENPROTECTED*)pNMHDR;

switch (pEP->msg)

{

case WM_KEYDOWN: //按鍵，判斷pEP->wParam

case WM_PASTE: //粘貼

case WM_CUT: //剪切

case EM_SETCHARFORMAT:

default:

break;

};

*pResult = FALSE;

}

 

 

聊天常用

1. 設置RichEdit控件的鏈接功能（只能用在RICHED20以上）

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

Ø        
創建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        
設置選中的文字為鏈接顯示

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        
支持鏈接的點擊響應
m_cRichEdit.SetEventMask(ENM_LINK);

Ø        
響應鏈接的點擊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); //這是鏈接的文字范圍

long Res = GetSelText((char *)LinkChar); //這是鏈接文字

…

}

}

Ø        
自動識別鏈接

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);
}