RichEdit关键字高亮的简单实现

RichEdit控件基本使用在网上介绍的已经很多了，在这里就不多说了。

直接进入正题：

                                   在RichEdit中实现关键字高亮的简单方法。

如果要真正实现RichEdit的关键字高亮，那么基本需要把整个RichEdit控件都重写一遍，需要很大的工作量。

既然不想花太大的力气实现，那实现出来的效果多少会有些差别。

在这里，实现的方式是在RichEdit中边输入边接收信息，逐一和已存的关键字比对。

                       

首先先将RichEdit创建出来：

                 

	RichEdit = CreateWindowEx(WS_EX_CLIENTEDGE,
			TEXT("RichEdit20A"),NULL,
			ES_MULTILINE | WS_CHILD |WS_VISIBLE |WS_VSCROLL |WS_HSCROLL | ES_WANTRETURN,
			170,	80,	rcClient.right-180,	rcClient.bottom/2-60,
			hWnd,	0,	hInstance,	NULL);

                                                                                                 在这之前不要忘记加上RichEdit的头文件  #include "RichEdit.h"和 hInst = LoadLibrary(TEXT("RICHED20.dll"));

由于要对RichEdit中的内容进行动态的改变，所以需要一个新的窗口回调函数：

char buffer[1024 *10];   //设置一个缓冲区，存放所接收到的字符
LRESULT CALLBACK EditProc( HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam )
{
	HDC hdc;
	DWORD FirstChar;
	RECT rect;
	TEXTRANGE txtrange;
	
	char keybuffer[1024];
	HRGN hRgn;
	HRGN hOldRgn;
	RECT RealRect;
	LRESULT	 nRet;
	
	switch(message)
	{
	case WM_PAINT:
		{
			nRet = CallWindowProc((WNDPROC)OldProc,hWnd,message,wParam,lParam);
			hdc = GetDC(hWnd);
			SendMessage(hWnd,EM_GETRECT,0,(LPARAM)&rect);
			LRESULT nPos = SendMessage(hWnd,EM_CHARFROMPOS,0,(LPARAM)&rect);

			LRESULT nLine = SendMessage(hWnd,EM_LINEFROMCHAR,nPos,0);
			
			LONG nIndex = SendMessage(hWnd,EM_LINEINDEX,nLine,0);
			txtrange.chrg.cpMin = nIndex;
			FirstChar = nIndex;
			LONG nNextPos = SendMessage(hWnd,EM_CHARFROMPOS,0,(LPARAM)&rect.right);
			txtrange.chrg.cpMax = nNextPos;
			RealRect.left = rect.left;
			RealRect.top = rect.top;
			RealRect.right = rect.right;
			RealRect.bottom = rect.bottom;
			hRgn = CreateRectRgn(RealRect.left,RealRect.top,RealRect.right,RealRect.bottom);
			hOldRgn = (HRGN)SelectObject(hdc,hRgn);

			txtrange.lpstrText = buffer;
			SendMessage(hWnd,EM_GETTEXTRANGE,0,(LPARAM)&txtrange);
			
			int i =0 ,j;

			while(buffer[i] != '\0' )  //进行关键字匹配
			{
				while(buffer[i] != '\0' &&(buffer[i] ==' ' || buffer[i] == '\r' || buffer[i] =='\t' ||
											buffer[i] == '\n' || buffer[i] == '(' || buffer[i] == ')'))
					i++;

				if(buffer[i] == '\0')
					break;

				for(j=0;buffer[i] != '\0' && buffer[i] !=' ' && buffer[i] != '\r' && buffer[i] !='\t' && buffer[i] != '\n' && buffer[i] != '(' && buffer[i] != ')'; i++,j++)
					keybuffer[j] = buffer[i];

				keybuffer[j]='\0';
			
				if(Check(keybuffer)==1)	     //对已存的关键字进行逐一比对
				{
					SetTextColor(hdc,RGB(0,0,255));

					int nWidth = SendMessage(RichEdit,EM_POSFROMCHAR,nIndex+i-j, 0);
					rect.left = LOWORD(nWidth) ;
					rect.top = HIWORD(nWidth);



					DrawText(hdc,keybuffer,-1,&rect,0);
				}

			}


			SelectObject(hdc,hOldRgn);
			DeleteObject(hRgn);
			ReleaseDC(hWnd,hdc);

		}
		break;
	default:
		return CallWindowProc((WNDPROC)OldProc, hWnd, message, wParam, lParam);
	}
	return nRet;
}

在初始化的时候进行下面的调用即可实现基本的关键字高亮：

OldProc = SetWindowLong(RichEdit, GWL_WNDPROC, (LONG)EditProc);//OldProc为全局LONG类型的变量

注：

关键字为自己设定，在我上边的例子中在Check（char *str）这样的函数进行对已存的关键字进行匹配。