Windows下自定义文本编辑控件-优快云博客

本文介绍如何在Windows环境下使用API自定义一个文本编辑控件，包括创建控件、绘制字符、处理键盘事件等功能，实现类似文本编辑器的基本操作。

第一次写博客，尽量以后写的好一点!

#include <windows.h>
static int CreatePosX, CreatePosY;//插入符的位置
static int nCaretOffsetY;//y的位置
static TCHAR *pCharMath;//字符缓冲区
static TEXTMETRIC tm;//字体的信息，比如字体的高和宽
static int nCharWide, nCharHigh;//字符的宽度和高度
static int nTVWide, nTVHigh;//窗口的宽度和高度
static int nCharLine, nCharRow;//每行每列字符的数目
#define BUFFER(x,y) *(pCharMath+y*nCharLine+x)//二维数组的某一位置
static LRESULT CALLBACK DrawProc(HWND, UINT, WPARAM, LPARAM);//消息处理函数声明
static HWND DrawEdit(HWND hwnd, int x, int y, int wide, int High, int id)
{
   HWND Hwnd;
   WNDCLASS DrawEdits;
   HINSTANCE hInst = GetModuleHandle(NULL);
   DrawEdits.cbClsExtra = 0;
   DrawEdits.cbWndExtra = 0;
   DrawEdits.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
   DrawEdits.hCursor = LoadCursor(NULL, IDC_IBEAM);
   DrawEdits.hIcon = LoadIcon(NULL, IDI_ERROR);
   DrawEdits.hInstance = hInst;
   DrawEdits.lpfnWndProc = DrawProc;
   DrawEdits.lpszClassName = TEXT("文本框");
   DrawEdits.lpszMenuName = NULL;
   DrawEdits.style = CS_HREDRAW | CS_VREDRAW;
   if (!RegisterClass(&DrawEdits))
   {
       MessageBox(NULL, TEXT("注册失败"), TEXT("警告"), MB_OK);
       return 0;
   }
   Hwnd = CreateWindow(TEXT("文本框"), NULL, WS_CHILD | WS_VISIBLE, x, y, wide, High, hwnd, NULL, hInst, NULL);
   return Hwnd;
}
static void DrawChar(HDC hDC, int x, int y, TCHAR *str, int num)
{
   RECT rect;
   SelectObject(hDC, GetStockObject(SYSTEM_FIXED_FONT));
   SetTextColor(hDC, RGB(255, 0, 0));//设置字体颜色
   SetBkMode(hDC, TRANSPARENT);
   rect.left = x;
   rect.top = y;
   rect.right = x + num * nCharWide;
   rect.bottom = y + nCharHigh;
   FillRect(hDC, &rect, (HBRUSH)GetStockObject(BLACK_BRUSH));
   TextOut(hDC, CreatePosX * nCharWide, CreatePosY * nCharHigh,
       &BUFFER(CreatePosX, CreatePosY), nCharLine - CreatePosX);
}
static LRESULT CALLBACK DrawProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
   int x, y;//循环变量
   HDC hdc;//设备句柄变量
   switch (msg)
   {
   case WM_CREATE:
       hdc = GetDC(hWnd);//获取设备句柄
       SelectObject(hdc, GetStockObject(SYSTEM_FIXED_FONT));//设置字体的宽度高度(现在是等宽字体SYSTEM_FIXED_FONT)
       GetTextMetrics(hdc, &tm);//获取字体的信息
       ReleaseDC(hWnd, hdc);//释放设备的句柄
       nCharWide = tm.tmAveCharWidth;//字体的宽度
       nCharHigh = tm.tmHeight;//字体的高度
       SetTextColor(hdc, RGB(255, 255, 255));//设置字体颜色
       nCaretOffsetY = 12;//插入符位置偏移
       return 0;
   case WM_SIZE:
       nTVWide = LOWORD(lParam);//窗口宽度
       nCharLine = max(1, nTVWide / nCharWide);//一行可以存多少个字符
       nTVHigh = LOWORD(lParam);//窗口高度
       nCharRow = max(1, nTVHigh / nCharHigh);//一列可以存多少个字符
       if (pCharMath != NULL)//判断字符缓冲区是否有字符，如果有就释放这个缓冲区
       {
           free(pCharMath);//如果有就释放这个缓冲区
       }
       pCharMath = (TCHAR*)malloc(nCharLine*nCharRow);
       if (pCharMath)
       {
           for (x = 0; x < nCharLine; x++)
           {
               for (y = 0; y < nCharRow; y++)
               {
                   BUFFER(x, y) == ' ';//初始化这个二维数组让每个位置都为空格
               }
           }
       }
       SetCaretPos(0, nCaretOffsetY);
       return 0;
   case WM_LBUTTONDOWN:
       SetFocus(hWnd);
       break;
   case WM_KEYDOWN:
       switch (wParam)
       {
       case VK_HOME:
           CreatePosX = 0;
           break;
       case VK_END:
           CreatePosX = nCharLine - 1;
           break;
       case VK_PRIOR:
           CreatePosY = 0;
           break;
       case VK_NEXT:
           CreatePosY = nCharRow - 1;
           break;
       case VK_LEFT:
           CreatePosX = max(CreatePosX - 1, 0);
       case VK_RIGHT:
           CreatePosX = max(CreatePosX + 1, nCharLine - 1);
           break;
       case VK_UP:
           CreatePosY = (CreatePosY , -1);
           break;
       case VK_DOWN:
           CreatePosY = (CreatePosY + 1, nCharRow - 1);
           break;
       case DELETE:
           for (x = CreatePosX; x < nCharLine; x++)
           {
               BUFFER(x, CreatePosY) = BUFFER(x + 1, CreatePosY);
           }
           BUFFER(nCharLine - 1, CreatePosY) = ' ';
           HideCaret(hWnd);
           hdc = GetDC(hWnd);
           DrawChar(hdc, CreatePosX*nCharWide, CreatePosY*nCharHigh, &BUFFER(CreatePosX, CreatePosY), nCharLine - CreatePosX / nCharWide);
           ReleaseDC(hWnd, hdc);
           ShowCaret(hWnd);
           break;
       }
       SetCaretPos(CreatePosX*nCharWide, CreatePosY*nCharHigh + nCaretOffsetY);
       return 0;
   case WM_SHOWWINDOW:
       SetFocus(hWnd);
       break;
   case WM_SETFOCUS:
       CreateCaret(hWnd, NULL, 2, nCharHigh);
       SetCaretPos(CreatePosX*nCharWide, CreatePosY*nCharLine + nCaretOffsetY);
       ShowCaret(hWnd);
       break;
   case WM_KILLFOCUS:
   case WM_DESTROY:
       HideCaret(hWnd);//隐藏插入符
       DestroyCaret();//发送关闭消息
       break;
   case WM_CHAR:
       switch (wParam)
       {
       case 0X08:
           if (CreatePosX > 0)
           {
               CreatePosX--;
               SendMessage(hWnd, WM_KEYDOWN, VK_DELETE, 1L);
           }
           break;
       case 0X09:
           do
           {
               SendMessage(hWnd, WM_CHAR, TEXT(' '), 2L);
           } while (CreatePosX % 4 != 0);
           break;
       case 0X0D:
           CreatePosX = 0;
           if (++CreatePosY == nCharRow)
           {
               CreatePosY = 0;
           }
           break;
       case 0X1B:
       case 0X0A:
           MessageBeep((UINT)-1);
           break;
       default:
           BUFFER(CreatePosX, CreatePosY) = (TCHAR)wParam;
           HideCaret(hWnd);
           hdc = GetDC(hWnd);
           DrawChar(hdc, CreatePosX*nCharWide, CreatePosY*nCharHigh, &BUFFER(CreatePosX, CreatePosY), -1);
           ReleaseDC(hWnd, hdc);
           ShowCaret(hWnd);
           if (++CreatePosX == nCharLine)
           {
               CreatePosX = 0;
               if (++CreatePosY == 0)
               {
                   CreatePosY = 0;
               }
           }
           break;
       }
       SetCaretPos(CreatePosX*nCharWide, CreatePosY*nCharHigh + nCaretOffsetY);
       return 0;
   case WM_PAINT:
   {
                   PAINTSTRUCT ps;
                   hdc = BeginPaint(hWnd, &ps);
                   SelectObject(hdc, GetStockObject(SYSTEM_FIXED_FONT));
                   SetBkMode(hdc, TRANSPARENT);
                   SetTextColor(hdc, RGB(255, 255, 255));
                   for (y = 0; y < nCharLine; y++)
                   {
                       TextOut(hdc, 0, y*nCharHigh, &BUFFER(0, y), nCharLine);
                   }
                   EndPaint(hWnd, &ps);
   }
       return 0;
   default:
       break;
   }
   return DefWindowProc(hWnd, msg, wParam, lParam);
}