自定义编辑控件的边框

// Edit_1.cpp : Defines the entry point for the application.
//

#include "stdafx.h"
#include "Edit_1.h"
#include <windowsx.h>
#include <RichEdit.h>
#include <commctrl.h>

#pragma comment(lib,"Comctl32.lib")

#define MAX_LOADSTRING 100
#define IDC_PASTE 101

// Global Variables:
HINSTANCE hInst;                                // current instance
WCHAR szTitle[MAX_LOADSTRING];                  // The title bar text
WCHAR szWindowClass[MAX_LOADSTRING];            // the main window class name
HWND hwndEdit;
HMENU m_hMenu;
// Forward declarations of functions included in this code module:
ATOM                MyRegisterClass(HINSTANCE hInstance);
BOOL                InitInstance(HINSTANCE, int);
LRESULT CALLBACK    WndProc(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK    About(HWND, UINT, WPARAM, LPARAM);
//LRESULT CALLBACK    MyProc(HWND, UINT, WPARAM, LPARAM,UINT_PTR, DWORD_PTR);
LRESULT CALLBACK RichEditProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp, UINT_PTR, DWORD_PTR);

int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
                     _In_opt_ HINSTANCE hPrevInstance,
                     _In_ LPWSTR    lpCmdLine,
                     _In_ int       nCmdShow)
{
    UNREFERENCED_PARAMETER(hPrevInstance);
    UNREFERENCED_PARAMETER(lpCmdLine);

    // TODO: Place code here.

    // Initialize global strings
    LoadStringW(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
    LoadStringW(hInstance, IDC_EDIT1, szWindowClass, MAX_LOADSTRING);

    MyRegisterClass(hInstance);

    // Perform application initialization:
    if (!InitInstance (hInstance, nCmdShow))
    {
        return FALSE;
    }

    HACCEL hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_EDIT1));

    MSG msg;

    // Main message loop:
    while (GetMessage(&msg, nullptr, 0, 0))
    {
        if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    return (int) msg.wParam;
}



//
//  FUNCTION: MyRegisterClass()
//
//  PURPOSE: Registers the window class.
//
ATOM MyRegisterClass(HINSTANCE hInstance)
{
    WNDCLASSEXW wcex;

    wcex.cbSize = sizeof(WNDCLASSEX);

    wcex.style          = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc    = WndProc;
    wcex.cbClsExtra     = 0;
    wcex.cbWndExtra     = 0;
    wcex.hInstance      = hInstance;
    wcex.hIcon          = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_EDIT1));
    wcex.hCursor        = LoadCursor(nullptr, IDC_ARROW);
    wcex.hbrBackground  = (HBRUSH)(COLOR_WINDOW+3);
    wcex.lpszMenuName   = MAKEINTRESOURCEW(IDC_EDIT1);
    wcex.lpszClassName  = szWindowClass;
    wcex.hIconSm        = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));

    WNDCLASSEXW mywcex;
 

    return RegisterClassExW(&wcex);
}

//
//   FUNCTION: InitInstance(HINSTANCE, int)
//
//   PURPOSE: Saves instance handle and creates main window
//
//   COMMENTS:
//
//        In this function, we save the instance handle in a global variable and
//        create and display the main program window.
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
   hInst = hInstance; // Store instance handle in our global variable
   LoadLibrary(TEXT("Msftedit.dll"));
   HWND hWnd = CreateWindowW(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
      CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, nullptr, nullptr, hInstance, nullptr);
  
   if (!hWnd)
   {
      return FALSE;
   }

   ShowWindow(hWnd, nCmdShow);
   UpdateWindow(hWnd);

   return TRUE;
}

//
//  FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
//
//  PURPOSE: Processes messages for the main window.
//
//  WM_COMMAND  - process the application menu
//  WM_PAINT    - Paint the main window
//  WM_DESTROY  - post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    
    MENUITEMINFO mii;
    WCHAR lpszText[] = L"Paste";
    
    switch (message)
    {
    case WM_CREATE:
    {
        hwndEdit = CreateWindowEx(0, MSFTEDIT_CLASS, TEXT("EDIT"),
             WS_VISIBLE | WS_CHILD | WS_BORDER | ES_LEFT,
            20, 20, 100, 30,
            hWnd, NULL, hInst, NULL);
        HWND hwndEdit1 = CreateWindowEx(0, MSFTEDIT_CLASS, TEXT("EDIT"),
            WS_VISIBLE | WS_CHILD | WS_BORDER | ES_LEFT,
            150, 20, 100, 30,
            hWnd, NULL, hInst, NULL);

        SetWindowSubclass(hwndEdit, RichEditProc, 0, 0);
        SetWindowPos(hwndEdit, NULL, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_FRAMECHANGED);

    }
    break;
    case WM_COMMAND:
        {
            int wmId = LOWORD(wParam);
            // Parse the menu selections:
            switch (wmId)
            {
            case IDC_PASTE:
            {
                SetForegroundWindow(hwndEdit);
                INPUT ip;
                ip.type = INPUT_KEYBOARD;
                ip.ki.wScan = 0;
                ip.ki.time = 0;
                ip.ki.dwExtraInfo = 0;
                // Press the "Ctrl" key
                ip.ki.wVk = VK_CONTROL;
                ip.ki.dwFlags = 0; // 0 for key press
                SendInput(1, &ip, sizeof(INPUT));

                // Press the "V" key
                ip.ki.wVk = 'V';
                ip.ki.dwFlags = 0; // 0 for key press
                SendInput(1, &ip, sizeof(INPUT));

                // Release the "V" key
                ip.ki.wVk = 'V';
                ip.ki.dwFlags = KEYEVENTF_KEYUP;
                SendInput(1, &ip, sizeof(INPUT));

                // Release the "Ctrl" key
                ip.ki.wVk = VK_CONTROL;
                ip.ki.dwFlags = KEYEVENTF_KEYUP;
                SendInput(1, &ip, sizeof(INPUT));
            }
                break;
            case IDM_ABOUT:
                DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
                break;
            case IDM_EXIT:
                DestroyWindow(hWnd);
                break;
            default:
                return DefWindowProc(hWnd, message, wParam, lParam);
            }
        }
        break;

    case WM_CONTEXTMENU:
        if ((HWND)wParam == hwndEdit) 
        {
            m_hMenu = CreatePopupMenu();
            InsertMenu(m_hMenu, 0, MF_BYCOMMAND | MF_STRING | MF_ENABLED, IDC_PASTE, L"Paste");
            TrackPopupMenu(m_hMenu, TPM_TOPALIGN | TPM_LEFTALIGN, GET_X_LPARAM(lParam), GET_Y_LPARAM(lParam), 0, hWnd, NULL);
        }
        break;

    case WM_PAINT:
        {
            PAINTSTRUCT ps;
            HDC hdc = BeginPaint(hWnd, &ps);
            // TODO: Add any drawing code that uses hdc here...
            EndPaint(hWnd, &ps);
        }
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}

// Message handler for about box.
INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
    UNREFERENCED_PARAMETER(lParam);
    switch (message)
    {
    case WM_INITDIALOG:
        return (INT_PTR)TRUE;

    case WM_COMMAND:
        if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
        {
            EndDialog(hDlg, LOWORD(wParam));
            return (INT_PTR)TRUE;
        }
        break;
    }
    return (INT_PTR)FALSE;
}

LRESULT CALLBACK RichEditProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp, UINT_PTR, DWORD_PTR)
{
    static int border_thickness = 1;
    TCHAR szText[40];
    HBRUSH hBrush;
    RECT rect;
    switch (msg)
    {    
   
    case WM_NCPAINT:
    {
        HDC hdc = GetWindowDC(hwnd);
        RECT rc;
        GetClientRect(hwnd, &rc);
        rc.right += 2 * border_thickness + 1;
        rc.bottom += 2 * border_thickness + 1;

        HBRUSH hbrush = (HBRUSH)GetStockObject(NULL_BRUSH);
        HPEN hpen = CreatePen(PS_SOLID, 2 * border_thickness, RGB(255, 0, 0));
        HBRUSH oldbrush = (HBRUSH)SelectObject(hdc, hbrush);
        HPEN oldpen = (HPEN)SelectObject(hdc, hpen);
        Rectangle(hdc, rc.left, rc.top, rc.right, rc.bottom);
        SelectObject(hdc, oldpen);
        SelectObject(hdc, oldbrush);
        DeleteObject(hpen);
        DeleteObject(hbrush);

        ReleaseDC(hwnd, hdc);
        return 0;
    }
    case WM_NCCALCSIZE:
        if (lp)
        {
            NCCALCSIZE_PARAMS* sz = (NCCALCSIZE_PARAMS*)lp;
            InflateRect(&sz->rgrc[0], -border_thickness, -border_thickness);
            return 0;
        }
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefSubclassProc(hwnd, msg, wp, lp);
    }
    return 0;
}

Debug:

Note: 左边的是自绘的边框

参考： https://stackoverflow.com/questions/59732985/winapi-painting-rich-edit-thin-border