윈도우 api 메모장을 만드는데..

#include <windows.h>

LRESULT CALLBACK WndProc(HWND hwnd, UINT iMsg,

WPARAM wParam, LPARAM lParam);

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,

LPSTR lpszCmdLine, int nCmdShow)

{

HWND hwnd;

MSG msg;

WNDCLASS WndClass;

WndClass.style = CS_HREDRAW | CS_VREDRAW;

WndClass.lpfnWndProc = WndProc;

WndClass.cbClsExtra = 0;

WndClass.cbWndExtra = 0;

WndClass.hInstance = hInstance;

WndClass.hIcon = LoadIcon(NULL, IDI_APPLICATION);

WndClass.hCursor = LoadCursor(NULL, IDC_ARROW);

WndClass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);

WndClass.lpszMenuName = NULL;

WndClass.lpszClassName = "Window Class Name";

RegisterClass(&WndClass);

hwnd = CreateWindow("Window Class Name",

"Window Title Name",

WS_OVERLAPPEDWINDOW,

CW_USEDEFAULT,

NULL,

hInstance,

NULL

);

ShowWindow(hwnd, nCmdShow);

UpdateWindow(hwnd);

while (GetMessage(&msg, NULL, 0, 0))

{

TranslateMessage(&msg);

DispatchMessage(&msg);

}

return (int)msg.wParam;

}

LRESULT CALLBACK WndProc(HWND hwnd, UINT iMsg,

WPARAM wParam, LPARAM lParam)

{

HDC hdc;

PAINTSTRUCT ps;

static char str[100][100];

static int count, yPos, ycnt, xPos;

static SIZE size;

int idx;

switch (iMsg)

{

case WM_CREATE:

count = 0;

yPos = 0;

xPos = 0;

CreateCaret(hwnd, NULL, 5, 15);

ShowCaret(hwnd);

break;

case WM_KEYDOWN:

switch(wParam)

{

case VK_DOWN:

yPos += 20;

break;

case VK_UP:

yPos -= 20;

break;

case VK_LEFT:

break;

case VK_RIGHT:

break;

}

case WM_PAINT:

idx = 0;

hdc = BeginPaint(hwnd, &ps);

while ( idx <= ycnt){

GetTextExtentPoint(hdc, str [idx], strlen(str [idx]), &size);

TextOut(hdc, 0, idx * 20, str [idx], strlen(str [idx]));

idx++;

SetCaretPos(size.cx, yPos);

}

EndPaint(hwnd, &ps);

break;

case WM_CHAR:

if (wParam == VK_BACK) count--;

else if (wParam == VK_RETURN)

{

count = 0;

ycnt++;

yPos = yPos + 20;

}

else

str[ycnt][count++] = wParam;

str[ycnt][count] = '\0';

InvalidateRgn(hwnd, NULL, TRUE);

break;

case WM_DESTROY:

HideCaret(hwnd);

DestroyCaret();

PostQuitMessage(0);

break;

}

return(DefWindowProc(hwnd, iMsg, wParam, lParam));

}

이렇게 짰는데요.. Caret을 적히는 문자에 맞춰 이동시키다보니 size.cx를 x좌표로 하는데.. y좌표는 yPos.

문제는 방향키로 Caret을 원하는위치로 이동시켜야 하는데 y좌표가 지정되어있는 yPos는 손쉽게 +-20으로 UP, DOWN을 작동시켰습니다만..

LEFT, RIGHT가 안됩니다 ㅠㅠ

따로 xPos로 줘서 이동시킬려니 Caret이 문자에 따라 맞춰서 이동이 안됩니다 ㅠㅠ

어떻게 해야하나요?