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#include <windows.h>
#include <tchar.h>
#include <stdexcept>
#define IDC_EDIT 1000
#define IDC_SAVE 1001
LPCSTR pszFileName = _T("Demo.txt");
TCHAR szClsName[] = _T("BasicApp");
TCHAR szWndName[] = _T("Template");
LRESULT CALLBACK WndProcedure(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam);
ATOM RegisterMyClass();
HWND CreateEditWnd(HWND hWnd, HINSTANCE hInstance);
HWND CreateSaveButton(HWND, HINSTANCE);
void SaveTextFileFromEdit(HWND hEdit);
class Win_error: public std::runtime_error
{
private:
std::string m_what;
public:
Win_error(): std::runtime_error("Windows Error")
{
LPVOID lpMsgBuf;
FormatMessage (FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, GetLastError(), 0,
(LPTSTR) &lpMsgBuf, 0,NULL);
m_what.assign((const char *)lpMsgBuf);
LocalFree(lpMsgBuf);
}
virtual const char* what()const
{
return m_what.c_str();
}
};
ATOM RegisterMyClass()
{
WNDCLASSEX WndClsEx;
WndClsEx.cbSize = sizeof(WNDCLASSEX);
WndClsEx.style = CS_HREDRAW | CS_VREDRAW;
WndClsEx.lpfnWndProc = WndProcedure;
WndClsEx.cbClsExtra = 0;
WndClsEx.cbWndExtra = 0;
WndClsEx.hIcon = LoadIcon(NULL, IDI_APPLICATION);
WndClsEx.hCursor = LoadCursor(NULL, IDC_ARROW);
WndClsEx.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
WndClsEx.lpszMenuName = NULL;
WndClsEx.lpszClassName = szClsName;
WndClsEx.hInstance = static_cast<HINSTANCE>(::GetModuleHandle(0));
WndClsEx.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
return RegisterClassEx(&WndClsEx);
}
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
MSG Msg;
HWND hWnd;
if (!RegisterMyClass())
return FALSE;
hWnd = CreateWindow(szClsName, szWndName, WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, 0, 0, hInstance, 0);
if (!hWnd)
return FALSE;
ShowWindow(hWnd, SW_SHOWNORMAL);
UpdateWindow(hWnd);
while (GetMessage(&Msg, NULL, 0, 0))
{
TranslateMessage(&Msg);
DispatchMessage(&Msg);
}
return (int)Msg.wParam;
}
LRESULT CALLBACK WndProcedure(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam)
{
HWND hEdit = 0;
try
{
switch (Msg)
{
case WM_CREATE:
CreateEditWnd(hWnd, (HINSTANCE)GetModuleHandle(0));
CreateSaveButton(hWnd, (HINSTANCE)GetModuleHandle(0));
break;
case WM_COMMAND:
if (LOWORD(wParam) == IDC_SAVE)
{
hEdit = GetDlgItem(hWnd, IDC_EDIT);
if (hEdit == 0)
throw Win_error();
SaveTextFileFromEdit(hEdit);
}
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
}
}
catch (std::exception& ex)
{
MessageBoxA(hWnd, ex.what(), "ERROR", MB_ICONERROR);
}
return DefWindowProc(hWnd, Msg, wParam, lParam);
}
HWND CreateEditWnd(HWND hWnd, HINSTANCE hInstance)
{
DWORD EditStyle = WS_CHILD|WS_VISIBLE|WS_BORDER|ES_MULTILINE;
HWND hEditWnd = CreateWindowA(_T("EDIT"), 0, EditStyle,
10, 10, 300, 300, hWnd, (HMENU)IDC_EDIT,
hInstance, 0);
if (hEditWnd == 0)
throw Win_error();
if (SetWindowTextA(hEditWnd, _T("Some demo text\r\nBla Bla Bla")) == 0)
throw Win_error();
return hEditWnd;
}
HWND CreateSaveButton(HWND hWnd, HINSTANCE hInstance)
{
DWORD ButtonStyle = WS_CHILD|WS_VISIBLE;
HWND hButtonWnd = CreateWindowA(_T("BUTTON"), _T("Save"), ButtonStyle,
320, 10, 50, 25, hWnd, (HMENU)IDC_SAVE,
hInstance, 0);
if (hButtonWnd == 0)
throw Win_error();
return hButtonWnd;
}
void SaveTextFileFromEdit(HWND hEdit)
{
HANDLE hFile;
if(!IsWindow(hEdit))
throw std::runtime_error("hEdit is invalid");
hFile = CreateFile(pszFileName, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
if (hFile == INVALID_HANDLE_VALUE)
throw Win_error();
DWORD dwTextLength = (DWORD)SendMessageA(hEdit, WM_GETTEXTLENGTH, 0, 0L);
if (dwTextLength == 0)
throw std::runtime_error("No text to save");
std::string buffer(dwTextLength + 1, ' ');
GetWindowTextA(hEdit, &buffer[0], dwTextLength + 1);
if(!WriteFile(hFile, &buffer[0], buffer.size(), &dwTextLength, 0))
{
CloseHandle(hFile);
throw Win_error();
}
MessageBoxA(0, "Text saved", "SUCCESS", MB_OK);
CloseHandle(hFile);
}
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