SDK子类化文本框

#include "framework.h"
#include "17_SDK_sky.h"

//子类化（subclassing）一个编辑控件。通常子类化的时候，我们会用SetWindowLongPtr或者SetWindowLong来替换窗口过程

// 新的编辑框过程函数
WNDPROC g_pfnOldEdtProc = NULL;
LRESULT CALLBACK NewEditproc(HWND hwnd, UINT nMsg, WPARAM w, LPARAM l) {
	if (nMsg == WM_CHAR) {
		if (!isalnum(w)) {
			return 0;
		}
	}
	return g_pfnOldEdtProc(hwnd, nMsg, w, l);
}


// 对话框回调函数
INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam) {
	switch (message) {
	case WM_INITDIALOG:
		return (INT_PTR)TRUE;
	case WM_COMMAND:
		if (LOWORD(wParam) == BTN_SUBCLASS) {
			// 替换文本框的过程函数
			//g_pfnOldEdtProc 会保存旧的过程函数指针，SetWindowLongPtr赋值给 g_pfnOldEdtProc，使其不再为 NULL。
			//g_pfnOldEdtProc = (WNDPROC)SetWindowLongPtr(GetDlgItem(hDlg, EDT_SUBCLASS), GWL_WNDPROC, (LONG_PTR)NewEditproc);
			g_pfnOldEdtProc = (WNDPROC)SetClassLong(GetDlgItem(hDlg, EDT_SUBCLASS), GWL_WNDPROC, (LONG_PTR)NewEditproc);//此处可以下断点模拟逆向调试
			
		}
		else if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL) {
			EndDialog(hDlg, LOWORD(wParam));
			return (INT_PTR)TRUE;
		}
		break;
	}
	return (INT_PTR)FALSE;
}

// 程序入口点
int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
	_In_opt_ HINSTANCE hPrevInstance,
	_In_ LPWSTR    lpCmdLine,
	_In_ int       nCmdShow) {
	return (int)DialogBox(hInstance, MAKEINTRESOURCE(IDD_ABOUTBOX), NULL, About);
}