PrintWindow函数在notepad.exe中出错

Question

Win32API中的PrintWindow函数可以捕获程序的图像。通过以下代码，我们可以在剪贴板中获得屏幕截图的副本。

#define _WIN32_WINNT    0x0501        
#include <windows.h>
#include <iostream>
using namespace std;
WCHAR programName[] = L"Notepad";
int main()
{
HWND hwnd = FindWindow(programName, NULL);
if (hwnd == NULL)
{
cerr << "Cannot find window" << endl;
return -1;
}
WINDOWINFO wi;
wi.cbSize = sizeof(WINDOWINFO);
GetWindowInfo(hwnd, &wi);
RECT rc = {
wi.rcClient.left - wi.rcWindow.left,
wi.rcClient.top - wi.rcWindow.top,
wi.rcClient.right - wi.rcWindow.left,
wi.rcClient.bottom - wi.rcWindow.top
};
HDC hdcScreen = GetDC(NULL);
HDC hdc = CreateCompatibleDC(hdcScreen);
HBITMAP hbmp = CreateCompatibleBitmap(hdcScreen,
wi.rcWindow.right - wi.rcWindow.left,
wi.rcWindow.bottom - wi.rcWindow.top);
SelectObject(hdc, hbmp);
HBITMAP hbmp2 = CreateCompatibleBitmap(hdcScreen,
wi.rcClient.right - wi.rcClient.left,
wi.rcClient.bottom - wi.rcClient.top);
HDC hdc2 = CreateCompatibleDC(hdcScreen);
SelectObject(hdc2, hbmp2);
PrintWindow(hwnd, hdc, 0);
BitBlt(hdc2,
0, 0, rc.right - rc.left, rc.bottom - rc.top,
hdc,
rc.left, rc.top,
SRCCOPY);
OpenClipboard(NULL);
EmptyClipboard();
SetClipboardData(CF_BITMAP, hbmp2);
CloseClipboard();
DeleteDC(hdc);
DeleteObject(hbmp);
DeleteDC(hdc2);
DeleteObject(hbmp2);
ReleaseDC(NULL, hdcScreen);
cout << "Success" << endl;
return 0;
}

当我使用该代码捕获屏幕截图时，它可以工作，但会将错误的图片返回到我的剪贴板中。像这样：notepad.exe 的屏幕截图

这似乎是记事本程序的一部分。但为什么它只是程序的一部分。我试过其他程序，效果很好。notepad或win32api中有漏洞吗？

Answer 1

您只能获得客户端区域。此代码获取整个窗口：

HWND hwnd = FindWindow(programName, nullptr);
if (hwnd == nullptr)
return -1;
WINDOWINFO wi;
wi.cbSize = sizeof(WINDOWINFO);
GetWindowInfo(hwnd, &wi);
const LONG w = wi.rcWindow.right - wi.rcWindow.left;
const LONG h = wi.rcWindow.bottom - wi.rcWindow.top;
HDC hdcScreen = GetDC(nullptr);
HDC hdc = CreateCompatibleDC(hdcScreen);
HBITMAP hbmp = CreateCompatibleBitmap(hdcScreen, w, h);
SelectObject(hdc, hbmp);
PrintWindow(hwnd, hdc, 0); // or use PW_RENDERFULLCONTENT
BitBlt(hdc, 0, 0, w, h, hdc, 0, 0, SRCCOPY);
OpenClipboard(nullptr);
EmptyClipboard();
SetClipboardData(CF_BITMAP, hbmp);
CloseClipboard();
DeleteDC(hdc);
DeleteObject(hbmp);
ReleaseDC(nullptr, hdcScreen);
return 0;