如何对非顶层EVE Online窗口截图？现有Python代码返回黑屏

一、解决全黑截图问题 #

EVE Online采用Direct3D硬件加速渲染，普通GDI截图（如BitBlt）无法捕获显存中的渲染内容，导致截图全黑。推荐两种可行方案：

1. 使用PrintWindow并指定PW_RENDERFULLCONTENT参数 #

该参数会强制窗口完整渲染内容，包括Direct3D绘制的部分：

import win32gui
import win32ui
import win32con
from PIL import Image

def capture_eve_window(hwnd):
    # 获取窗口客户区尺寸
    left, top, right, bottom = win32gui.GetClientRect(hwnd)
    width = right - left
    height = bottom - top

    # 获取窗口DC并创建兼容DC
    hwnd_dc = win32gui.GetWindowDC(hwnd)
    mfc_dc = win32ui.CreateDCFromHandle(hwnd_dc)
    save_dc = mfc_dc.CreateCompatibleDC()

    # 创建兼容位图
    save_bitmap = win32ui.CreateBitmap()
    save_bitmap.CreateCompatibleBitmap(mfc_dc, width, height)
    save_dc.SelectObject(save_bitmap)

    # 调用PrintWindow，传入强制渲染参数
    PW_RENDERFULLCONTENT = 0x00000002
    win32gui.PrintWindow(hwnd, save_dc.GetSafeHdc(), PW_RENDERFULLCONTENT)

    # 将HBITMAP转换为PIL Image
    bmp_info = save_bitmap.GetInfo()
    bmp_str = save_bitmap.GetBitmapBits(True)
    img = Image.frombuffer('RGB', (bmp_info['bmWidth'], bmp_info['bmHeight']), bmp_str, 'raw', 'BGRX', 0, 1)

    # 释放资源
    win32gui.DeleteObject(save_bitmap.GetHandle())
    save_dc.DeleteDC()
    mfc_dc.DeleteDC()
    win32gui.ReleaseDC(hwnd, hwnd_dc)

    return img

2. 使用DWM窗口缩略图（更稳定） #

若PrintWindow仍失效，可通过桌面窗口管理器（DWM）获取窗口缩略图数据：

import win32gui
import ctypes
from PIL import Image

# 定义DWM相关结构体
class DWM_THUMBNAIL_PROPERTIES(ctypes.Structure):
    _fields_ = [
        ("dwFlags", ctypes.c_uint),
        ("rcDestination", ctypes.wintypes.RECT),
        ("rcSource", ctypes.wintypes.RECT),
        ("opacity", ctypes.c_byte),
        ("fVisible", ctypes.c_bool),
        ("fSourceClientAreaOnly", ctypes.c_bool)
    ]

DWM_TNP_VISIBLE = 0x00000002
DwmRegisterThumbnail = ctypes.windll.dwmapi.DwmRegisterThumbnail
DwmUpdateThumbnailProperties = ctypes.windll.dwmapi.DwmUpdateThumbnailProperties
DwmUnregisterThumbnail = ctypes.windll.dwmapi.DwmUnregisterThumbnail

def capture_eve_dwm(hwnd):
    # 创建隐藏窗口接收缩略图
    hwnd_thumb = win32gui.CreateWindowEx(0, win32gui.GetStockObject(win32con.WNDCLASS), "", 0, 0, 0, 1, 1, 0, 0, 0, None)
    
    # 注册窗口缩略图
    h_thumb = ctypes.c_uint()
    DwmRegisterThumbnail(hwnd_thumb, hwnd, ctypes.byref(h_thumb))
    
    # 获取目标窗口尺寸
    left, top, right, bottom = win32gui.GetClientRect(hwnd)
    width = right - left
    height = bottom - top

    # 设置缩略图属性
    props = DWM_THUMBNAIL_PROPERTIES()
    props.dwFlags = DWM_TNP_VISIBLE
    props.fVisible = True
    props.rcDestination = ctypes.wintypes.RECT(0, 0, width, height)
    DwmUpdateThumbnailProperties(h_thumb, ctypes.byref(props))

    # 截取缩略图窗口内容
    hwnd_dc = win32gui.GetWindowDC(hwnd_thumb)
    mfc_dc = win32ui.CreateDCFromHandle(hwnd_dc)
    save_dc = mfc_dc.CreateCompatibleDC()
    save_bitmap = win32ui.CreateBitmap()
    save_bitmap.CreateCompatibleBitmap(mfc_dc, width, height)
    save_dc.SelectObject(save_bitmap)
    save_dc.BitBlt((0,0), (width, height), mfc_dc, (0,0), win32con.SRCCOPY)

    # 转换为PIL Image
    bmp_info = save_bitmap.GetInfo()
    bmp_str = save_bitmap.GetBitmapBits(True)
    img = Image.frombuffer('RGB', (bmp_info['bmWidth'], bmp_info['bmHeight']), bmp_str, 'raw', 'BGRX', 0, 1)

    # 清理资源
    DwmUnregisterThumbnail(h_thumb)
    win32gui.DestroyWindow(hwnd_thumb)
    win32gui.DeleteObject(save_bitmap.GetHandle())
    save_dc.DeleteDC()
    mfc_dc.DeleteDC()
    win32gui.ReleaseDC(hwnd_thumb, hwnd_dc)

    return img

二、处理CreateCompatibleBitmap生成的HBITMAP #

CreateCompatibleBitmap返回的HBITMAP句柄，在Python中可通过以下步骤转换为可操作图像：

1. 调用GetBitmapBits()获取位图原始字节数据
2. 结合GetInfo()获取的宽高信息，用PIL的Image.frombuffer()解析（注意GDI位图颜色格式为BGRX，需转换为RGB）

核心转换代码片段：

bmp_info = save_bitmap.GetInfo()
bmp_str = save_bitmap.GetBitmapBits(True)
img = Image.frombuffer('RGB', (bmp_info['bmWidth'], bmp_info['bmHeight']), bmp_str, 'raw', 'BGRX', 0, 1)

若需转换为numpy数组，直接执行：

import numpy as np
img_np = np.array(img)

内容的提问来源于stack exchange，提问作者Mr.Z