import time

import win32api
import win32gui
import win32ui
import win32con
from PIL import Image

def capture_screenshot(left, top, width, height, filename):
    # 获取桌面窗口的句柄
    hdesktop = win32gui.GetDesktopWindow()

    # 获取设备上下文
    desktop_dc = win32gui.GetWindowDC(hdesktop)
    img_dc = win32ui.CreateDCFromHandle(desktop_dc)

    # 创建一个兼容DC
    mem_dc = img_dc.CreateCompatibleDC()

    # 创建一个位图对象
    screenshot = win32ui.CreateBitmap()
    screenshot.CreateCompatibleBitmap(img_dc, width, height)

    # 将位图选入内存DC
    mem_dc.SelectObject(screenshot)

    # 使用BitBlt函数从屏幕复制到内存DC
    mem_dc.BitBlt((0, 0), (width, height), img_dc, (left, top), win32con.SRCCOPY)

    # 将位图保存为文件
    screenshot.SaveBitmapFile(mem_dc, filename)

    # 释放对象
    mem_dc.DeleteDC()
    win32gui.DeleteObject(screenshot.GetHandle())
    win32gui.ReleaseDC(hdesktop, desktop_dc)

# 示例调用函数
old=time.time()
capture_screenshot(100, 100, 500, 400, 'screenshot.bmp')
print(time.time()-old)