win32api.ChangeDisplaySettings(devmode,0)

`win32api.ChangeDisplaySettings(devmode, 0)` 是 Windows 操作系统的 API 函数，其中 `devmode` 参数是一个 DEVMODE 结构体，用于存储显示模式的设置，而 `0` 表示无更改，通常作为第二个参数传递。这个函数的作用是改变当前显示器的工作模式，包括分辨率、刷新率、颜色深度等显示属性。

DEVMODE 结构体包含了丰富的显示设置信息，如宽度、高度、比特深度、刷新频率等。通过修改这个结构并调用 `ChangeDisplaySettings` 函数，可以临时改变桌面的显示设置，以便于测试或者在某些特定场景下使用。

例如，如果你想将屏幕分辨率改为全屏，并且开启双倍像素缩放：

from ctypes import windll, Structure, byref

# 定义 DEVMODE 结构
class DEVMODE(Structure):
    _fields_ = [
        ('dmDeviceName', c_wchar * 32),
        ('dmSpecVersion', wintypes.DWORD),
        ('dmDriverVersion', wintypes.DWORD),
        ('dmSize', wintypes.DWORD),
        ('dmDriverExtra', wintypes.DWORD),
        ('dmFields', wintypes.DWORD),
        ('dmLogPixels', wintypes.DWORD),
        ('dmBitsPerPel', wintypes.DWORD),
        ('dmPelsWidth', wintypes.DWORD),
        ('dmPelsHeight', wintypes.DWORD),
        ('dmColor', wintypes.DWORD),
        ('dmDuplex', wintypes.DWORD),
        ('dmYResolution', wintypes.DWORD),
        ('dmTTOption', wintypes.DWORD),
        ('dmCollate', wintypes.BOOL),
        ('dmFormName', c_wchar * 32),
        ('dmLogFont', LOGFONT),
        ('dmBitsPerByte', wintypes.DWORD),
        ('dmPelsHorzRes', wintypes.DWORD),
        ('dmPelsVertRes', wintypes.DWORD),
        ('dmDisplayFrequency', wintypes.DWORD),
        ('dmICMMethod', wintypes.DWORD),
        ('dmICMIntent', wintypes.DWORD),
        ('dmMediaType', wintypes.DWORD),
        ('dmDitherType', wintypes.DWORD),
        ('dmReserved1', wintypes.DWORD * 4),
        ('dmReserved2', wintypes.DWORD * 4)
    ]

# 设置新的显示模式
new_mode = DEVMODE()
new_mode.dmPelsWidth, new_mode.dmPelsHeight = 1920, 1080
new_mode.dmBitsPerPel = 32
new_mode.dmFields = DM_PELSWIDTH | DM_PELSHEIGHT | DM_BITSPERPEL

# 执行设置
windll.user32.ChangeDisplaySettings(byref(new_mode), 0)

# 使用完毕后恢复原始模式
windll.user32.ChangeDisplaySettings(byref(current_mode), 0)