Чтение Digital PErsona HId 4500 Reader на Python с использованием типов C ⇐ Python

[Anonymous]

Я новичок в программировании, использую пример кода C# из SDK Digital persona на Python.
Я прочитал SDK и не нашел точного преобразования, за исключением кода для прочитайте USB-считыватель отпечатков пальцев и зарегистрируйте отпечатки пальцев, соответствующие человеку.
Коды обнаруживают USB-считыватель, он включается, но код нет. Знайте, как интерпретировать и вернуть эту ошибку:
Результат dpfpdd_init: 0
dpfpdd_query_devices (count) результат: 96075789, device_count: 1
Нажмите любую клавишу, чтобы продолжить. . .
Это код:
import sys
import ctypes
from ctypes import *
from PyQt5.QtWidgets import QApplication, QMainWindow, QLabel, QVBoxLayout, QWidget, QPushButton, QListWidget
from PyQt5.QtGui import QImage, QPixmap

class FingerprintApp(QMainWindow):
def __init__(self):
super().__init__()

self.setWindowTitle("Fingerprint Scanner")
self.setGeometry(100, 100, 600, 400)

self.layout = QVBoxLayout()

self.label = QLabel("Press the button to scan fingerprint", self)
self.layout.addWidget(self.label)

self.device_list_label = QLabel("No devices found", self)
self.layout.addWidget(self.device_list_label)

self.device_list = QListWidget(self)
self.layout.addWidget(self.device_list)

self.button = QPushButton("Scan Fingerprint", self)
self.button.clicked.connect(self.scan_fingerprint)
self.layout.addWidget(self.button)

container = QWidget()
container.setLayout(self.layout)
self.setCentralWidget(container)

self.device_handle = c_void_p()

def scan_fingerprint(self):
dll_path = "C:\\Program Files\\DigitalPersona\\U.are.U SDK\\Windows\\Lib\\x64\\dpfpdd.dll"

try:
dpfpddDll = ctypes.CDLL(dll_path)
except OSError:
self.label.setText(f"Library not found at {dll_path}")
return

if not self.init_dpfpdd(dpfpddDll):
return

self.query_device(dpfpddDll)

def init_dpfpdd(self, dpfpddDll):
dpfpdd_init = dpfpddDll.dpfpdd_init
dpfpdd_init.argtypes = []
dpfpdd_init.restype = c_int
result = dpfpdd_init()
print(f"dpfpdd_init result: {result}")

if result != 0:
self.label.setText("Initialization failed")
return False
return True

def query_device(self, dpfpddDll):
class DPFPDD_DEV_INFO(Structure):
_fields_ = [
("size", c_uint),
("name", c_char * 32),
("modality", c_uint),
("technology", c_uint),
("version", c_uint),
("serial_num", c_char * 32),
("prv", c_void_p),
]

dpfpdd_query_devices = dpfpddDll.dpfpdd_query_devices
dpfpdd_query_devices.argtypes = [POINTER(c_uint), POINTER(POINTER(DPFPDD_DEV_INFO))]
dpfpdd_query_devices.restype = c_int

device_count = c_uint(0)
device_info_buffer = POINTER(DPFPDD_DEV_INFO)()

result = dpfpdd_query_devices(byref(device_count), byref(device_info_buffer))
print(f"dpfpdd_query_devices (count) result: {result}, device_count: {device_count.value}")

if result != 0 or device_count.value == 0:
self.device_list_label.setText("No devices found")
return

self.device_list_label.setText(f"Devices found: {device_count.value}")
for i in range(device_count.value):
device_info = device_info_buffer
device_name = device_info.name.decode('utf-8')
self.device_list.addItem(device_name)
self.device_list.currentItemChanged.connect(lambda: self.open_device(dpfpddDll, device_name.encode('ascii')))

def open_device(self, dpfpddDll, device_name):
dpfpdd_open = dpfpddDll.dpfpdd_open
dpfpdd_open.argtypes = [c_char_p, POINTER(c_void_p)]
dpfpdd_open.restype = c_int

result = dpfpdd_open(device_name, byref(self.device_handle))
print(f"dpfpdd_open result: {result}, device_handle: {self.device_handle}")

if result != 0:
self.label.setText(f"Failed to open device, error code: {result}")
return

self.capture_fingerprint(dpfpddDll)

def capture_fingerprint(self, dpfpddDll):
dpfpdd_capture = dpfpddDll.dpfpdd_capture
dpfpdd_capture.argtypes = [c_void_p, c_uint, POINTER(c_ubyte), POINTER(c_uint)]
dpfpdd_capture.restype = c_int

timeout = 5000 # 5 seconds

capture_size = c_uint(512 * 512) # Adjust the buffer size
capture_buffer = (c_ubyte * capture_size.value)()

print(f"Before capture: device_handle={self.device_handle}, timeout={timeout}, capture_size={capture_size.value}")
result = dpfpdd_capture(self.device_handle, timeout, capture_buffer, byref(capture_size))
print(f"dpfpdd_capture result: {result}, capture_size: {capture_size.value}")

if result != 0:
self.label.setText(f"Failed to capture fingerprint, error code: {result}")
return

if capture_size.value == 0:
self.label.setText("Capture buffer is empty")
return

image_data = bytes(capture_buffer[:capture_size.value])
image = QImage(image_data, 512, 512, QImage.Format_Grayscale8) # Adjust the image dimensions as needed
pixmap = QPixmap.fromImage(image)
self.image_label.setPixmap(pixmap)
self.image_label.setScaledContents(True)

if __name__ == "__main__":
app = QApplication(sys.argv)
window = FingerprintApp()
window.show()
sys.exit(app.exec_())



Подробнее здесь: https://stackoverflow.com/questions/786 ... ng-c-types