===總結=============================================我使用 QNetworkAccessManager 和 QNetworkRequests 同時下載兩個圖像。我如何確定兩次下載已完成？===詳細說明=================================我有兩個圖像的 URL，我想異步下載它們。為此，我初始化 QNetworkAccessManager 并使用兩個 QNetworkRequest。完成后，每個請求都會將圖像的內容寫入文件中。問題是兩個請求彼此一無所知，因此無法驗證另一個請求是否已完成。您能告訴我如何等待這兩個請求完成嗎？這是完整的代碼：import sysfrom PyQt5.QtCore import QUrl, QFile, QIODevicefrom PyQt5.QtNetwork import QNetworkAccessManager, QNetworkRequestfrom PyQt5.QtWidgets import QApplication, QWidgetclass MainWindow(QWidget): def __init__(self): super(MainWindow, self).__init__() img_url1 = "https://somesite.com/image1.jpg" img_url2 = "https://somesite.com/image2.jpg" self.downloader = QNetworkAccessManager() self.requests = [] self.temp_files = [] for index, mediafile_url in enumerate([img_url1, img_url2]): self.requests.append(self.downloader.get(QNetworkRequest(QUrl(mediafile_url)))) request = self.requests[index] self.temp_files.append(QFile(f'{mediafile_url.split("/")[-1]}')) temp_file = self.temp_files[index] request.finished.connect(lambda *args, r=request, tf=temp_file: self.download_image(r, tf)) self.show() @staticmethod def download_image(request, temp_file): image_data = request.readAll() temp_file.open(QIODevice.WriteOnly) temp_file.write(image_data) temp_file.close()app = QApplication(sys.argv)window = MainWindow()app.exec_()
1 回答
MMMHUHU
TA貢獻1834條經驗 獲得超8個贊
您必須創建一個跟蹤下載的類：
from dataclasses import dataclass
import sys
from PyQt5.QtCore import pyqtSignal, QObject, QUrl, QFile, QIODevice
from PyQt5.QtNetwork import QNetworkAccessManager, QNetworkRequest, QNetworkReply
from PyQt5.QtWidgets import QApplication, QWidget
@dataclass
class DownloadRequest:
url: QUrl
filename: str
class DownloadManager(QObject):
finished = pyqtSignal()
def __init__(self, parent=None):
super().__init__(parent)
self._manager = QNetworkAccessManager()
self._pending_downloads = 0
self.manager.finished.connect(self.handle_finished)
@property
def manager(self):
return self._manager
@property
def pending_downloads(self):
return self._pending_downloads
def download(self, requests):
for request in requests:
qrequest = QNetworkRequest(request.url)
qrequest.setAttribute(QNetworkRequest.User, request.filename)
self.manager.get(qrequest)
self._pending_downloads += 1
def handle_finished(self, reply):
self._pending_downloads -= 1
if reply.error() != QNetworkReply.NoError:
print(f"code: {reply.error()} message: {reply.errorString()}")
else:
print("successful")
filename = reply.attribute(QNetworkRequest.User)
file = QFile(filename)
if file.open(QIODevice.WriteOnly):
file.write(reply.readAll())
print(f"pending downloads {self.pending_downloads}")
if self.pending_downloads == 0:
self.finished.emit()
class MainWindow(QWidget):
def __init__(self, parent=None):
super().__init__(parent)
self._manager = DownloadManager()
self._manager.finished.connect(self.handle_finished)
img_url1 = "https://docs.python.org/3/_static/py.png"
img_url2 = "https://somesite.com/image2.jpg"
request1 = DownloadRequest(QUrl(img_url1), img_url1.split("/")[-1])
request2 = DownloadRequest(QUrl(img_url2), img_url2.split("/")[-1])
self._manager.download([request1, request2])
def handle_finished(self):
print("finished")
def main():
app = QApplication(sys.argv)
window = MainWindow()
window.show()
app.exec_()
if __name__ == "__main__":
main()
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