我开发了一个GUI,用于从文件中提取一些数据 . 这个过程需要很长时间 . 在程序处理外部文件期间(使用subprocess.Popen),主GUI将不响应(如预期的那样) . 我想向用户添加一条带有振荡进度条的消息,让他知道程序正在运行并且只是挂在那里 . 我将进度条实现为QDialog,然后在调用long进程之前调用它 . 如果我使用[dialog.exec_()]方法调用进度条,程序将等待我的响应,这是对话框的结果 . 如果我关闭对话框,程序将继续,而不显示我想要显示的进度消息 . 如果我使用[dialog.show()]方法,那么我看到的只是一个空的白色窗口,其中应该是进度条 .
我尝试了多种变体,但没有成功 .
我在用:
Python 2.7.2
PyQt4: 4.9.1
Windows 7
以下是显示问题的示例代码 . 在dialog.exec()和dialog.show()之间切换以演示问题 .
import sys
import time
from PyQt4 import QtCore, QtGui
from PyQt4.QtCore import pyqtSignature
try:
_fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
_fromUtf8 = lambda s: s
class LongProcess(QtGui.QMainWindow):
def __init__(self, parent=None):
super(LongProcess, self).__init__(parent)
self.setup(self)
def setup(self, MainWindow):
MainWindow.setObjectName(_fromUtf8("MainWindow"))
MainWindow.resize(255, 208)
MainWindow.setMinimumSize(QtCore.QSize(300, 208))
MainWindow.setMaximumSize(QtCore.QSize(300, 208))
self.centralwidget = QtGui.QWidget(MainWindow)
self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
self.verticalLayout = QtGui.QVBoxLayout(self.centralwidget)
self.verticalLayout.setObjectName(_fromUtf8("verticalLayout"))
self.textEdit = QtGui.QTextEdit(self.centralwidget)
self.textEdit.setObjectName(_fromUtf8("textEdit"))
self.verticalLayout.addWidget(self.textEdit)
self.pushButton = QtGui.QPushButton(self.centralwidget)
self.pushButton.setObjectName(_fromUtf8("pushButton"))
self.verticalLayout.addWidget(self.pushButton)
MainWindow.setCentralWidget(self.centralwidget)
MainWindow.setWindowTitle(QtGui.QApplication.translate("MainWindow", "MainWindow", None, QtGui.QApplication.UnicodeUTF8))
self.textEdit.setHtml(QtGui.QApplication.translate("MainWindow", "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0//EN\" \"http://www.w3.org/TR/REC-html40/strict.dtd\">\n"
"<html><head><meta name=\"qrichtext\" content=\"1\" /><style type=\"text/css\">\n"
"p, li { white-space: pre-wrap; }\n"
"</style></head><body style=\" font-family:\'MS Shell Dlg 2\'; font-size:8.25pt; font-weight:400; font-style:normal;\">\n"
"<p style=\" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;\"><span style=\" font-size:8pt;\">We want to run a long process in the background (calling a subprocess) and use an oscillating progress bar to show that the process is running. </span></p>\n"
"<p style=\"-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; font-size:8pt;\">
</p>\n"
"<p style=\" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;\"><span style=\" font-size:8pt;\">When long process ends, we will close the oscillating progress bar. </span></p></body></html>", None, QtGui.QApplication.UnicodeUTF8))
self.pushButton.setText(QtGui.QApplication.translate("MainWindow", "Run Long Process", None, QtGui.QApplication.UnicodeUTF8))
QtCore.QMetaObject.connectSlotsByName(MainWindow)
@pyqtSignature("")
def on_pushButton_clicked(self):
'''
Simulate some long process to be performed.
Before Long Process starts, show an oscillating progress bar to
indiate process is running in background.
'''
dialog = QtGui.QDialog()
progressBar = Ui_porcessProgress()
progressBar.setupUi(dialog)
dialog.show()
# dialog.exec_()
start = time.time()
diff = 0
while diff < 10:
end = time.time()
diff = end - start
print (diff)
class Ui_porcessProgress(object):
def setupUi(self, porcessProgress):
porcessProgress.setObjectName(_fromUtf8("porcessProgress"))
porcessProgress.setWindowModality(QtCore.Qt.ApplicationModal)
porcessProgress.resize(329, 81)
porcessProgress.setMinimumSize(QtCore.QSize(329, 81))
porcessProgress.setMaximumSize(QtCore.QSize(329, 81))
icon = QtGui.QIcon()
icon.addPixmap(QtGui.QPixmap(_fromUtf8(":/WFT/wftlogo2.png")), QtGui.QIcon.Normal, QtGui.QIcon.Off)
porcessProgress.setWindowIcon(icon)
porcessProgress.setModal(True)
self.verticalLayout = QtGui.QVBoxLayout(porcessProgress)
self.verticalLayout.setObjectName(_fromUtf8("verticalLayout"))
self.label = QtGui.QLabel(porcessProgress)
self.label.setObjectName(_fromUtf8("label"))
self.verticalLayout.addWidget(self.label)
self.porcessProgressBar = QtGui.QProgressBar(porcessProgress)
self.porcessProgressBar.setMaximum(0)
self.porcessProgressBar.setProperty("value", 10)
self.porcessProgressBar.setTextVisible(False)
self.porcessProgressBar.setObjectName(_fromUtf8("porcessProgressBar"))
self.verticalLayout.addWidget(self.porcessProgressBar)
porcessProgress.setWindowTitle(QtGui.QApplication.translate("porcessProgress", "Please wait...", None, QtGui.QApplication.UnicodeUTF8))
self.label.setText(QtGui.QApplication.translate("porcessProgress", "Time History data extraction from ODB file in progress...", None, QtGui.QApplication.UnicodeUTF8))
QtCore.QMetaObject.connectSlotsByName(porcessProgress)
#
#------------------------------------------------------------------------------
#
def main():
app = QtGui.QApplication(sys.argv)
mainWindow = LongProcess()
mainWindow.show()
sys.exit(app.exec_())
#
#------------------------------------------------------------------------------
#
if __name__ == "__main__":
main()
4 回答
这有点解决这个问题的方法 .
如果你想以正确的方式做到这一点,你应该将while循环放在QThread中,并使用Signal和slot来更新QProgressbar .
但这会解决你现在的问题 .
丢失的部分是,
设置progressBar setMaximum(value) 的最大值
添加代码更新progressBar setValue(value)
使用 QApplication.processEvents() 强制执行事件处理
快速解决 :
您需要从按钮插槽返回以进行GUI更新 . 如果您坐在那个插槽中,那么您将阻止UI线程,因此不会显示实际(可见)小部件设置 .
我'm not familiar with Python, but the Qt way of running processes in the background (which won' t阻止你的UI)是使用QProcess . QProcess实例具有通知子进程状态更改的信号,以及处理输入和输出流的方法 . 您可能希望研究它,它将允许更多的灵活性 .
(特别是,你根本不需要处理线程,IMO,这是一件好事 . )
你在
on_pushButton_clicked
方法中所做的一切都将在gui线程中执行,因此冻结了gui . 只需将其移至QThread
. 和read this .通过主线程循环的ProgressBar将锁定运行GUI的同一个线程,因此您需要将执行长进程的部分线程化并报告回主线程 . Take a look at this SO question