【PyQt4 实例29】利用QDataStream对文件进行存取

# -*- coding: utf-8 -*-from PyQt4.QtGui import *from PyQt4.QtCore import *import sysQTextCodec.setCodecForTr(QTextCodec.codecForName("utf8"))class Settings(QDialog):    def __init__(self,parent=None):        super(Settings,self).__init__(parent)        self.setWindowTitle(self.tr("利用QDataStream对文件进行存取"))                self.label = QLabel(self.tr("通道："))        self.channelSpinBox = QSpinBox()        self.channelSpinBox.setRange(0,20)        self.timeLabel = QLabel(self.tr("第一次运行"))                self.label_gong =QLabel(self.tr("功率："))        self.powerComboBox = QComboBox()        self.powerComboBox.addItem(self.tr("大"),"大")        self.powerComboBox.addItem(self.tr("中"),"中")        self.powerComboBox.addItem(self.tr("小"),"小")        self.saveButton = QPushButton(self.tr("保存"))                self.label_Frequency = QLabel(self.tr("频率："))        self.FrequencyEdit = QLineEdit()        self.getButton = QPushButton(self.tr("读取"))                layout = QGridLayout(self)        layout.addWidget(self.label,0,0)        layout.addWidget(self.channelSpinBox,0,1)        layout.addWidget(self.timeLabel,0,2)                layout.addWidget(self.label_gong,1,0)        layout.addWidget(self.powerComboBox,1,1)        layout.addWidget(self.saveButton,1,2)                layout.addWidget(self.label_Frequency,2,0)        layout.addWidget(self.FrequencyEdit,2,1)        layout.addWidget(self.getButton,2,2)                self.resize(250,150)                self.connect(self.saveButton,SIGNAL("clicked()"),self.slotSave)        self.connect(self.getButton,SIGNAL("clicked()"),self.slotGet)             def slotSave(self):        self.channel = self.channelSpinBox.value()        self.power = self.powerComboBox.currentIndex()        self.frequency = self.FrequencyEdit.text()        self.time = QDateTime()        file = QFile("parameters.dat")        file.open(QIODevice.WriteOnly)        out = QDataStream(file)        out.setVersion(QDataStream.Qt_4_0)                out.writeUInt32(0xa1a2a3a4)        out.writeUInt32(self.channel)        out.writeUInt32(self.power)        out.writeString(self.frequency)        out << self.time.currentDateTime()                def slotGet(self):        file = QFile("parameters.dat")        file.open(QIODevice.ReadOnly)        In = QDataStream(file)        In.setVersion(QDataStream.Qt_4_0)        magic = In.readUInt32()        if magic != 0xa1a2a3a4:            QMessageBox.information(self,"exception",self.tr("invalid file format"))            return        channel = In.readUInt32()        power = In.readUInt32()        frequency = In.readString()         time = QDateTime()        In >> time        self.channelSpinBox.setValue(channel)        self.powerComboBox.setCurrentIndex(power)        self.FrequencyEdit.setText(frequency)        lastTime = time.date().toString(Qt.ISODate) + " " + time.time().toString()        self.timeLabel.setText(lastTime)        app=QApplication(sys.argv)dialog=Settings()dialog.show()app.exec_()