【转载】 Pyqt 利用QDataStream对文件进行存取

 # -*- coding: utf-8 -*-
 from PyQt4.QtGui import *
 from PyQt4.QtCore import *
 import sys
 QTextCodec.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_()