Question

我已经创建了一个自定义输出流，并且在它的帮助下我将输出重定向到python QT TextEdit，但是在文本编辑中它显示了重定向的所有输出，我想知道是否有某种方式显示一次只有最后一行。例如，它显示从1到99的for循环数据。文本编辑显示从1到99的所有迭代的数据。我希望它应该只显示最后一行，即可能是2然后是3而儿子则是99。

请参阅以下示例代码：

import sys
import os
from PyQt4 import QtGui,QtCore
from threading import Thread


class EmittingStream(QtCore.QObject):

    textWritten = QtCore.pyqtSignal(str)

    def write(self, text):
        self.textWritten.emit(str(text))

class gui(QtGui.QMainWindow):

    def __init__(self):
    # ...
        super(gui, self).__init__()
    # Install the custom output stream
        sys.stdout = EmittingStream(textWritten=self.normalOutputWritten)
        self.initUI()

    def __del__(self):
        # Restore sys.stdout
        sys.stdout = sys.__stdout__


    def normalOutputWritten(self, text):
        cursor = self.textEdit.textCursor()
        cursor.movePosition(QtGui.QTextCursor.End)
        cursor.insertText(text)
        self.textEdit.ensureCursorVisible()

    def callProgram(self):
        for i in range(1,100):
            command="echo hi %s"%i
            result=os.popen(str(command)).read()
            print result


    def initUI(self):
        self.setGeometry(100,100,300,300)
        self.show()

        cmd=QtGui.QButtonGroup(self)
        self.NoCmd=QtGui.QRadioButton("Best Quality",self)
        self.NoCmd.setChecked(True)
        self.runCommand = QtGui.QRadioButton("Quality Options",self)
        cmd.addButton(self.NoCmd)
        cmd.addButton(self.runCommand)
        self.lineEdit=QtGui.QLineEdit(self)

        self.textEdit=QtGui.QTextEdit(self)
        self.textEdit.show()
        self.textEdit.setGeometry(20,40,200,200)
        self.lineEdit.move(200,0)
        self.runCommand.move(100,0)

        self.lineEdit.show()
        self.NoCmd.show()
        self.runCommand.show()
        print "changing sys.out"
        print "hello"

        thread = Thread(target = self.callProgram)
        thread.start()


#Function Main Start
def main():
    app = QtGui.QApplication(sys.argv)
    ui=gui()
    sys.exit(app.exec_())
#Function Main END

if __name__ == '__main__':
    main()

提前致谢

Answer 1

每次数字行超过某个限制时，您都可以删除文本编辑的第一行：

    def normalOutputWritten(self, text):
        cursor = self.textEdit.textCursor()
        cursor.movePosition(QtGui.QTextCursor.End)
        cursor.insertText(text)
        # show only the last 10 lines
        if self.textEdit.document().lineCount() > 10:
            cursor.movePosition(QtGui.QTextCursor.Start)
            cursor.select(QtGui.QTextCursor.LineUnderCursor)
            cursor.removeSelectedText()
            cursor.deleteChar()
        self.textEdit.ensureCursorVisible()

Python在pyQt Widget中重定向并仅显示最后一行

1 个答案: