python - 选择目录后，QtGui.QFileDialog.getExistingDirectory() 窗口不会关闭(PyQt)

Question

我正在尝试在python程序中使用QtGui.QFileDialog.getExistingDirectory()对话框窗口获取路径，以简化用户的操作，而其余的则程序在控制台输出中。我有这段代码用于此目的:

import sys, os
from PyQt4 import QtGui

def getpath(filename,
            noPathFileMsg='',
            wrongFolderMsg='',
            selectFolderMsg=''):

    try:
        f = open('./'+filename,'r')
    except IOError:
        folder = get_new_path(filename,
                                     noPathFileMsg, 
                                     selectFolderMsg)
    else:
        folder = f.readline()
        f.close()
        currentDir = os.getcwd()
        try:
            os.chdir(folder)
        except:
            folder = get_new_path(filename,
                                         wrongFolderMsg,
                                         selectFolderMsg)
        else:
            os.chdir(currentDir)
    finally:
        return folder

def get_new_path(filename,
                 infoMsg,
                 selectFolderMsg):

    app = QtGui.QApplication(sys.argv)
    QtGui.QMessageBox.about(None, 'No folder', infoMsg)
    folder = QtGui.QFileDialog.getExistingDirectory(None, selectFolderMsg)
    app.exit()
    if os.name == 'posix':
        folder += '/'
    elif os.name == 'nt':
        folder += '\\'
    g = open('./'+filename,'w')
    g.write(folder)
    g.close()
    return folder
if __name__ == '__main__':
    folderPath = getpath('pathtofolder.txt',
                         noPathFileMsg='The path to the folder has not been set',
                         wrongFolderMsg='The path folder saved cannot be reached',
                         selectFolderMsg='Please select a folder')
    print folderPath
    var = input('The program stopped at the input instruction, the dialog window should now be closed!')

如果我调用 getpath 函数，对话框窗口将保持打开状态，直到调用该函数的脚本结束，而不是在此指令之后立即关闭:

folder = QtGui.QFileDialog.getExistingDirectory(None, selectFolderMsg)

如果运行此代码，它将创建一个文件，该文件将对话框窗口保存的目录保存在运行脚本的文件夹中。

我做错了什么？

顺便说一句，我使用的是 Ubuntu 12.04。谢谢你!干杯

Answer 1

在虚拟机中设置 Ubuntu 12.04 后，我可以确认单击“打开”后该对话框没有正确关闭。

该问题似乎是由于尝试退出 get_new_path 函数内的 QApplication 引起的。

相反，您应该创建一个全局 QApplication 对象，并且仅在脚本完成时退出它:

def get_new_path(filename, infoMsg, selectFolderMsg):

    QtGui.QMessageBox.about(None, 'No folder', infoMsg)
    folder = QtGui.QFileDialog.getExistingDirectory(None, selectFolderMsg)
    ...

if __name__ == '__main__':

    app = QtGui.QApplication(sys.argv)

    folderPath = getpath(...)

    app.exit()