使用 QFileSystemModel 时索引 PyQt5 组合框

Question

我需要从文件的目录列表中选择出现在组合框中的默认文件。使用普通的组合框，很容易使用 .findText 找到您想要的值的索引，但这似乎不适用于 QFileSystemModel 组合框，可能是由于在目录列表可以之前不会填充选项列表的方式获得资源。

这是我尝试过的：

import sys
import collections
from PyQt5 import QtCore, QtWidgets
from PyQt5.QtWidgets import QMainWindow, QLabel, QGridLayout, QWidget, QComboBox
from PyQt5.QtCore import QSize, QRect    

class ComboWindow(QMainWindow):
    def __init__(self):
        QMainWindow.__init__(self)

        self.setMinimumSize(QSize(640, 140))    
        self.setWindowTitle("Combobox example") 

        centralWidget = QWidget(self)          
        self.setCentralWidget(centralWidget)   

        # Create combobox and add items.
        self.fsm = QtWidgets.QFileSystemModel()        
        self.fsm.setNameFilters(["*.txt"]) 
        self.configComboBox = QtWidgets.QComboBox(self)
        self.configComboBox.setGeometry(QRect(40, 40, 491, 31))
        self.configComboBox.setObjectName(("comboBox"))
        self.configComboBox.setModel(self.fsm)                
        self.fsm.setFilter(QtCore.QDir.NoDotAndDotDot | QtCore.QDir.Files)        
        # "text_files" is a subdir of current dir with files 
        # example1.txt, example2.txt, example3.txt
        self.configComboBox.setRootModelIndex(self.fsm.setRootPath("text_files")) 
        # V V This section does not work V V
        index = self.configComboBox.findText(MainConfig.settings["default_txt_file"])
        self.configComboBox.setCurrentIndex(index)

class MainConfig:
    settings = collections.OrderedDict()  

    @staticmethod
    def createDefaultConfig(name):
        MainConfig.settings["default_txt_file"] = "example3.txt"     

if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    mainWin = ComboWindow()
    mainWin.show()
    sys.exit( app.exec_() )

Answer 1

正如我在this answer 中指出的那样，QFileSystemModel 在新线程中异步加载，因此您必须使用 directoryLoaded 信号来了解信息何时完成加载：

import collections
import os
import sys

from PyQt5.QtWidgets import (
    QApplication,
    QComboBox,
    QFileSystemModel,
    QMainWindow,
    QWidget,
)
from PyQt5.QtCore import pyqtSlot, QDir, QRect, QSize


class ComboWindow(QMainWindow):
    def __init__(self, parent=None):
        super(ComboWindow, self).__init__(parent=None)

        self.setMinimumSize(QSize(640, 140))
        self.setWindowTitle("Combobox example")

        centralWidget = QWidget(self)
        self.setCentralWidget(centralWidget)

        # Create combobox and add items.
        self.fsm = QFileSystemModel()
        self.fsm.setNameFilters(["*.txt"])
        self.configComboBox = QComboBox(self)
        self.configComboBox.setGeometry(QRect(40, 40, 491, 31))
        self.configComboBox.setObjectName(("comboBox"))
        self.configComboBox.setModel(self.fsm)
        self.fsm.setFilter(QDir.NoDotAndDotDot | QDir.Files)
        self.fsm.directoryLoaded.connect(self.on_directoryLoaded)
        current_dir = os.path.dirname(os.path.realpath(__file__))
        dir_path = os.path.join(current_dir, "text_files")
        self.configComboBox.setRootModelIndex(self.fsm.setRootPath(dir_path))

    @pyqtSlot(str)
    def on_directoryLoaded(self, path):
        index = self.configComboBox.findText(MainConfig.settings["default_txt_file"])
        self.configComboBox.setCurrentIndex(index)


class MainConfig:
    settings = collections.OrderedDict()

    @staticmethod
    def createDefaultConfig(name):
        MainConfig.settings["default_txt_file"] = name


if __name__ == "__main__":
    MainConfig.createDefaultConfig("example3.txt")
    app = QApplication(sys.argv)
    mainWin = ComboWindow()
    mainWin.show()
    sys.exit(app.exec_())