python - 使用 QFileSystemModel 时索引 PyQt5 组合框

Question

我需要从文件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 找到所需值的索引，但这似乎不适用于 QFileSystemModel 组合框，可能是因为选项列表在目录列表可以填充之前不会填充。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信号来知道信息何时完成加载:

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_())