PyQT：使用按钮添加到 QAbstractItemModel

Question

我正在尝试使用 QAbstractItemModel 实现 TreeView。我想设置一个空模型，然后使用按钮向模型中添加一个项目。

这似乎比我想象的要复杂得多！我已经修改了 Lib\site-packages\PyQt4\examples\itemviews\simpletreemodel\simpletreemodel.pyw 中的 QAbstractItemModel 示例的自定义实例。

我不想一次性设置模型，而是逐步构建它。

当我单击按钮时，我收到一条消息，显示流程方法正在执行，但模型没有更新。

任何关于它为什么不工作的指针将不胜感激！

from PyQt4 import QtGui, QtCore
import sys

class myWindow(QtGui.QWidget):
    def __init__(self):
        QtGui.QWidget.__init__(self)
        self.resize(500, 400)

        #Tree Widget
        self.treeView = QtGui.QTreeView(self)

        #Model
        self.model = TreeModel()                    
        self.treeView.setModel(self.model)

        # Button
        self.button = QtGui.QPushButton(self)
        self.button.setText('Add Item')    
        self.button.clicked.connect(self.process)

        # Add to Layout    
        self.gridLayout = QtGui.QGridLayout(self)
        self.gridLayout.addWidget(self.button,0,0)
        self.gridLayout.addWidget(self.treeView,1,0)

     def process(self):
        print "here"        
        newItem = TreeItem(["bob","bob","bob"],self.model.rootItem)       
        self.model.rootItem.appendChild(newItem) 

class TreeItem(object):
    def __init__(self, data, parent=None):
        self.parentItem = parent
        self.itemData = data
        self.childItems = []

    def appendChild(self, item):
        self.childItems.append(item)

    def child(self, row):
        return self.childItems[row]

    def childCount(self):
        return len(self.childItems)

    def columnCount(self):
        return len(self.itemData)

    def data(self, column):
        try:
            return self.itemData[column]
        except IndexError:
            return None

    def parent(self):
        return self.parentItem

    def row(self):
        if self.parentItem:
            return self.parentItem.childItems.index(self)
        return 0

class TreeModel(QtCore.QAbstractItemModel):
    def __init__(self, parent=None):
        super(TreeModel, self).__init__(parent)
        self.rootItem = TreeItem(("Model", "Status","Location"))

    def columnCount(self, parent):
        if parent.isValid():
            return parent.internalPointer().columnCount()
        else:
            return self.rootItem.columnCount()

    def data(self, index, role):
        if not index.isValid():
            return None

        if role != QtCore.Qt.DisplayRole:
            return None

        item = index.internalPointer()

        return item.data(index.column())

    def flags(self, index):
        if not index.isValid():
            return QtCore.Qt.NoItemFlags

        return QtCore.Qt.ItemIsEnabled | QtCore.Qt.ItemIsSelectable

    def headerData(self, section, orientation, role):
        if orientation == QtCore.Qt.Horizontal and role == QtCore.Qt.DisplayRole:
            return self.rootItem.data(section)

        return None

    def index(self, row, column, parent):
        if not self.hasIndex(row, column, parent):
            return QtCore.QModelIndex()

        if not parent.isValid():
            parentItem = self.rootItem
        else:
            parentItem = parent.internalPointer()

        childItem = parentItem.child(row)
        if childItem:
            return self.createIndex(row, column, childItem)
        else:
            return QtCore.QModelIndex()

    def parent(self, index):
        if not index.isValid():
            return QtCore.QModelIndex()

        childItem = index.internalPointer()
        parentItem = childItem.parent()

        if parentItem == self.rootItem:
            return QtCore.QModelIndex()

        return self.createIndex(parentItem.row(), 0, parentItem)

    def rowCount(self, parent):
        if parent.column() > 0:
            return 0

        if not parent.isValid():
            parentItem = self.rootItem
        else:
            parentItem = parent.internalPointer()

        return parentItem.childCount()

if __name__ == "__main__":
    app = QtGui.QApplication.instance() # checks if QApplication already exists 
    if not app: # create QApplication if it doesnt exist 
        app = QtGui.QApplication(sys.argv)
    # Window
    window = myWindow()                    
    window.show()
    sys.exit(app.exec_())

Answer 1

使用 QStandardItemModel 是一种享受！

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *

class Window(QWidget):
    def __init__(self):
        QWidget.__init__(self)
        self.resize(500, 400)

        #Tree Widget
        self.treeView = QTreeView()        

        #Model        
        self.model = QStandardItemModel()
        self.treeView.setModel(self.model)

        # Button
        self.button = QPushButton()
        self.button.setText('Add Item')    
        self.button.clicked.connect(self.addChildClick)

        # Add to Layout    
        self.gridLayout = QGridLayout(self)
        self.gridLayout.addWidget(self.button,0,0)
        self.gridLayout.addWidget(self.treeView,1,0)

    def addChildClick(self):        
        selection = self.treeView.selectedIndexes() 
        text = "bob"
        item = QStandardItem(text)

        # if nothing selected parent is model        
        if selection == []:        
            parent = self.model

        else: # Otherwise parent is what is selected
            s = selection[0] # Handling multiple selectons            
            parent = self.model.itemFromIndex(s)

        parent.appendRow(item)

        #cleanup        
        self.treeView.expandAll()
        self.treeView.clearSelection()

if __name__ == "__main__":
    app = QApplication.instance() # checks if QApplication already exists 
    if not app: # create QApplication if it doesnt exist 
        app = QApplication(sys.argv)

    # Window
    window = Window()                    
    window.show()
    app.exec_()