PyQT:使用按钮添加到 QAbstractItemModel [英] PyQT: adding to QAbstractItemModel using a button

问题描述

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添加一个项目.

I'm trying to implement a TreeView using QAbstractItemModel. I want to set up an empty model and then add an item to the model using a button.

这似乎比我意识到的要复杂得多！我修改了 Lib\site-packages\PyQt4\examples\itemviews\simpletreemodel\simpletreemodel.pyw 中的 QAbstractItemModel 示例的自定义实例.

This appears to be a lot more complex than I'd realised! I've modified a custom instance of the QAbstractItemModel example found in the Lib\site-packages\PyQt4\examples\itemviews\simpletreemodel\simpletreemodel.pyw.

与其一次性设置所有模型，不如逐步构建.

Rather than setting up the model all at once, I want o build it incrementally.

当我单击按钮时，我收到消息，显示正在执行 process 方法，但模型未更新.

When I click the button, I get the message showing that the process method is executing, but the model isn't updated.

任何有关为什么它不起作用的提示将不胜感激！

Any pointers as to why it's not working would be greatly appreciated!

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_())

推荐答案

使用 QStandardItemModel 很有用！

Using a QStandardItemModel has worked a treat!

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_()

这篇关于PyQT:使用按钮添加到 QAbstractItemModel的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！