如何实现自定义QAbstractItemModel类
时间: 2023-12-14 12:37:28 浏览: 77
要实现自定义的QAbstractItemModel类,需要继承QAbstractItemModel类并实现其虚函数。下面是一个示例:
```python
from PyQt5.QtCore import QAbstractItemModel, QModelIndex, Qt
class MyModel(QAbstractItemModel):
def __init__(self, data, parent=None):
super().__init__(parent)
self.rootNode = Node(None, "Root")
self.setupModel(data.split('\n'), self.rootNode)
def setupModel(self, lines, parentNode):
parents = [parentNode]
indentations = [0]
for line in lines:
strippedLine = line.strip()
indentation = line.count('\t')
strippedLine = strippedLine.replace('\t', '')
if not strippedLine:
continue
node = Node(parents[-1], strippedLine)
if indentation > indentations[-1]:
parents.append(parents[-1].child(parents[-1].childCount() - 1))
indentations.append(indentation)
elif indentation < indentations[-1]:
while indentation < indentations[-1] and len(parents) > 0:
parents.pop()
indentations.pop()
parents[-1].appendChild(node)
def index(self, row, column, parent=QModelIndex()):
if not self.hasIndex(row, column, parent):
return QModelIndex()
if not parent.isValid():
parentNode = self.rootNode
else:
parentNode = parent.internalPointer()
childNode = parentNode.child(row)
if childNode:
return self.createIndex(row, column, childNode)
else:
return QModelIndex()
def parent(self, index):
if not index.isValid():
return QModelIndex()
childNode = index.internalPointer()
parentNode = childNode.parent()
if parentNode == self.rootNode:
return QModelIndex()
return self.createIndex(parentNode.row(), 0, parentNode)
def rowCount(self, parent=QModelIndex()):
if parent.column() > 0:
return 0
if not parent.isValid():
parentNode = self.rootNode
else:
parentNode = parent.internalPointer()
return parentNode.childCount()
def columnCount(self, parent=QModelIndex()):
return 1
def data(self, index, role):
if not index.isValid():
return None
node = index.internalPointer()
if role == Qt.DisplayRole or role == Qt.EditRole:
return node.name()
return None
class Node(object):
def __init__(self, parent, name):
self._name = name
self._parent = parent
self._children = []
if parent is not None:
parent.appendChild(self)
def appendChild(self, child):
self._children.append(child)
def child(self, row):
return self._children[row]
def childCount(self):
return len(self._children)
def parent(self):
return self._parent
def row(self):
if self._parent is not None:
return self._parent._children.index(self)
return 0
def name(self):
return self._name
```
在这个示例中,我们实现了一个树形模型,用于显示一个包含缩进的文本文件。在构造函数中,我们调用了`setupModel`方法来设置节点和它们的父子关系。`index`、`parent`、`rowCount`、`columnCount`和`data`是QAbstractItemModel类中的虚函数,我们在自定义的MyModel类中实现这些函数。我们还实现了一个Node类来表示节点,它包含节点的名称、父节点和子节点。