Python pyQt MVC - 将对象传递给模型类

Question

1. How is it that self.model = MyTableModel(self, [User('Mary', '12345'), User('John', 'qwerty')], ['name', 'password']) can pass object instance User('Mary', '12345') to MyTableModel() when I don't see def __init__(self, parent, rows, columns) set up to take it? From what I know, rows and columns are arguments to take info from the widget object and not a outside non widget object.

2. What does the last part ['name', 'password'] do when given to MyTableModel()?

3. Actually, I want just one instance of User() and have the model class update User() object instance if the human changes the lineEdit widget. since "mary" and "12345" in self.model = MyTableModel(self, [User('Mary', '12345')] are hardcoded values, how do I use the values of the lineEdit widgets instead in User(parameter, parameter)?

   from PyQt4 import QtCore, QtGui
   import sys
   
   class User():
       def __init__(self, name, password):
           self.name = name
           self.password = password
   
   
   class MyTableModel(QtCore.QAbstractTableModel):
   
       def __init__(self, parent, rows, columns):
           super().__init__(parent)
           self.rows = rows
           self.columns = columns
   
       def columnCount(self, index):
           return len(self.columns)
   
       def rowCount(self, index):
           return len(self.rows)
   
       def data(self, index, role):
           if index.isValid():
               if (role == QtCore.Qt.DisplayRole) or (role == QtCore.Qt.EditRole):
                   attr_name = self.columns[index.column()]
                   row = self.rows[index.row()]
                   return getattr(row, attr_name)
   
       def flags(self, index):
           if not index.isValid():
               return QtCore.Qt.ItemIsEnabled
           else:
               return QtCore.Qt.ItemIsEnabled | QtCore.Qt.ItemIsSelectable | QtCore.Qt.ItemIsEditable
   
       def setData(self, index, value, role=QtCore.Qt.EditRole):
           if index.isValid() and role == QtCore.Qt.EditRole:
               attr_name = self.columns[index.column()]
               row = self.rows[index.row()]
               setattr(row, attr_name, value)
   
   
   class MyWindow(QtGui.QWidget):
       def __init__(self):
           super(MyWindow, self).__init__()
           self.setLayout(QtGui.QFormLayout(self))
           self.user_edit = QtGui.QLineEdit(self)
           self.password_edit = QtGui.QLineEdit(self)
           self.mapper = QtGui.QDataWidgetMapper(self)
           self.model = MyTableModel(self, [User('Mary', '12345'), User('John', 'qwerty')], ['name', 'password'])
           self.mapper.setModel(self.model)
           self.mapper.addMapping(self.user_edit, 0)
           self.mapper.addMapping(self.password_edit, 1)
           self.mapper.toFirst()
   
           self.layout().addRow("User name:", self.user_edit)
           self.layout().addRow("Password:", self.password_edit)
   
           self.btnPrevious = QtGui.QPushButton("Previous", self)
           self.btnNext = QtGui.QPushButton("Next",self)
           self.layout().addWidget(self.btnPrevious)
           self.layout().addWidget(self.btnNext)
   
           self.btnPrevious.clicked.connect(self.mapper.toPrevious)
           self.btnNext.clicked.connect(self.mapper.toNext)
   
   if __name__ == "__main__":
       app = QtGui.QApplication(sys.argv)
       win = MyWindow()
       win.show()
       app.exec_()
   

- dman

Answer 1

1. 当我看不到def __init__(self, parent, rows, columns)设置来接收对象实例User('Mary', '12345')时，为什么self.model = MyTableModel(self, [User('Mary', '12345'), User('John', 'qwerty')], ['name', 'password'])可以将其传递给MyTableModel()？据我所知，行和列是从小部件对象中获取信息的参数，而不是外部非小部件对象。

这里的参数并不代表Qt-MVC意义上的行和列。相反，行应该是一个对象列表，而列应该是一个字符串列表，表示应该由模型实例展示的传递对象（在行参数中）的属性。

1. 当传递给MyTableModel()时，最后一部分['name', 'password']是做什么用的？

MyTableModel使用它来知道应该使用哪些对象属性进行显示。

实际上，我只想要一个User()的实例，并且在人类更改lineEdit小部件时，让模型类更新User()对象实例。由于self.model = MyTableModel(self, [User('Mary', '12345')])中的"mary"和"12345"是硬编码值，我该如何使用lineEdit小部件的值来代替User(parameter, parameter)中的值？

如果您的模型正确实现了setData协议并为模型中的所有项目返回ItemIsEditable，则用户已经可以更改模型内部的值（或使用该模型的视图）。您不需要额外的输入或更改GUI来完成此操作。

（如果您只想知道如何获取QLineEdit的当前文本内容，那么可以使用text()方法）

- dom0