在设置模块中使用python 2.7.6/PyQt4处理QVariants

Question

我以前在这个网站和其他平台上读过几个主题，但是我的代码仍然不能按需要工作。我似乎无法将所有拼图拼凑在一起，需要有人来查看我的代码。

我正在为程序QtiPlot编写一个插件。我使用Python 2.7.6和PyQt4。我使用QT Designer创建了插件GUI。我也是Python的新手。我使用这些“旧”资源，因为我的前任使用过它们。

我目前的任务是开发设置，即能够保存和恢复参数。 我在此网站上找到了一个用于此目的的模板：Python PyQt4 functions to save and restore UI widget values?

我想将参数保存到Ini文件中。 但是我有问题的QVariants。而不是我插入插件中的字符串，表达式“PyQt4.QtCore.QVariant对象在0x08667FB0”正在保存。我已经知道这是一个问题，因为QVariants没有被正确地转换回Python对象。因此，为了手动将QVariants转换回来，我在恢复功能中注释了QLineEdit-Objects的值赋值（注释掉的是以前的版本），我在短语“toString（）”中添加了“toString（）”这个词组。但是然后我的QLineEdit-Blocks插件是空的，这让我感到困惑。我在文档中读到，如果QVariant不包含预设类型之一（包括字符串），则返回空字符串。但是这种情况发生，虽然我之前输入了一个字符

这是否意味着字符串没有正确保存在第一位？否则它意味着什么，我错过了什么或者我做错了什么？

我也注意到没有值存储在Ini文件中，因此部分代码也是bug。但我不确定这是由于保存功能不起作用或因为Ini构造本身是错误的。

此外，我试图在配置文件的头部使用SIP模块来解决我的问题（它也被注释掉了，因为它到目前为止还不适用于我）。但是，尽管我把它放在代码的头部，但是我得到错误“API'QVariant'已经被设置为版本1”。我不明白为什么或从什么SIP指令被覆盖。有没有什么办法解决这一问题？

我的配置程序是这样的：

#import sip  
#sip.setapi('QVariant', 2)  
#sip.setapi('QString', 2) 

import inspect  
import sys 

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

sys.path.append("C:\\Program Files (x86)\\QtiPlot\\app\\02 Python Packages") 

import PyQt4_Save_Restore_UI_Widget_Values 

class app_conf(QtGui.QWidget): 

    def __init__(self): 

     super(self.__class__, self).__init__() 

     self.version = 1.0 

     QtCore.QCoreApplication.setOrganizationName("Organization") 
     QtCore.QCoreApplication.setApplicationName("Application") 
     QtCore.QSettings.setPath(QSettings.IniFormat, QSettings.UserScope, "C:\\Program Files (x86)\\QtiPlot\\app\\02 Python Packages\\saved.ini") 
     self.settings = QtCore.QSettings("C:\\Program Files (x86)\\QtiPlot\\app\\02 Python Packages\\saved.ini", QSettings.IniFormat) 

     from PyQt4 import uic 

     self.ui = uic.loadUi(r"C:\Program Files (x86)/QtiPlot/app/03 UI Files/Config.ui") 

     PyQt4_Save_Restore_UI_Widget_Values.gui_restore_settings(self.ui, self.settings) 

     self.ui.closeEvent = self.closeEvent 
     self.ui.show() 


    def closeEvent(self, event):    
     PyQt4_Save_Restore_UI_Widget_Values.gui_save_settings(self.ui, self.settings) 


window = app_conf() 

我的设置模块（PyQt4_Save_Restore_UI_Widget_Values.py）看起来是这样的：

#=================================================================== 
# Module with functions to save & restore qt widget values 
# Written by: Alan Lilly 
# Website: http://panofish.net 
#=================================================================== 

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


def gui_save_settings(ui, settings): 

    #for child in ui.children(): # works like getmembers, but because it traverses the hierarachy, you would have to call guisave recursively to traverse down the tree 

    for name, obj in inspect.getmembers(ui): 
     #if type(obj) is QComboBox: # this works similar to isinstance, but missed some field... not sure why? 
     if isinstance(obj, QComboBox): 
      name = obj.objectName()  # get combobox name 
      index = obj.currentIndex() # get current index from combobox 
      text = obj.itemText(index) # get the text for current index 
      settings.setValue(name, text) # save combobox selection to registry 

     if isinstance(obj, QLineEdit): 
      name = obj.objectName() 
      value = obj.text() 
      settings.setValue(name, value) # save ui values, so they can be restored next time 

     if isinstance(obj, QCheckBox): 
      name = obj.objectName() 
      state = obj.checkState() 
      settings.setValue(name, state) 


def gui_restore_settings(ui, settings): 

    for name, obj in inspect.getmembers(ui): 
     if isinstance(obj, QComboBox): 
      index = obj.currentIndex() # get current region from combobox 
      #text = obj.itemText(index) # get the text for new selected index 
      name = obj.objectName() 

      value = unicode(settings.value(name)) 

      if value == "": 
       continue 

      index = obj.findText(value) # get the corresponding index for specified string in combobox 

      if index == -1: # add to list if not found 
       obj.insertItems(0,[value]) 
       index = obj.findText(value) 
       obj.setCurrentIndex(index) 
      else: 
       obj.setCurrentIndex(index) # preselect a combobox value by index  

     if isinstance(obj, QLineEdit): 
      name = obj.objectName() 
      #value = unicode(settings.value(name)) # get stored value from registry 
      value = settings.value(name).toString() 
      obj.setText(value) # restore lineEditFile 

     if isinstance(obj, QCheckBox): 
      name = obj.objectName() 
      value = settings.value(name) # get stored value from registry 
      if value != None: 
       obj.setCheckState(value.toBool()) # restore checkbox 


################################################################ 

if __name__ == "__main__": 

    # execute when run directly, but not when called as a module. 
    # therefore this section allows for testing this module! 

    #print "running directly, not as a module!" 

    sys.exit() 

Answer 1

与在Python 2和SIP旧API中一样，toString()将返回QString。对于get和set方法，您必须强制它使用str的Python字符串。关于QCheckBox，我使用了toInt而不是toBool（这对我来说工作正常）。

这里是您的保存和恢复功能的修改后的版本：

def gui_save_settings(ui, settings): 

    for _, obj in inspect.getmembers(ui): 
     name = obj.objectName() 

     # Set QComboBox setting 
     if isinstance(obj, QComboBox): 
      value = str(obj.currentText()) # get current text from combobox 
      settings.setValue(name, value) # save combobox selection to registry 

     # Set QLineEdit setting 
     if isinstance(obj, QLineEdit): 
      value = str(obj.text()) 
      settings.setValue(name, value) # save ui values, so they can be restored next time 

     # Set QCheckBox setting 
     if isinstance(obj, QCheckBox): 
      value = int(checkbox.isChecked()) 
      settings.setValue(name, value) 

def gui_restore_settings(ui, settings): 

    for _, obj in inspect.getmembers(ui): 
     name = obj.objectName() 

     # Get QComboBox setting 
     if isinstance(obj, QComboBox): 
      value = str(settings.value(name).toString()) 
      if value == "": 
       continue 

      index = obj.findText(value) # get the corresponding index for specified string in combobox 

      if index == -1: # add to list if not found 
       obj.addItem(value) 
       index = obj.findText(value) 

      obj.setCurrentIndex(index) # preselect a combobox value by index 
      continue 

     # Get QLineEdit setting 
     if isinstance(obj, QLineEdit): 
      value = str(settings.value(name).toString()) 
      obj.setText(value) # restore lineEditFile 
      continue 

     # Get QCheckBox setting 
     if isinstance(obj, QCheckBox): 
      value, res = settings.value(key).toInt() # get stored value from registry 
      if res: 
       obj.setCheckState(value) # restore checkbox 
      continue 

Answer 2

最好的解决方案是使用sip.setapi。但为了使它正常工作，它必须在您的应用程序中导入PyQt之前调用必须之前的第一个。因此，它需要在主脚本中去，而不是配置模块：

#=================================================================== 
# Module with functions to save & restore qt widget values 
# Written by: Alan Lilly 
# Website: http://panofish.net 
#=================================================================== 
import sys 
import sip 
sip.setapi('QVariant', 2)  
sip.setapi('QString', 2) 
from PyQt4.QtCore import * 
from PyQt4.QtGui import * 
import inspect 

这将确保QVariant和QString总是自动转换为普通Python类型 - 因此没有必要使用unicode()，toString()，toBool()等。