我有 3 个和connect function与和pyQt相关3 signal:one slotone widget
    QtCore.QObject.connect(self.tableWidget, QtCore.SIGNAL(_fromUtf8("itemClicked(QTableWidgetItem*)")),
                           lambda:  self.materialsInstance.setFilterDict_Insert("TW",self,"imported_party_attributes",0,self.tableWidget.currentItem().row(),self.tableWidget.currentItem().column()))
    QtCore.QObject.connect(self.tableWidget, QtCore.SIGNAL(_fromUtf8("cellChanged(int,int)")),
                           lambda: self.materialsInstance.setFilterDict_Insert("TW",self,"imported_party_attributes",0,self.tableWidget.currentItem().row(),self.tableWidget.currentItem().column()))
    ###clear cell and remove from dict
    QtCore.QObject.connect(self.tableWidget, QtCore.SIGNAL(_fromUtf8("currentCellChanged(int,int,int,int)")),
                           lambda: self.materialsInstance.setFilterDict_Insert("TW",self,"imported_party_attributes",0,self.tableWidget.currentItem().row(),self.tableWidget.currentItem().column()))#,"currentCellChanged(int,int,int,int))"))
我对 2 first 没有任何问题connect function,但是我得到了以下 3th 的回溯connect function:
Traceback (most recent call last):
  File "/home/mohsen/codes/amlak/amlak/src/materialsInsertFrame.py", line 244, in <lambda>
    lambda: self.materialsInstance.setFilterDict_Insert("TW",self,"imported_party_attributes",0,self.tableWidget.currentItem().row(),self.tableWidget.currentItem().column()))#,"currentCellChanged(int,int,int,int))"))
AttributeError: 'NoneType' object has no attribute 'row'
我没有任何想法Signal-Sloting,你有吗?
注意: 2首先connect functions  工作正常。
我的问题signal是,前 2和最后有什么区别signal?