subclass

问题 I'm trying to create a text editor that will manipulate a string like object. Ideally I would like to subclass Tkinter's Text Widget or some other Gui module to allow me to substitute this custom object instead of using strings. I understand how to create the object itself (which essentially just tags every word with meta-data), but not how to manipulate the rendered object as text while retaining its other attributes. Eg. The text editor imports a file that contains "Hello World". Upon

问题 I'm trying to serialize a subclass of Path2D.Double, the serialization works, but the deserialization doesn't because of the following Exception: Exception in thread "main" java.io.InvalidClassException: CustomShape; no valid constructor at java.io.ObjectStreamClass$ExceptionInfo.newInvalidClassException(ObjectStreamClass.java:147) at java.io.ObjectStreamClass.checkDeserialize(ObjectStreamClass.java:755) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1751) at java.io

问题 Subclass sstr of the standard str type that implements the "<<" and ">>" methods as a cyclic shifting of the characters in the string.What trying to do is >>> s1 = sstr("abcde") >>> s1 << 0 'abcde' >>> s1 >> 0 'abcde' >>> s1 << 2 'cdeab' >>> s1 >> 2 'deabc' >>> s1 >> 5 'abcde' # my attempt: import string class sstr(str): def __new__(self, other): return str.__new__(self, other.upper()) def __ilshift__(self, other): return str.__ilshift(other) def __rshift__(self, other): return str.__rshift

问题 I'm going to create a base class that implements very similar functions for all of the subclasses. This was answered in a different question. But what I need to know now is if/how I can cast various functions (in the base class) to return the subclass object. This is both for a given function but also a function call in it. (I'm working with CoreData by the way) As a function within the base class (this is from a class that is going to become my subclass) +(Structure *)fetchStructureByID:

问题 I am trying to implement an auto-suggest feature in an win32 combobox (C++). I want to achieve a behaviour that is similar to the google auto suggest function. When the user types something into the edit-control of the combobox, its listbox opens and shows all possible matches. The Problem is the default behaviour of a win32 combobox is to always select the closest match and put the complete text (selected) into the edit control when the list is opened. I need to avoid this behaviour. The

问题 Hallo all. I have this set of classes: @Entity @Table(name = "S_MC_CC_RAPPORTI") @Inheritance(strategy=InheritanceType.JOINED) @DiscriminatorColumn(name="COD_TIPORAPPORTO", discriminatorType=DiscriminatorType.CHAR, length=1) public abstract class Rapporto implements Serializable { private static final long serialVersionUID = -5567166522882040440L; @Id @Column(name = "COD_RAPPORTO") protected Long codiceRapporto; And this sublass: @Entity @Table(name="S_MC_CC_CCCLIENTI") @DiscriminatorValue("1

问题 I want to show SQL data from a local db-File in a QML-Tableview and than would like to do some edits to the sql-database. What I managed to do after about three weeks: Showing my data in a QML-Tableview. I am not sure if I really need to subclass QSqlTableModel and I definitly would be glad if subclassing would not be neccessary at all. In my main.cpp following should create my model and directly add a record. // Create an instance of the SqlModel for accessing the data SqlDataModel *sqlModel

问题 I have to join a entity with a view to retrieve some data into properties <join table="XXVIEW" optional="true"> <key column="ID_ENT" /> <property name="Prop1" insert ="false" update ="false" /> <property name="Prop2" insert ="false" update ="false" /> <property name="Prop3" insert ="false" update ="false" /> </join> But when i try to save (insert) it fails becouse it try to insert a record in XXVIEW with ID_Ent I need to have some properties in this entity get from various calculations or

问题 My question is will the init method of list class calling other method such as append or insert to achieve its functionality. like: class test(list): def __init__(self,values): super().__init__() def append(self, value): self.append(value + 1) I want: x = test([1,2,3]) x [2,3,4] but I got: [1,2,3] I know I can make it work by overload init itself. def __init__(self,values): super().__init__([x+1 for x in values]) Can I just overload some basic value insert method like setitem , so all the

问题 My question is will the init method of list class calling other method such as append or insert to achieve its functionality. like: class test(list): def __init__(self,values): super().__init__() def append(self, value): self.append(value + 1) I want: x = test([1,2,3]) x [2,3,4] but I got: [1,2,3] I know I can make it work by overload init itself. def __init__(self,values): super().__init__([x+1 for x in values]) Can I just overload some basic value insert method like setitem , so all the