overriding

问题 I have this Class: namespace JimWcfFormTest3 { [DataContract] public class GateInfo { [DataMember] public int carid { get; set; } [DataMember] public int paid_at_gate { get; set; } [DataMember] public int wash_pkg_purch { get; set; } [DataMember] public string carte { get; set; } public override string ToString() { return "Car ID: " + carid + "Paid at Gate: " + paid_at_gate + "Wash Package: " + wash_pkg_purch + "Ala Carte: " + carte; } } } That is called by this WCF Service: namespace

问题 I'm trying to override the getListCellRendererComponent method in the DefaultListCellRenderer class in a scala class (I'm using the intellij scala plugin). Here's the code below: val cellRenderer = new javax.swing.DefaultListCellRenderer { override def getListCellRendererComponent(list: JList[_], value: AnyRef, index: Int, isSelected: Boolean, cellHasFocus: Boolean): Component = { val retval: JLabel = super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus)

问题 This question already has answers here : Is there a way to override class variables in Java? (17 answers) Closed 3 years ago . In Java, I have had several projects recently where I used a design pattern like this: public abstract class A { public abstract int getProperty(); } public class B extends A { private static final int PROPERTY = 5; @Override public int getProperty() { return PROPERTY; } } Then I can call the abstract method getProperty() on any member of class A . However, this seems

问题 I have a class: public abstract class AbstractDictionaryObject { public virtual int LangId { get; set; } public override bool Equals(object obj) { if (obj == null || obj.GetType() != GetType()) { return false; } AbstractDictionaryObject other = (AbstractDictionaryObject)obj; if (other.LangId != LangId) { return false; } return true; } public override int GetHashCode() { int hashCode = 0; hashCode = 19 * hashCode + LangId.GetHashCode(); return hashCode; } And I have derived classes: public

问题 Say i have this part of code: #include<iostream> using namespace std; class A { public: virtual int f(const A& other) const { return 1; } }; class B : public A { public: int f(const A& other) const { return 2; } virtual int f(const B& other) const { return 3; } }; void go(const A& a, const A& a1, const B& b) { cout << a1.f(a) << endl; //Prints 2 cout << a1.f(a1) << endl; //Prints 2 cout << a1.f(b) << endl; //Prints 2 } int main() { go(A(), B(), B()); system("pause"); return 0; } I can

问题 I have two classes: class A { public: int i; }; class B : public A { public: int i; }; Suppose that I created an object for class B B b; Is it possible to access A::i using b ? 回答1: Is it possible to access A::i using b? Yes! How about b.A::i ? ;) 回答2: Yes: int main() { B b; b.i = 3; b.A::i = 5; A *pA = &b; B *pB = &b; std::cout << pA->i << std::endl; std::cout << pB->i << std::endl; } 回答3: Yes you can. To find out read this An override method provides a new implementation of a member

问题 My question comes from a project. So let me abstract away a bit unrelated details. I have a JAVA public class A that has two protected static methods, foo() and bar(). The method foo() calls bar() in its body. public class A{ protected static foo(){ ... bar() ... } protected static bar(){print("A.bar()");} } Now I also have a class B extending A. In B, I override bar() class B extends A{ @Overrides static protected bar(){ print("A.bar() extended"); } Finally, I call foo() from a class in B

问题 In the following code I got the following compilation errors: 1>c:\users\mittamani\desktop\06-10\over_riding_test\over_riding_test\over_riding_test.cpp(33) : error C2555: '_D1::fun': overriding virtual function return type differs and is not covariant from 'Base2::fun' 1> c:\users\mittamani\desktop\06-10\over_riding_test\over_riding_test\over_riding_test.cpp(28) : see declaration of 'Base2::fun' 1> 'Base1' : base class is not accessible 1>c:\users\mittamani\desktop\06-10\over_riding_test\over

问题 How can you explain this: This code is supposed to override the NameError and then catch it. OldNameError = NameError class NameError(OldNameError): pass try: ccc except NameError as e: print "hi" Does not print "hi". Instead, the output is: Traceback (most recent call last): File "try.py", line 6, in <module> ccc NameError: name 'ccc' is not defined But this code: OldNameError = NameError class NameError(OldNameError): pass try: raise NameError("oo") except NameError: print "hi" Gives the

问题 Currently I have a error logging class like so: public class Log { public enum LogTypes { Info = 1, Error = 2, Warning = 3 } public string Message { get; set; } public LogTypes LogType { get; set; } public Log(string Message, LogTypes LogType) { this.Message = Message; this.LogType = LogType; } I have this initialiser for a new list: List<Log> LogList = new List<Log>(); How can I use LogList.Add(Message, LogType) instead of LogList.Add(new Log(Message, LogType)); ? I know it is a minor change