overriding

来源： https://stackoverflow.com/questions/9498769/override-annotation-and-jdk-1-5

来源： https://stackoverflow.com/questions/9498769/override-annotation-and-jdk-1-5

来源： https://stackoverflow.com/questions/45047559/java-parent-class-is-calling-a-method-from-a-child-class

问题 I'm fairly new to Java and would like to know how to accomplish the following task, and also, whether it is considered bad style, even if it is possible. Thank you. Fish f; // Fish is a superclass, Tuna t = new Tuna(); // to which Tuna is a subclass. f=t; // the Fish object "f" now refers to the Tuna object "t". // Both Fish and Tuna have an identical method (signature wise) called swim() , f.swim(); // and so Tuna's overridden swim() method is invoked here. But can I now get Fish's swim()

问题 I am getting below warning . part of my code is : class Base { public: virtual void process(int x) {;}; virtual void process(int a,float b) {;}; protected: int pd; float pb; }; class derived: public Base{ public: void process(int a,float b); } void derived::process(int a,float b){ pd=a; pb=b; .... } I am getting below warning : Warning: overloaded virtual function "Base::process" is only partially overridden in class "derived" any way i have made process as virtual function so I am expecting

问题 I am getting below warning . part of my code is : class Base { public: virtual void process(int x) {;}; virtual void process(int a,float b) {;}; protected: int pd; float pb; }; class derived: public Base{ public: void process(int a,float b); } void derived::process(int a,float b){ pd=a; pb=b; .... } I am getting below warning : Warning: overloaded virtual function "Base::process" is only partially overridden in class "derived" any way i have made process as virtual function so I am expecting

问题 Does anybody know is it possible to open some personal picture when emulator camera starts? I have an application which is based on image analysis and I would like when I click a button for camera that camera opens not that default Android emulator moving image. I want it to open some image which I set as a default image. So when I choose to take a picture it will show only that image and when I take a take a picture, that image will be saved to gallery, not Android default image. 回答1:

问题 in my MainActivity, which extends from AppCompatActivity, I want to override the onBackPressed method like so: @Override public void onBackPressed() { Log.d("MainActivity","onBackPressed"); Toast.makeText(getApplicationContext(),"onBackPressed",Toast.LENGTH_SHORT).show(); } but onBackPressed does not get called. How ever if I do not override onBackPressed, the application closes, when I press the backbutton and if I do override it it doesn't. The rest of my activity looks like this: public

问题 This question already has answers here : Why does an overridden function in the derived class hide other overloads of the base class? (4 answers) Closed 6 years ago . In the following code, "d.Foo()" throws a compiler error claiming that function Foo() does not take 0 arguments. Yet a 0-argument function with that name exists in the base class. The line "d.Base::Foo()" is acceptable. I have a vague memory of learning that the use of a function name in a derived class hides all functions of

问题 This question already has answers here : Why does an overridden function in the derived class hide other overloads of the base class? (4 answers) Closed 6 years ago . In the following code, "d.Foo()" throws a compiler error claiming that function Foo() does not take 0 arguments. Yet a 0-argument function with that name exists in the base class. The line "d.Base::Foo()" is acceptable. I have a vague memory of learning that the use of a function name in a derived class hides all functions of