overriding

问题 I have an abstract page class looking like this: abstract class Page { public static function display() { self::displayHeader(); self::displayContent(); self::displayFooter(); } public static function displayContent() { print "<p>some content</p>"; } public static function displayHeader() { include_once(kContent . "HeaderContent.class.php"); HeaderContent::display(); } public static function displayFooter() { include_once(kContent . "FooterContent.class.php"); FooterContent::display(); } }; I

问题 I encountered some strange behavior in Firefox. I have a simple input[type=number] field and when I try to type a decimal value in it (e.g. 4.5), the browser puts an ugly red border around my input. <input type="number" /> How can I fix this and override this stupid behavior of Firefox? See jsFiddle 回答1: If you set a step="0.01" , then the border disappears. The number type has a step value controlling which numbers are valid (along with max and min), which defaults to 1. This value is also

问题 I'm trying to display information from a Cursor in a ListView , each row contains a ImageView and a TextView . I have a CustomCursorAdapter extending CursorAdapter , in bindView I evaluate the data from the cursor and based on that set the views image and text. When I run the app the ListView displayes the correct amount of rows, but they are empty. I know I have missed something when overriding bindView, but I'm not sure what. Any help would be greatly appreciated. private class

问题 I'm trying to display information from a Cursor in a ListView , each row contains a ImageView and a TextView . I have a CustomCursorAdapter extending CursorAdapter , in bindView I evaluate the data from the cursor and based on that set the views image and text. When I run the app the ListView displayes the correct amount of rows, but they are empty. I know I have missed something when overriding bindView, but I'm not sure what. Any help would be greatly appreciated. private class

问题 I'm new to Java, and I've read over some tutorials on overriding methods, but an example I'm looking at isn't working the way I expect. For example, I have the code: public class A{ public void show(){ System.out.println("A"); } public void run(){ show(); } public static void main( String[] arg ) { new A().run(); } } public class B extends A{ @Override public void show(){ System.out.println("B"); } } When I instantiate and call B.run(), I would expect to see "B" outputted. However, I see "A"

问题 I'm currently subclassing a UINavigationController for a framework that serves a view controller flow (in a way, like UIImagePickerController do) Here's an example of my implementation, reduced to be as simple as possible, that can be run in a playground. import UIKit public class MyNavigationController: UINavigationController { public var anyVar: Int? public init(anyVar: Int) { let viewController = UIViewController() super.init(rootViewController: viewController) self.anyVar = anyVar }

问题 I'd like to override the behavior of an std function, say std::time. Is it possible to call std::time and have it routed through my custom function? 回答1: The std namespace is off limits, generally speaking. Adding new functions, overloads, classes or anything else to the std namespace is **undefined behavior*. The only exception is template specializations . You may provide specializations of functions in the std namespace. A function where this is often done is std::swap . 回答2: This sounds

问题 On Class A I have this: protected function createTempTable() { $qry = ' CREATE TABLE `'.$this->temp_table.'` ( `style` VARCHAR( 255 ) NOT NULL , `description` VARCHAR( 255 ) NOT NULL , `metal` VARCHAR( 255 ) NOT NULL , `available` VARCHAR( 255 ) NOT NULL , `center_stone` VARCHAR( 255 ) NOT NULL , `total_weight` VARCHAR( 255 ) NOT NULL , `price` DECIMAL( 10, 2 ) NOT NULL , PRIMARY KEY ( `style` ) ) ENGINE = MYISAM ; '; $pdo = PDOManager::getConnection(); $sth = $pdo->query($qry); } Class B

问题 I trying to write some generic code, but can't get rid of Type of 'PROPERTY' is not a subtype of the overridden property error. Simplified version of my code: abstract class BaseP<V> { var view: V? = null } abstract class BaseF { fun smth() { pp.view = this } abstract val pp: BaseP<BaseF> } abstract class SubF: BaseF() { abstract override val pp: BaseP<SubF> // Error:(20, 30) Type of 'pp' is not a subtype of the overridden property 'public abstract val pp: BaseP<BaseF> defined in BaseF' } I

问题 I am learning c++ and am learning about the virtual keyword. I have scoured the internet trying to understand it to no avail. I went into my editor and did the following experiment, expecting it to print out the base message twice (because I was under the impression that the virtual keyword is needed to override functions). However, it printed out two different messages. Can someone explain to me why we need the virtual keyword if we can simply override functions and still seemingly get