builder

问题 I was wondering what would be the best way to implement a .When condition in a fluent interface using method chaining in a Builder object? For instance how would I implement the .WithSkill() and .When() methods in the following example: var level = 5; var ninja = NinjaBuilder .CreateNinja() .Named("Ninja Boy") .AtLevel(level) .WithShurikens(10) .WithSkill(Skill.HideInShadows) .When(level > 3) .Build() Update - A sample solution can be found here. 回答1: What I'd do is have NinjaBuilder keep the

问题 In Kotlin, I want to add extension methods to a class, for example to class Entity . But I only want to see these extensions when Entity is within a transaction, otherwise hidden. For example, if I define these classes and extensions: interface Entity {} fun Entity.save() {} fun Entity.delete() {} class Transaction { fun start() {} fun commit() {} fun rollback() {} } I now can accidentally call save() and delete() at any time, but I only want them available after the start() of a transaction

问题 For the past few days, I haven't been able to solve an issue with my dialog box. I am running a thread to show the dialog box for 5000ms and removing it. and I am trying to show a toast("SUCCESS"). The problem is I am getting the dialog box for the second time also. I am new to android development and I need to solve this with Async Task so that I can delay the second thread and show a alert dialog.builder with a positive button instead of toast. I goggled a lot but I confused to to implement

问题 I have the following code: pub struct Canvas<\'a> { width: isize, height: isize, color: Color, surface: Surface, texture: Texture, renderer: &\'a Renderer, } impl<\'a> Canvas<\'a> { pub fn new(width: isize, height: isize, renderer: &\'a Renderer) -> Canvas<\'a> { let color = Color::RGB(0, 30, 0); let mut surface = core::create_surface(width, height); let texture = Canvas::gen_texture(&mut surface, width, height, color, renderer); Canvas { width: width, height: height, color: color, surface:

问题 My Activity is trying to create an AlertDialog which requires a Context as a parameter. This works as expected if I use: AlertDialog.Builder builder = new AlertDialog.Builder(this); However, I am leery of using \"this\" as a context due to the potential for memory leaks when Activity is destroyed and recreated even during something simple like a screen rotation. From a related post on the Android developer\'s blog: There are two easy ways to avoid context-related memory leaks. The most

问题 What are some common , real world examples of using the Builder Pattern? What does it buy you? Why not just use a Factory Pattern? 回答1: The key difference between a builder and factory IMHO, is that a builder is useful when you need to do lots of things to build an object. For example imagine a DOM. You have to create plenty of nodes and attributes to get your final object. A factory is used when the factory can easily create the entire object within one method call. One example of using a