callback

问题 My question has to do with modifying this example from the Bokeh Gallery. I have a matrix m or raw data, in which every row corresponds to a pair of x,y coordinates in a transformed space (see #MockData part of code). The x,y coordinates are plotted on the left plot. I am trying to change the example so that, when I select some points in the left figure, the right figure will display line plots of the corresponding rows. I've narrowed the problem down to the point, where the right figure will

问题 The following class contains a method that should calculate the integral using the callback technique. package integrals; import java.lang.*; public class Integrals { public static double f1(double x) { return x*5+Math.sin(x); } public static double f2(double x) { return Math.pow(x*f1(-x),x); } public static double TrapezoidalIntegration(double a,double b,int n,double (*f)(double)) { double rValue=0; double dx; dx=(b-a)/n; for(double i=f(a);i<f(b);i+=dx) rValue+=((f(i)+f(i+dx))*dx)/2.0;

问题 ES6 Promises are great. So far it’s been pretty easy to adjust my thinking from the callback idiom. I’ve found it naturally encourages more modular code, and of course error handling is much clearer. But a few times I’ve encountered flow situations that don’t seem(?) like they can be readily translated from nodebacks to promises (and perhaps that’s just that, but maybe I’m just blind to the answers). Since promises are agnostic about the next operation (or if there even is one), it seems

问题 ES6 Promises are great. So far it’s been pretty easy to adjust my thinking from the callback idiom. I’ve found it naturally encourages more modular code, and of course error handling is much clearer. But a few times I’ve encountered flow situations that don’t seem(?) like they can be readily translated from nodebacks to promises (and perhaps that’s just that, but maybe I’m just blind to the answers). Since promises are agnostic about the next operation (or if there even is one), it seems

问题 Can I have two different clients listening to the same WCF callback and have them both receive the same data without having to do the processing twice? 回答1: Not really - at least not directly. What you're describing sounds a lot like the publish/subscribe pattern. A WCF service basically services one client and one client only, at any given time. There are ways to do this in WCF 3.5 and better ones in WCF 4.0 - with or without Windows Azure's .NET Services. There are also other tools and

问题 Can I have two different clients listening to the same WCF callback and have them both receive the same data without having to do the processing twice? 回答1: Not really - at least not directly. What you're describing sounds a lot like the publish/subscribe pattern. A WCF service basically services one client and one client only, at any given time. There are ways to do this in WCF 3.5 and better ones in WCF 4.0 - with or without Windows Azure's .NET Services. There are also other tools and

问题 Just by seeing what I've wrote now, I can see that one is much smaller, so in terms of code golf Option 2 is the better bet, but as far as which is cleaner, I prefer Option 1 . I would really love the community's input on this. Option 1 something_async({ success: function(data) { console.log(data); }, error: function(error) { console.log(error); } }); Option 2 something_async(function(error,data){ if(error){ console.log(error); }else{ console.log(data); } }); 回答1: Many people will find option

问题 I have the following method in one of my C++ classes (using QtWebEngine): QString get() { QString result; view->page()->runJavaScript("test();", [this](const QVariant &v) { result = v.toString(); }); return result; } It is to execute test() JS function and return the result of this invocation. Unfortunately, the callback is asynchronous and the program crashes. How can I make it work? 回答1: The callback is asynchronous because the JavaScript execution occurs not only in another thread but in

问题 I want to filter an array, using the array_filter function. It hints at using call_user_func under water, but does not mention anything about how to use within the context of a class/object. Some pseudocode to explain my goal: class RelatedSearchBlock { //... private function get_filtered_docs() { return array_filter($this->get_docs(), 'filter_item'); } private filter_item() { return ($doc->somevalue == 123) } } Would I need to change 'filter_item' into array($this, 'filter_item') ? Is what I

问题 I want to filter an array, using the array_filter function. It hints at using call_user_func under water, but does not mention anything about how to use within the context of a class/object. Some pseudocode to explain my goal: class RelatedSearchBlock { //... private function get_filtered_docs() { return array_filter($this->get_docs(), 'filter_item'); } private filter_item() { return ($doc->somevalue == 123) } } Would I need to change 'filter_item' into array($this, 'filter_item') ? Is what I