Tutorial by Examples: on

To add a method to a button, first create an action method: Objective-C -(void)someButtonAction:(id)sender { // sender is the object that was tapped, in this case its the button. NSLog(@"Button is tapped"); } Swift func someButtonAction() { print("Button is tapped...

You can easily transform every component in a clickable button using the MouseArea component. The code below displays a 360x360 window with a button and a text in the center; pressing the button will change the text: import QtQuick 2.0 Rectangle { width: 360 height: 360 Rectang...

To find all the files of a certain extension within the current path you can use the following find syntax. It works by making use of bash's built-in glob construct to match all the names having the .extension. find /directory/to/search -maxdepth 1 -type f -name "*.extension" To find ...

Subclass UINavigationController and then override these methods: In Objective-C: - (UIStatusBarStyle)preferredStatusBarStyle { return UIStatusBarStyleLightContent; } In Swift: override func preferredStatusBarStyle() -> UIStatusBarStyle { return .lightContent } Alternativel...

Note that you cannot overload a function based on its return type. For example: // WRONG CODE std::string getValue() { return "hello"; } int getValue() { return 0; } int x = getValue(); This will cause a compilation error as the compiler will not be able to work out wh...

It is also possible to write a context manager using generator syntax thanks to the contextlib.contextmanager decorator: import contextlib @contextlib.contextmanager def context_manager(num): print('Enter') yield num + 1 print('Exit') with context_manager(2) as cm: # the ...

Intents can be used to broadcast messages to other components of your application (such as a running background service) or to the entire Android system. To send a broadcast within your application, use the LocalBroadcastManager class: Intent intent = new Intent("com.example.YOUR_ACTION"...

This code selects data out of a table and displays it in the query tool (usually SSMS) SELECT Column1, Column2, Column3 FROM MySourceTable; This code inserts that data into a table: INSERT INTO MyTargetTable (Column1, Column2, Column3) SELECT Column1, Column2, Column3 FROM MySourceTable;

This code selects data out of a table: SELECT Column1, Column2, Column3 FROM MySourceTable; This code creates a new table called MyNewTable and puts that data into it SELECT Column1, Column2, Column3 INTO MyNewTable FROM MySourceTable;

Since C# 6.0 exceptions can be filtered using the when operator. This is similar to using a simple if but does not unwind the stack if the condition inside the when is not met. Example try { // ... } catch (Exception e) when (e.InnerException != null) // Any condition can go in here. { ...

Within a catch block the throw keyword can be used on its own, without specifying an exception value, to rethrow the exception which was just caught. Rethrowing an exception allows the original exception to continue up the exception handling chain, preserving its call stack or associated data: try...

You can use the CONVERT function to cast a datetime datatype to a formatted string. SELECT GETDATE() AS [Result] -- 2016-07-21 07:56:10.927 You can also use some built-in codes to convert into a specific format. Here are the options built into SQL Server: DECLARE @convert_code INT = 100 -- See ...

A Sub is a procedure that performs a specific task but does not return a specific value. Sub ProcedureName ([argument_list]) [statements] End Sub If no access modifier is specified, a procedure is Public by default. A Function is a procedure that is given data and returns a value, ideally...

SRXMPPDemo Download the example and all the classes here - https://github.com/SahebRoy92/SRXMPPDemo A demo on XMPP in Objective C, with various simple and complex features implemented in it. All the features of XMPP is done by "in band" xmpp functions. Few features this project contains...

Using the Array::new constructor, your can initialize an array with a given size and a new array in each of its slots. The inner arrays can also be given a size and and initial value. For instance, to create a 3x4 array of zeros: array = Array.new(3) { Array.new(4) { 0 } } The array generated a...

Define your class that will represent your custom error. public class ErrorDto { public int Code { get; set; } public string Message { get; set; } // other fields public override string ToString() { return JsonConvert.SerializeObject(this); } } Then put nex...

The idea is to use HttpContext.Response.OnStarting callback, as this is the last event that is fired before the headers are sent. Add the following to your middleware Invoke method. public async Task Invoke(HttpContext context) { context.Response.OnStarting((state) => { if ...

The class we are going to test is: public class Service{ private Collaborator collaborator; public Service(Collaborator collaborator){ this.collaborator = collaborator; } public String performService(String input){ return collaborator.transformS...

Enumerable is the most popular module in Ruby. Its purpose is to provide you with iterable methods like map, select, reduce, etc. Classes that use Enumerable include Array, Hash, Range. To use it, you have to include Enumerable and implement each. class NaturalNumbers include Enumerable de...

The core concepts of RxJava are its Observables and Subscribers. An Observable emits objects, while a Subscriber consumes them. Observable Observable is a class that implements the reactive design pattern. These Observables provide methods that allow consumers to subscribe to event changes. The ev...