Tutorial by Examples: r

Hello World

This example creates a Polymer element named x-foo, whose template binds to a string property, named "message". The element's HTML is imported into the main document, which allows usage of <x-foo> tags in <body>. x-foo.html <dom-module id="x-foo"> <templ...

Create a UIWebView instance

Swift let webview = UIWebView(frame: CGRect(x: 0, y: 0, width: 320, height: 480)) Objective-C UIWebView *webview = [[UIWebView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)]; //Alternative way of defining frame for UIWebView UIWebView *webview = [[UIWebView alloc] init]; CGRect webviewFr...

Making a URL request

Load content in webview from the url Swift webview.loadRequest(NSURLRequest(URL: NSURL(string: "http://www.google.com")!)) Objective-C [webview loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.google.com"]]];

Beautify or Pretty-Print XML

The PrettyPrinter utility will 'pretty print' XML documents. The following code snippet pretty prints unformatted xml: import scala.xml.{PrettyPrinter, XML} val xml = XML.loadString("<a>Alana<b><c>Beth</c><d>Catie</d></b></a>") val formatt...

throw, catch

Unlike many other programming languages, the throw and catch keywords are not related to exception handling in Ruby. In Ruby, throw and catch act a bit like labels in other languages. They are used to change the control flow, but are not related to a concept of "error" like Exceptions are...

Split strings using regular expressions

The library CL-PPCRE provides the function split which allows us to split strings in substrings that match a regular expression, discarding the parts of the string that do not. (cl-ppcre:split "\\." "127.0.0.1") ;; => ("127" "0" "0" "1&quot...

Using std::async instead of std::thread

std::async is also able to make threads. Compared to std::thread it is considered less powerful but easier to use when you just want to run a function asynchronously. Asynchronously calling a function #include <future> #include <iostream> unsigned int square(unsigned int i){ r...

Method parameters

If you want to pass in values to a method when it is called, you use parameters: - (int)addInt:(int)intOne toInt:(int)intTwo { return intOne + intTwo; } The colon (:) separates the parameter from the method name. The parameter type goes in the parentheses (int). The parameter name goes aft...

Create a basic method

This is how to create a basic method that logs 'Hello World" to the console: - (void)hello { NSLog(@"Hello World"); } The - at the beginning denotes this method as an instance method. The (void) denotes the return type. This method doesn't return anything, so you enter void. ...

Return values

When you want to return a value from a method, you put the type you want to return in the first set of parentheses. - (NSString)returnHello { return @"Hello World"; } The value you want to return goes after the return keyword;

Asserting

@implemenetation Triangle ... -(void)setAngles:(NSArray *)_angles { self.angles = _angles; NSAssert((self.angles.count == 3), @"Triangles must have 3 angles. Array '%@' has %i", self.angles, (int)self.angles.count); CGFloat angleA = [self.angles[0] floatVal...

Introduction to Broadcast receiver

A Broadcast receiver is an Android component which allows you to register for system or application events. A receiver can be registered via the AndroidManifest.xml file or dynamically via the Context.registerReceiver() method. public class MyReceiver extends BroadcastReceiver { @Override ...

.where

The where method is available on any ActiveRecord model and allows querying the database for a set of records matching the given criteria. The where method accepts a hash where the keys correspond to the column names on the table that the model represents. As a simple example, we will use the foll...

.where with an array

The where method on any ActiveRecord model can be used to generate SQL of the form WHERE column_name IN (a, b, c, ...). This is achieved by passing an array as argument. As a simple example, we will use the following model: class Person < ActiveRecord::Base #attribute :first_name, :string ...

Adding a package source feed (MyGet, Klondike, ect)

nuget sources add -name feedname -source http://sourcefeedurl

String formatting in strings.xml

Defining Strings in the strings.xml file also allows for string formatting. The only caveat is that the String will need to be dealt with in code like below, versus simply attaching it to a layout. <string name="welcome_trainer">Hello Pokémon Trainer, %1$s! You have caught %2$d Poké...

Calling virtual methods in constructor

Unlike C++ in C# you can call a virtual method from class constructor (OK, you can also in C++ but behavior at first is surprising). For example: abstract class Base { protected Base() { _obj = CreateAnother(); } protected virtual AnotherBase CreateAnother() { ...

Creating a CALayer

You can create a CALayer and set its frame like this: Swift: let layer = CALayer() layer.frame = CGRect(x: 0, y: 0, width: 60, height: 80) Objective-C: CALayer *layer = [[CALayer alloc] init]; layer.frame = CGRectMake(0, 0, 60, 80); You can then add it as a sublayer to an existing CALayer...
iOS • CALayer

Adding an action to an UIButton via Code (programmatically)

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...

Creating a simple button

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...

Page 136 of 1016

logo rip
SUPPORT & PARTNERS
STAY CONNECTED

Get monthly updates about new articles, cheatsheets, and tricks.