Tutorial by Examples: d

public class App : Application { internal static NavigationPage NavPage; public App () { // The root page of your application MainPage = new RootPage(); } } public class RootPage : MasterDetailPage { public RootPage() { var menuPage = ne...

You can use re.finditer to iterate over all matches in a string. This gives you (in comparison to re.findall extra information, such as information about the match location in the string (indexes): import re text = 'You can try to find an ant in this string' pattern = 'an?\w' # find 'an' either w...

The Windows API GetTickCount function returns the number of milliseconds since the system (computer) was started. The simplest example follows: var Start, Stop, ElapsedMilliseconds: cardinal; begin Start := GetTickCount; // do something that requires measurement Stop := GetTickCount; ...

Appearance : Trying to access an array by a key that does not exist in the array Possible Solution : Check the availability before accessing it. Use: isset() array_key_exists()

Appearance : Happens when your script tries to send a HTTP header to the client but there already was output before, which resulted in headers to be already sent to the client. Possible Causes : Print, echo: Output from print and echo statements will terminate the opportunity to send HTTP hea...

What is XAMPP? XAMPP is the most popular PHP development environment. XAMPP is a completely free, open-source and easy to install Apache distribution containing MariaDB, PHP, and Perl. Where should I download it from? Download appropriate stable XAMPP version from their download page. Choose the ...

Assume an application with a MainActivity which can call the Next Activity using a button click. public class MainActivity extends AppCompatActivity { private final String LOG_TAG = MainActivity.class.getSimpleName(); @Override protected void onCreate(Bundle savedInstanceState) { ...

The below code example will give you an adjusted version of that color where a higher percentage will be brighter and a lower percentage will be darker. Objective-C + (UIColor *)adjustedColorForColor:(UIColor *)c : (double)percent { if (percent < 0) percent = 0; CGFloat r, g, b...

Premise The most confusing thing surrounding pointer syntax in C and C++ is that there are actually two different meanings that apply when the pointer symbol, the asterisk (*), is used with a variable. Example Firstly, you use * to declare a pointer variable. int i = 5; /* 'p' is a pointer to a...

When performing tasks asynchronously there typically becomes a need to ensure a piece of code is run on the main thread. For example you may want to hit a REST API asynchronously, but put the result in a UILabel on the screen. Before updating the UILabel you must ensure that your code is run on th...

Avoid code repetition in constructors by setting a tuple of variables with a one liner: class Contact: UIView { private var message: UILabel private var phone: UITextView required init?(coder aDecoder: NSCoder) { (message, phone) = self.dynamicType.setUp() su...

@IBOutlet weak var title: UILabel! { didSet { label.textColor = UIColor.redColor() label.font = UIFont.systemFontOfSize(20) label.backgroundColor = UIColor.blueColor() } } It's also possible to both set a value and initialize it: private var loginButton = UIButton() { ...

Strings can be assigned directly to byte arrays and visa-versa. Remember that Strings are stored in a Multi-Byte Character Set (see Remarks below) so only every other index of the resulting array will be the portion of the character that falls within the ASCII range. Dim bytes() As Byte Dim exampl...

Add a key named Required background modes in property list (.plist) file .. as following picture.. And add following code in AppDelegate.h #import <AVFoundation/AVFoundation.h> #import <AudioToolbox/AudioToolbox.h> AppDelegate.m in application didFinishLaunchingWithOptions [[...

public class MyDataExporterToExcell { public static void Main() { GetAndExportExcelFacade facade = new GetAndExportExcelFacade(); facade.Execute(); } } public class GetAndExportExcelFacade { // All services below do something by themselves, determine l...

Suppose you have two lists: A and B, and you need to find the elements that exist in both lists. You can do it by just invoking the method List.retainAll(). Example: public static void main(String[] args) { List<Integer> numbersA = new ArrayList<>(); List<Integer> numb...

Intent: Define an interface for creating an object, but let sub classes decide which class to instantiate. Factory Method lets a class defer instantiation to sub classes. UML diagram: Product: It defines an interface of the objects the Factory method creates. ConcreteProduct: Implements Produc...

The Builder pattern allows you to create an instance of a class with many optional variables in an easy to read way. Consider the following code: public class Computer { public GraphicsCard graphicsCard; public Monitor[] monitors; public Processor processor; public Memory[] r...

Assume you have a application that administers rooms. Assume further that your application operates on a per client basis (tenant). You have several clients. So your database will contain one table for clients, and one for rooms. Now, every client has N rooms. This should mean that you have...

Another way to hide admin bar is to add if ( !current_user_can( 'manage_options' ) ) { add_filter( 'show_admin_bar', '__return_false' , 1000 ); } The users who don't have privileges to access Settings page, won't be able to see the admin bar.