Tutorial by Examples: di

In Objective-C, method swizzling is the process of changing the implementation of an existing selector. This is possible due to the way Selectors are mapped on a dispatch table, or a table of pointers to functions or methods. Pure Swift methods are not dynamically dispatched by the Objective-C run...

git diff [HEAD|--staged...] --word-diff Rather than displaying lines changed, this will display differences within lines. For example, rather than: -Hello world +Hello world! Where the whole line is marked as changed, word-diff alters the output to: Hello [-world-]{+world!+} You can omit...

To ignore a file foo.txt in any directory you should just write its name: foo.txt # matches all files 'foo.txt' in any directory If you want to ignore the file only in part of the tree, you can specify the subdirectories of a specific directory with ** pattern: bar/**/foo.txt # matches all file...

Custom views can also take custom attributes which can be used in Android layout resource files. To add attributes to your custom view you need to do the following: Define the name and type of your attributes: this is done inside res/values/attrs.xml (create it if necessary). The following file...

One way to create a macro is to record it. Start recording a macro and save it to a register (in this example, we'll use a, but it can be any register you could normally yank text to): qa Then run the commands you want to record in the macro (here, we'll surround the contents of a line with &lt...

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

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...

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 ...

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...

You can access SharedPreferences in several ways: Get the default SharedPreferences file: import android.preference.PreferenceManager; SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this); Get a specific SharedPreferences file: public static final String PREF_FILE_NAM...

The display CSS property is fundamental for controlling the layout and flow of an HTML document. Most elements have a default display value of either block or inline (though some elements have other default values). Inline An inline element occupies only as much width as necessary. It stacks horiz...

To add a header to a recyclerview with a gridlayout, first the adapter needs to be told that the header view is the first position - rather than the standard cell used for the content. Next, the layout manager must be told that the first position should have a span equal to the *span count of the e...

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...

There are few approaches available there: You can subscribe for keyboard appearance events notifications and change offset manually: //Swift 2.0+ override func viewDidLoad() { super.viewDidLoad() NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(YourVCClas...

To avoid verbose null checking, the ?. operator has been introduced in the language. The old verbose syntax: If myObject IsNot Nothing AndAlso myObject.Value >= 10 Then Can be now replaced by the concise: If myObject?.Value >= 10 Then The ? operator is particularly powerful when you...

Swift let alert = UIAlertController(title: "Hello", message: "Welcome to the world of iOS", preferredStyle: UIAlertControllerStyle.alert) let defaultAction = UIAlertAction(title: "OK", style: UIAlertActionS...

Custom Font Support Applications that want to use custom fonts can now include those fonts in their application bundle and register those fonts with the system by including the UIAppFonts key in their Info.plist file. The value of this key is an array of strings identifying the font files in the ...

<p contenteditable>This is an editable paragraph.</p> Upon clicking on the paragraph, the content of it can be edited similar to an input text field. When the contenteditable attribute is not set on an element, the element will inherit it from its parent. So all child text of a conte...

Look at the contents of /etc/redhat-release cat /etc/redhat-release Here is the output from a Fedora 24 machine: Fedora release 24 (Twenty Four) As mentioned in the debian-based response, you can also use the lsb_release -a command, which outputs this from a Fedora 24 machine: LSB Version: ...

Use existing .NET classes instantly with PowerShell by using [class]::Method(args): PS C:\> [guid]::NewGuid() Guid ---- 8874a185-64be-43ed-a64c-d2fe4b6e31bc Similarly, in PowerShell 5+ you may use the New-Guid cmdlet: PS C:\> New-Guid Guid ---- 8874a185-64be-43ed-a64c-d2fe4b6e31...