Tutorial by Examples: u

Detailed instructions on getting testing set up or installed.

Sometimes, if an action should be bind to a collection view's cell selection, you have to implement the UICollectionViewDelegate protocol. Let's say the collection view is inside a UIViewController MyViewController. Objective-C In your MyViewController.h declares that it implements the UICollecti...

Provided that barButtonItem has a non-null image property (e.g. set in the Interface Builder). Objective-C barButtonItem.image = [barButtonItem.image imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];

-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> *)change context:(void *)context Context is important if you ship your class for others to use.Context lets your class observer verify that its you observer which is being called. The ...

If you are using library that contains (for example) AwesomeViewController with a wrong status bar color you can try this: let awesomeViewController = AwesomeViewController() awesomeViewController.navigationBar.barStyle = .blackTranslucent // or other style

Classes can implement more than one interface, as opposed to inheriting from more than one class (Multiple Inheritance) which isn't possible for Delphi classes. To achieve this, the name of all interfaces must be added comma-separated behind the base class. Of course, the implementing class must al...

When using the DllImport attribute you have to know the correct dll and method name at compile time. If you want to be more flexible and decide at runtime which dll and methods to load, you can use the Windows API methods LoadLibrary(), GetProcAddress() and FreeLibrary(). This can be helpful if the ...

First obtain the Microsoft.CodeAnalysis.CSharp.Workspaces nuget before continuing. var workspace = Microsoft.CodeAnalysis.MSBuild.MSBuildWorkspace.Create(); var project = await workspace.OpenProjectAsync(projectFilePath); var compilation = await project.GetCompilationAsync(); foreach (var diag...

The outline-style property is used to set the style of the outline of an element. p { border: 1px solid black; outline-color:blue; line-height:30px; } .p1{ outline-style: dotted; } .p2{ outline-style: dashed; } .p3{ outline-style: solid; } .p4{ outline-style: double; }...

Name-based virtual hosting on Apache is described on the Apache website as such: With name-based virtual hosting, the server relies on the client to report the hostname as part of the HTTP headers. Using this technique, many different hosts can share the same IP address. Therefore, more than...

This command will save the open file with sudo rights :w !sudo tee % >/dev/null You can also map w!! to write out a file as root :cnoremap w!! w !sudo tee % >/dev/null

Add this to your $MYVIMRC: " Source vim configuration file whenever it is saved if has ('autocmd') " Remain compatible with earlier versions augroup Reload_Vimrc " Group name. Always use a unique name! autocmd! " Clear any preexisting autoc...

An SSH key has two pieces, the public key and the private key. The private key: Is usually in a file named id_rsa, but it can be given any name. CANNOT BE REGENERATED IF LOST!!!! Do not lose this file! If you lose it, you will not be able to get back into your instance. (StackOverflow is li...

In the root of your ionic app, there is a gulpfile.js file. Open it in an editor and paste the following gulp task: gulp.task('lint', function() { return gulp.src(['./www/js/**/*.js']) .pipe(jshint('.jshintrc')) .pipe(jshint.reporter('jshint-stylish')) .pipe(jshint...

You can restart ubuntu from command line. Below is example of restarting ubuntu immediately. sudo reboot You need to have sudo privilege in order to use this command. Another commands with same results are sudo shutdown -r now and sudo init 6.

In some places in Common Lisp, a series of forms are evaluated in order. For instance, in the body of a defun or lambda, or the body of a dotimes. In those cases, writing multiple forms in order works as expected. In a few places, however, such as the then and else parts of an if expressions, onl...

When writing macros that expand into forms that might involve grouping, it is worthwhile spending some time considering what grouping construction to expand into. For definition style forms, for instance, a define-widget macro that will usually appear as a top-level form, and that several defuns, d...

You can use npm install -g to install a package "globally." This is typically done to install an executable that you can add to your path to run. For example: npm install -g gulp-cli If you update your path, you can call gulp directly. On many OSes, npm install -g will attempt to writ...

Node Version Manager (nvm) greatly simplifies the management of Node.js versions, their installation, and removes the need for sudo when dealing with packages (e.g. npm install ...). Fish Shell (fish) "is a smart and user-friendly command line shell for OS X, Linux, and the rest of the family&...

Square Root Use Math.sqrt() to find the square root of a number Math.sqrt(16) #=> 4 Cube Root To find the cube root of a number, use the Math.cbrt() function 6 Math.cbrt(27) #=> 3 Finding nth-roots To find the nth-root, use the Math.pow() function and pass in a fractional expo...