Tutorial by Examples: f

ForEach() is defined on the List<T> class, but not on IQueryable<T> or IEnumerable<T>. You have two choices in those cases: ToList first The enumeration (or query) will be evaluated, copying the results into a new list or calling the database. The method is then called on each it...

Because of the reasons explained in Remarks section you can't simply do this (unless you want to count occurrences of a specific code-unit): int count = text.Count(x => x == ch); You need a more complex function: public static int CountOccurrencesOf(this string text, string character) { ...

We cannot break a string into arbitrary points (because a System.Char may not be valid alone because it's a combining character or part of a surrogate) then code must take that into account (note that with length I mean the number of graphemes not the number of code-units): public static IEnumerabl...

.NET strings contain System.Char (UTF-16 code-units). If you want to save (or manage) text with another encoding you have to work with an array of System.Byte. Conversions are performed by classes derived from System.Text.Encoder and System.Text.Decoder which, together, can convert to/from another ...

Sometimes a element needs to be created outside of the usual object structure in the fxml. This is where Define Blocks come into play: Contents inside a <fx:define> element are not added to the object created for the parent element. Every child element of the <fx:define> needs a fx:id...

If there are no specific needs, choose x86_64 system images with Google APIs to create the emulator. It works way faster than armeabi-v7a on intel x86 x64 based computers. There are some SDK libraries compiled and designed with ARM architecture. If you try to install them on Intel based emulators...

PropertyValueFactory can be used as cellValueFactory in a TableColumn. It uses reflection to access methods that match a certain pattern to retrieve the data from a TableView item: Example TableColumn<Person, String> nameColumn = ... PropertyValueFactory<Person, String> valueFactory =...

The following example encrypts data by using a hybrid cryptosystem consisting of AES GCM and OAEP, using their default parameter sizes and an AES key size of 128 bits. OAEP is less vulnerable to padding oracle attacks than PKCS#1 v1.5 padding. GCM is also protected against padding oracle attacks. ...

Long-running operations must not be run on the JavaFX application thread, since this prevents JavaFX from updating the UI, resulting in a frozen UI. Furthermore any change to a Node that is part of a "live" scene graph must happen on the JavaFX application thread. Platform.runLater can be...

The below examples use the new form API introduced in RC3. pw-change.template.html <form class="container" [formGroup]="pwChangeForm"> <label for="current">Current Password</label> <input id="current" formControlName="curr...

Characteristics of properties : Properties that can be retrieved from an object could have the following characteristics, Enumerable Non - Enumerable own While creating the properties using Object.defineProperty(ies), we could set its characteristics except "own". Properties which...

The .vimrc file (pronounced Vim-wreck) is a Vim configuration file. It holds commands that will be executed by Vim every time it starts. By default the file is empty or non-existent; you can use it to customize your Vim environment. To find out where Vim expects the vimrc file to be stored, open V...

In order to work with bindings in WPF, you need to define a DataContext. The DataContext tells bindings where to get their data from by default. <Window x:Class="StackOverflowDataBindingExample.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation&q...

INotifyPropertyChanged is an interface used by binding sources (i.e. the DataContext) to let the user interface or other components know that a property has been changed. WPF automatically updates the UI for you when it sees the PropertyChanged event raised. It is desirable to have this interface im...

You can bind to a property on a named element, but the named element must be in scope. <StackPanel> <CheckBox x:Name="MyCheckBox" IsChecked="True" /> <TextBlock Text="{Binding IsChecked, ElementName=MyCheckBox}" /> </StackPanel>

You can bind to a property of an ancestor in the visual tree by using a RelativeSource binding. The nearest control higher in the visual tree which has the same type or is derived from the type you specify will be used as the binding's source: <Grid Background="Blue"> <Grid ...

PS > Get-Member -InputObject $anObjectInstance This will return all members of the type instance. Here is a part of a sample output for String instance TypeName: System.String Name MemberType Definition ---- ---------- ---------- Clone ...

The Django template system has built-in tags and filters, which are functions inside template to render content in a specific way. Multiple filters can be specified with pipes and filters can have arguments, just as in variable syntax. {{ "MAINROAD 3222"|lower }} # mainroad 3222 {{ 10...

F# Interactive, is a REPL environment that lets you execute F# code, one line at a time. If you have installed Visual Studio with F#, you can run F# Interactive in console by typing "C:\Program Files (x86)\Microsoft SDKs\F#\4.0\Framework\v4.0\Fsi.exe". On Linux or OS X, the command is fsh...

The official style guide is located on the homepage and generally goes for: readability (instead of compactness) ease of modification clean diffs This means that, for example, this: homeDirectory : String homeDirectory = "/root/files" evaluate : Boolean -> Bool evalua...