Tag Archives: classes

Make a simple event logger in C#

Posted on March 27, 2017 by Rod Stephens

Usually the debugger lets you examine how a program works quite effectively, but sometimes it’s useful to use an event logger to record events for later study. For example, when you’re working with mouse events, stopping execution at a break … Continue reading →

Posted in classes, debugging, files | Tagged C#, C# programming, classes, debugging, event logger, example, example program, files, log event, log file, Windows Forms programming | Leave a comment

Give a class default indexer properties in C#

Posted on March 20, 2017 by Rod Stephens

An indexer property is a property that other code can use inside square brackets to access some value provided by the class, much as you can use the index of an array. Unlike an array, a class’s indexer need not … Continue reading →

Posted in arrays, classes, syntax | Tagged arrays, C#, C# programming, classes, default property, example, example program, indexer property, syntax, Windows Forms programming | Leave a comment

Use a TextFieldParser to read fixed-width data in C#

Posted on February 11, 2017 by Rod Stephens

This example uses a TextFieldParser object to load fixed-width data from a file that contains names and addresses. Each field has a fixed width. Some records also have ZIP+4 format ZIP codes (for example, 08109-2120) and the program should discard … Continue reading →

Posted in classes, database, files, parsing | Tagged C#, C# programming, classes, data, data file, database, delimited fields, example, example program, files, fixed-width data, fixed-width fields, parse fields, parsing, TextFieldParser, Windows Forms programming | Leave a comment

Use a TextFieldParser to read delimited data in C#

Posted on February 10, 2017 by Rod Stephens

This example uses a TextFieldParser object to parse a data file that contains name and address data. The data contains fields delimited by commas and semi-colons. Some records also have ZIP+4 format ZIP codes (for example, 08109-2120) and the program … Continue reading →

Posted in classes, database, files, parsing | Tagged C#, C# programming, classes, data, data file, database, delimited fields, example, example program, files, parse fields, parsing, TextFieldParser, Windows Forms programming | 2 Comments

Draw a scrolling family tree in C#

Posted on January 17, 2017 by RodStephens

The example Draw a family tree in C# shows how to draw a family tree. Unfortunately if the tree is too big, you can’t make the form big enough to display it all. One solution would be to use smaller … Continue reading →

Posted in algorithms, classes, generic, graphics, OOP | Tagged algorithms, AutoScroll, C#, C# programming, classes, example, example program, family tree, generic, generic classes, graphics, MouseDown, MouseMove, nodes containing pictures, OOP, PictureNode, scroll bars, scrolling family tree, tree containing pictures, TreeNode, trees, Windows Forms programming | 1 Comment

Add “extension properties” to classes in C#

Posted on December 10, 2016 by Rod Stephens

Extension methods allow you to add new methods to existing classes even if you don’t have access to the classes’ source code. For example, the Randomize two-dimensional arrays in C# example shows how to add an extension method to two-dimensional … Continue reading →

Posted in algorithms, classes, extension methods | Tagged algorithms, C#, C# programming, classes, example, example program, extension methods, extension properties, extension property, Windows Forms programming | 1 Comment

Draw trees vertically or horizontally in C#

Posted on August 22, 2016 by Rod Stephens

The example Handle generic TreeNode mouse events in C# shows how to build a generic node class that can draw trees with nodes that contain just about anything. In that example, each each node is centered over its subtree. This … Continue reading →

Posted in algorithms, classes, drawing, graphics | Tagged add node, add tree node, algorithms, C#, C# programming, classes, delete node, delete tree node, drawing, example, example program, generic, generic classes, graphics, MouseDown, MouseMove, TreeNode, trees, Windows Forms programming | 3 Comments

Override a parent class method in C#

Posted on May 3, 2016 by Rod Stephens

One of the coolest features of object-oriented programming is virtual methods. If a parent class declares a method as virtual, a child class can provide a new implementation for the method. When the program calls the method for a child … Continue reading →

Posted in classes, OOP | Tagged C#, C# programming, child class, classes, example, example program, inheritance, object-oriented programming, OOP, override, parent class, virtual, Windows Forms programming | Leave a comment

Make an initializing constructor for a child class in C#

Posted on May 3, 2016 by Rod Stephens

An initializing constructor is a constructor that takes parameters to make it easy to initialize an object’s properties. This example shows how to reuse a class’s initializing constructor for a child class. The following Person class has an initializing constructor. … Continue reading →

Posted in classes, OOP | Tagged base class, C#, C# programming, child class, classes, constructors, example, example program, initialization, initialize, initializing constructors, OOP, parent class, subclass, Windows Forms programming | Leave a comment

Use the is operator in C#

Posted on April 8, 2016 by Rod Stephens

The is operator lets you determine whether you can convert an object to a particular type. For example, suppose the Student class inherits from Person, and that student and person are objects from the obvious classes. Then, for example, the … Continue reading →