Monthly Archives: August 2017

Make the user enter a float in C#

The posts Preview TextBox changes in C# and Preview TextBox changes in C#, Part 2 show how you can make a TextBox accept only integers. This example is similar except it makes a TextBox only accept floats. This change is … Continue reading

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Preview TextBox changes in C#, Part 2

Part 1 of this post explained how the example previews changes made by keyboard events. It then accepts or cancels the changes depending on whether the TextBox control’s new value is a valid integer (or the start of one as … Continue reading

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Preview TextBox changes in C#

One of the more annoying omissions from the Windows Forms controls is a way to preview changes to a TextBox before they occur. For example, suppose you want the user to enter a floating point value in a TextBox. The … Continue reading

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Use Array methods in C#

The example Sort and search arrays in C# shows how to use two useful Array methods: Sort and BinarySearch. This example demonstrates some other useful Array methods. For simplicity, this example uses arrays of characters to demonstrate the Array methods, … Continue reading

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Puzzle: Zero rows and columns in an array in C#

This puzzle is given as a coding example in the book Cracking the Coding Interview by Gayle Laakmann McDowell. The puzzle is: Write an algorithm such that if an element in an M x N matrix is 0, its entire … Continue reading

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Compare performance looping over DateTime and integer variables in C#

The example Find Friday the Thirteenths in C# doesn’t really worry about performance. It uses integers to loop over the dates within a range. For every year between the start and end dates, the code considers the 13th of each … Continue reading

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Find Friday the Thirteenths in C#

The following code shows how this example lists the Friday the Thirteenths between selected start and end dates. // List Friday the 13ths between the start and end dates. private void btnGo_Click(object sender, EventArgs e) { lstResults.Items.Clear(); // Get the … Continue reading

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Use == and != to compare structs in C#

This example shows how you can overload the == and != operators to make it easier to compare structs. By default, for reference types (classes), == returns true if two references refer to the same object (reference equality). It returns … Continue reading

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Book Review: Super Scratch Programming Adventure!: Learn to Program By Making Cool Games

Super Scratch Programming Adventure! Learn to Program By Making Cool Games $24.95, 160 pages, 2012 By the LEAD Project No Starch Press ISBN 13: 978-1593274092 A great, non-threatening introduction to programming This book’s subtitle is, “Learn to program by making … Continue reading

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Animate rainbow colors in C#

The example Map numeric values to and from colors in a color gradient in C# draws a color gradient that uses rainbow colors. This example animates that one. When you click on the color gradient, the following code starts or … Continue reading

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