Monthly Archives: March 2015

Let the user zoom on a picture in C#

The example Provide autosave in C# explains how to make a program that lets the user draw lines in different colors and styles. That program lets the user undo and redo, save and load drawings, and autosaves so it can … Continue reading

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Provide autosave in C#

This example extends the scribble example (most recently described in the post Provide undo and redo in C#) so it provides an auto-save feature. The following code creates the name of the program’s auto-save file. // The auto-save file name. … Continue reading

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Provide undo and redo in C#

This example adds undo and redo features to the example Save and restore pictures drawn by the user in C#. It’s not terribly hard, but it is long so I’ll break it into sections to make it easier to understand. … Continue reading

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Save and restore pictures drawn by the user in C#

The example Let the user scribble with different line styles in C# explains how to let the user draw curves with different colors, line thicknesses, and dash patterns. This example adds the ability to save and load pictures drawn by … Continue reading

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Let the user scribble with different line styles in C#

The example Let the user scribble on a PictureBox in C# explains how to let the user draw polylines, but the program only draws thin black curves. This example adds color, line thickness, and line styles such as dashed or … Continue reading

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Let the user scribble on a PictureBox in C#

The Graphics class provides a DrawLines method that draws a series of connected lines, which is sometimes called a polyline. This program lets the user create a series of polylines. The program stores the points that make up a polyline … Continue reading

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Use steganography to hide messages in an image in C#

Steganography is the science of hiding information within other information. For example, a watermark “hides” an image on a piece of paper. If you look at most paper currency at a low angle or if you hold it up to … Continue reading

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Graph several pi approximations in C#

This example graphs pi approximations by combining the techniques described in the following two posts: Approximate pi using several different methods in C# Graph pi approximations in C# For each series, the program uses the series to generate approximations for … Continue reading

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Approximate pi using several different methods in C#

The post In honor of Pi Day (3.14), approximate pi in C# uses the following sequence to approximate pi. That sequence is elegant but unfortunately it converges very slowly so you need to take a lot of terms to get … Continue reading

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Graph pi approximations in C#

My post In honor of Pi Day (3.14), approximate pi in C# uses the following series to approximate the value π. As you add terms to the series, the approximation alternates between values that are above and below the true … Continue reading

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