The set of useful methods that can make developer life easer

Take a look at a list below and you may find a few methods that save your time.The sources  and documentation are here.

Array

GetMissingItems
Gets a list of the items in an array missing from a second array.

RemoveDups
Removes any duplicate items for a list of items.

StringArrayToString
Converts an array of strings into a string.

Collection

CollectionToHtmlTable
Converts a collection to an html string having a table.

Color

ColorToHtml
Converts a color into an html hexadecimal string.

GetColorTable
Get an html table listing color, html hexadecimal, and color name.

GetRandomColor
Gets a random color.

DataSet

ArrayToDataTable
Converts an array of strings to a DataTable.

DataTable2ExcelString
Coverts a DataTable into an Excel string.

DataTableToArray
Creates a string array from a DataTable.

DataTableToString
Converts a DataTable to a string with an html table.

FilterSortData
Filter and sort a dataset.

DateTime

CountWeekdays
Counts the number of weekdays between two dates.

CountWeekends
Counts the number of weekends between two dates.

IsDate
Checks whether an object is a date.

IsWeekDay
Returns true of day is weekday, otherwise false.

IsWeekEnd
Returns true of day is weekend, otherwise false.

TimeBreakdown
Returns a string that enumerates years, months, days, etc.

File

ArrayToFile
Saves a string array as a text file.

FileToArray
Converts the contents of a file to a string array.

GetDirectoryFileInfo
Gets information about the files in a directory and puts it in an array of strings.

GetDirectoryInfo
Gets information about a directory and puts it in an array of strings.

GetFileInfo
Gets information about a file and puts it in an array of strings.

ReadFromFile
Reads from a text file, puts the contents of the file in a string, and returns the string.

WriteToFile
Writes the passed in string to a file.

Forms

SetCheckboxesSelect
Adds a check to the checkboxes whose values are passed in.

SetComboSelectedIndex
Sets which item is selected in a DropDownList.

Math

Triangulate
Sums the numbers from 1 to n.

UnTriangulate
Undoes the Triangulate method.

Network

DNSLookup
Gets DNS information about a url and puts it in an array of strings.

GetHttpHeaders
Gets Http Headers and puts them in an array of strings.

GetImages
Gets the images from a webpage.

GetLinks
Gets the links from a webpage.

GetServerVariables
Gets the ServerVariables and puts them in a string.

ReadWebPage
Reads a web page and returns a string with the contents.

SendMail
Sends an e-mail message.

SendNetSend
Sends a net send message.

Numbers

GetDoubles
Gets an array of double values from the start value to the end value.

GetInts
Gets an array of int values from the start value to the end value.

GetRandomNumber
Gets a random number.

IsNumeric
Check whether an object is numeric.

Stats

GetAvg
Gets the average of an array of doubles or an array of ints.

GetCorrelation
Gets the Correlation between two arrays of numbers.

GetStandardDeviation
Gets the standard deviation of a list of numbers.

Strings

CountStrings
Count how many times a string appears.

GetASCII
Gets a string with ASCII characters.

ProperCase
Converts a string to proper case.

RemoveWhiteSpace
Remove extra white space in a string.