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Supported argument types

CommandLineParser library allows you to define arguments of your own (via deriving from Argument class), but there are several argument types already included and ready to use.


You can use SwitchArgument to define an argument with true/false logic. Switch argument has its default value - the initial value and value that argument holds when the user does not use the argument on the command line. Each time the user uses the argument, the value is flipped. Suppose "Finder" application that has "distinct" switch argument with default value false. This usage:

Finder.exe --distinct

flips the value of distinct argument to true. Note that the switch argument is not followed by value therefore this: Finder.exe --distinct false would result in something that the user probably didn't want - default value of "distinct" argument (false) would be flipped to true and the word false would be interpreted as an additional argument not related to "distinct" argument. To define a bool argument followed by value, use ValueArgument<bool> instead.


You can use ValueArgument to define an argument with value (of any type). User can then type the argument and its value on the command line. Suppose "Finder" application that has "subdirectories" argument with integer value. You would define it as ValueArgument<int> and then it could be used like this:

Finder.exe --subdirectories 3

ValueArgument class takes care of parsing the value and converting it to the right type. For built-in C# types (bool, int, double, string, char etc.) the static .NET function Parse is used. If you want to use some other type (your class or struct for example) as arguments value, you have to specify a conversion routine that converts string on the command line to your type.


EnumeratedValueArgument is similar to ValueArgument only its values must belong to a user defined set of possible values. Remark - if you want to map the set of values to your Enum type, you can use ValueArgument<TValue> where TValue is your Enum type.


BoundedValueArgument is similar to ValueArgument and EnumeratedValueArgument. You can use any comparable type as TValue (type implementing IComparable) and define minimum and maximum allowed value of the argument.


FileArgument can be used to define input and output files for the program. The value of the argument is of type FileInfo and via property FileArgument.FileMustExist you can declare whether the file must already exist (useful for input files) or not.


DirectoryArgument can be used to specify directory in the file system. The value of the argument is of type DirectoryInfo and via property DirectoryArgumet.DirectoryMustExist you can declare whether the file must already exist or not.

Last edited Apr 26, 2009 at 6:27 PM by Trupik, version 1


ryansmith Mar 8, 2011 at 6:56 PM 
I found the switch argument non-intuitive to use: the value was always false, even if I set true as the default value in SwitchArgument. I was probably using it wrong, but I just opted to use bool value argument, as that works as expected.