C#命令行参数解析类以及使用实例
编写命令行程序时如何进行命令行参数解析至关重要，下面将引用codeproject里面的一个命令行参数解析类并阐述如何使用来说明C#命令行参数解析的过程。
先看参数解析类，分为CommandLine类以及CommandArgs类，前者负责解析，后者负责结果封装，解析的结果分为三类：即 a=b 对应的key/value类型，-a b 对应的option与option value(可省略，值即转为true)，以及单独的aaa所对应的param类型。
//---------------------------------------------------------------------
///
/// Contains the parsed command line arguments. This consists of two
/// lists, one of argument pairs, and one of stand-alone arguments.
///
public class CommandArgs
{
//---------------------------------------------------------------------
///
/// Returns the dictionary of argument/value pairs.
///
public Dictionary<string, string> ArgPairs
{
get { return mArgPairs; }
}
Dictionary<string, string> mArgPairs = new Dictionary<string, string>();
//---------------------------------------------------------------------
///
/// Returns the list of stand-alone parameters.
///
public List<string> Params
{
get { return mParams; }
}
List<string> mParams = new List<string>();
}
//---------------------------------------------------------------------
///
/// Implements command line parsing
///
public class CommandLine
{
//---------------------------------------------------------------------
///
/// Parses the passed command line arguments and returns the result
/// in a CommandArgs object.
///
/// The command line is assumed to be in the format:
///
/// CMD [param] [[-|--|\]<arg>[[=]<value>]] [param]
///
/// Basically, stand-alone parameters can appear anywhere on the command line.
/// Arguments are defined as key/value pairs. The argument key must begin
/// with a '-', '--', or '\'. Between the argument and the value must be at
/// least one space or a single '='. Extra spaces are ignored. Arguments MAY
/// be followed by a value or, if no value supplied, the string 'true' is used.
/// You must enclose argument values in quotes if they contain a space, otherwise
/// they will not parse correctly.
///
/// Example command lines are:
///
/// cmd first -o outfile.txt --compile second \errors=errors.txt third fourth --test = "the value" fifth
///
/// array of command line arguments
///
public static CommandArgs Parse(string[] args)
{
char[] kEqual = new char[] { '=' };
char[] kArgStart = new char[] { '-', '\\' };
CommandArgs ca = new CommandArgs();
int ii = -1;
string token = NextToken(args, ref ii);
while (token != null)
{
if (IsArg(token))
{
string arg = token.TrimStart(kArgStart).TrimEnd(kEqual);
string value = null;
if (arg.Contains("="))
{
// arg was specified with an '=' sign, so we need
// to split the string into the arg and value, but only
// if there is no space between the '=' and the arg and value.
string[] r = arg.Split(kEqual, 2);
if (r.Length == 2 && r[1] != string.Empty)
{
arg = r[0];
value = r[1];
}
}
while (value == null)
{
string next = NextToken(args, ref ii);
if (next != null)
{
if (IsArg(next))
{
// push the token back onto the stack so
// it gets picked up on next pass as an Arg
ii--;
value = "true";
}
else if (next != "=")
{
// save the value (trimming any '=' from the start)
value = next.TrimStart(kEqual);
}
}
}
// save the pair
ca.ArgPairs.Add(arg, value);
}
else if (token != string.Empty)
{
// this is a stand-alone parameter.
ca.Params.Add(token);
}
token = NextToken(args, ref ii);
}
return ca;
}
//---------------------------------------------------------------------
///
/// Returns True if the passed string is an argument (starts with
/// '-', '--', or '\'.)
///
/// the string token to test
///
static bool IsArg(string arg)
{
return (arg.StartsWith("-") || arg.StartsWith("\\"));
}
//---------------------------------------------------------------------
///
/// Returns the next string token in the argument list
///
/// list of string tokens
/// index of the current token in the array
///
static string NextToken(string[] args, ref int ii)
{
ii++; // move to next token
while (ii < args.Length)
{
string cur = args[ii].Trim();
if (cur != string.Empty)
{
// found valid token
return cur;
}
ii++;
}
// failed to get another token
return null;
}
}
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下面使用一个命令行程序来说明如何调用上述解析类，对具体的命令行解析，如下是调用代码。
static void Main(string[] args)
{
CommandArgs commandArg = CommandLine.Parse(args);
List<string> lparams = commandArg.Params;
for (int i = 0; i < lparams.Count; i++)
{
string commandArgString = commandArg.Params[i];
System.Console.WriteLine(commandArgString);
}
Dictionary<string, string> argPairs = commandArg.ArgPairs;
List<string> keys = argPairs.Keys.ToList();
for (int i = 0; i < keys.Count; i++)
{
string strKey = keys[i];
string strValue = argPairs[strKey];
System.Console.WriteLine("Key/Value: " + strKey + "/" + strValue);
}
}
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测试时输入命令行参数“ -cc -dd ee ff -this a -that b ccc=fff bbb=rrrr ”，最后的解析结果请大家自己查看一下。