Simple MsBuild Custom Task

Here's a very simple custom task that reads in the number in a text file (which only contains a number) increments, passes it back out to the calling MsBuild, and then writes the new value to the text file.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Build.Framework;
using Microsoft.Build.Utilities;
 
namespace BMsBuildTasks
{
  public class IncrementerTask:Task
  {
    [Output]
    public ITaskItem OutputFullPath { get; set; }
    [Output]
    public int Value { get; set; }
    public override bool Execute( )
    {
      
      var path =OutputFullPath==null?OutputFullPath.GetWellKnownMetaData(WellKnownMetaData35.FullPath ):
        @"c:\temp\version.txt";
 
      int value;
      using (var file=new System.IO.StreamReader(path))
      {
        
        if (!int.TryParse(file.ReadToEnd( ), out value))
          return false;
 
      }
      value++;
      Value=value;
      using (var file=new System.IO.StreamWriter(path,false))
      {
        file.Write(value);
 
      }
      OutputFullPath = new TaskItem(path);
      return true;
    }
  }
}

    public static string GetWellKnownMetaData(this ITaskItem item, WellKnownMetaData35 value)
    {
      return item.GetMetadata(value.ToString( ));
    }

public enum WellKnownMetaData35
  {
    FullPath,
    RootDir,
    Filename,
    Extension,
    RelativeDir,
    Directory,
    RecursiveDir,
    Identity,
    ModifiedTime,
    CreatedTime,
    AccessedTime
  }