C#中如何获取系统环境变量

时间：2011-01-26 来源：Pegasus923

以下语句得到%systemdrive%的值，即“C:”

string sPath = Environment.GetEnvironmentVariable("systemdrive")

1 string sPath = Environment.GetEnvironmentVariable("systemdrive");
2 Console.WriteLine(sPath);
3 
4  //C:

以下是MSDN上Environment Class的Sample code。

http://msdn.microsoft.com/en-us/library/system.environment.aspx

Sample for Environment class summary

  1 using System;
  2  using System.Collections;
  3 
  4  class Sample 
  5 {
  6     public static void Main() 
  7     {
  8     String str;
  9     String nl = Environment.NewLine;
 10  //
 11      Console.WriteLine();
 12     Console.WriteLine("-- Environment members --");
 13 
 14  //  Invoke this sample with an arbitrary set of command line arguments.
 15      Console.WriteLine("CommandLine: {0}", Environment.CommandLine);
 16 
 17     String[] arguments = Environment.GetCommandLineArgs();
 18     Console.WriteLine("GetCommandLineArgs: {0}", String.Join(", ", arguments));
 19 
 20 //  <-- Keep this information secure! -->
 21     Console.WriteLine("CurrentDirectory: {0}", Environment.CurrentDirectory);
 22 
 23     Console.WriteLine("ExitCode: {0}", Environment.ExitCode);
 24 
 25     Console.WriteLine("HasShutdownStarted: {0}", Environment.HasShutdownStarted);
 26 
 27 //  <-- Keep this information secure! -->
 28     Console.WriteLine("MachineName: {0}", Environment.MachineName);
 29 
 30     Console.WriteLine("NewLine: {0}  first line{0}  second line{0}  third line",
 31                           Environment.NewLine);
 32 
 33     Console.WriteLine("OSVersion: {0}", Environment.OSVersion.ToString());
 34 
 35     Console.WriteLine("StackTrace: '{0}'", Environment.StackTrace);
 36 
 37 //  <-- Keep this information secure! -->
 38     Console.WriteLine("SystemDirectory: {0}", Environment.SystemDirectory);
 39 
 40     Console.WriteLine("TickCount: {0}", Environment.TickCount);
 41 
 42 //  <-- Keep this information secure! -->
 43     Console.WriteLine("UserDomainName: {0}", Environment.UserDomainName);
 44 
 45     Console.WriteLine("UserInteractive: {0}", Environment.UserInteractive);
 46 
 47 //  <-- Keep this information secure! -->
 48     Console.WriteLine("UserName: {0}", Environment.UserName);
 49 
 50     Console.WriteLine("Version: {0}", Environment.Version.ToString());
 51 
 52     Console.WriteLine("WorkingSet: {0}", Environment.WorkingSet);
 53 
 54 //  No example for Exit(exitCode) because doing so would terminate this example.
 55 
 56 //  <-- Keep this information secure! -->
 57     String query = "My system drive is %SystemDrive% and my system root is %SystemRoot%";
 58     str = Environment.ExpandEnvironmentVariables(query);
 59     Console.WriteLine("ExpandEnvironmentVariables: {0}  {1}", nl, str);
 60 
 61     Console.WriteLine("GetEnvironmentVariable: {0}  My temporary directory is {1}.", nl,
 62                            Environment.GetEnvironmentVariable("TEMP"));
 63 
 64     Console.WriteLine("GetEnvironmentVariables: ");
 65     IDictionary    environmentVariables = Environment.GetEnvironmentVariables();
 66     foreach (DictionaryEntry de in environmentVariables)
 67         {
 68         Console.WriteLine("  {0} = {1}", de.Key, de.Value);
 69         }
 70 
 71     Console.WriteLine("GetFolderPath: {0}", 
 72                  Environment.GetFolderPath(Environment.SpecialFolder.System));
 73 
 74     String[] drives = Environment.GetLogicalDrives();
 75     Console.WriteLine("GetLogicalDrives: {0}", String.Join(", ", drives));
 76     }
 77 }
 78 /*
 79 This example produces results similar to the following:
 80 (Any result that is lengthy or reveals information that should remain 
 81 secure has been omitted and marked "!---OMITTED---!".)
 82 
 83 C:\>env0 ARBITRARY TEXT
 84 
 85 -- Environment members --
 86 CommandLine: env0 ARBITRARY TEXT
 87 GetCommandLineArgs: env0, ARBITRARY, TEXT
 88 CurrentDirectory: C:\Documents and Settings\!---OMITTED---!
 89 ExitCode: 0
 90 HasShutdownStarted: False
 91 MachineName: !---OMITTED---!
 92 NewLine:
 93   first line
 94   second line
 95   third line
 96 OSVersion: Microsoft Windows NT 5.1.2600.0
 97 StackTrace: '   at System.Environment.GetStackTrace(Exception e)
 98    at System.Environment.GetStackTrace(Exception e)
 99    at System.Environment.get_StackTrace()
100    at Sample.Main()'
101 SystemDirectory: C:\WINNT\System32
102 TickCount: 17995355
103 UserDomainName: !---OMITTED---!
104 UserInteractive: True
105 UserName: !---OMITTED---!
106 Version: !---OMITTED---!
107 WorkingSet: 5038080
108 ExpandEnvironmentVariables:
109   My system drive is C: and my system root is C:\WINNT
110 GetEnvironmentVariable:
111   My temporary directory is C:\DOCUME~1\!---OMITTED---!\LOCALS~1\Temp.
112 GetEnvironmentVariables: 
113   !---OMITTED---!
114 GetFolderPath: C:\WINNT\System32
115 GetLogicalDrives: A:\, C:\, D:\
116 
117 */