看代码
internal class Program
{
static void Main(string[] args)
{
try
{
var abc = EnvironmentVarialbeHelper.Get("abc");
if (!string.IsNullOrEmpty(abc))
{
Console.WriteLine(abc);
}
else
{
EnvironmentVarialbeHelper.Set("abc", DateTime.Now.ToString());
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
Console.ReadLine();
}
}
public static class EnvironmentVarialbeHelper
{
public static string Get(string name)
{
return Environment.GetEnvironmentVariable(name, EnvironmentVariableTarget.Machine);
}
/// <summary>
/// (设置系统级环境变量)需要管理员权限
/// </summary>
/// <param name="name"></param>
/// <param name="value"></param>
public static void Set(string name, string value)
{
Environment.SetEnvironmentVariable(name, value, EnvironmentVariableTarget.Machine);
}
}
需要注意
写入需要管理员权限。其他没了