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C# program displays the use of the GetEnvironmentVariable() method of the environment class

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2023-09-09 20:13:021434browse

C# 程序显示环境类的 GetEnvironmentVariable() 方法的使用

In C#, the GetEnvironmentVariable() method of the Environment class is used to obtain the value of the environment variable. It is a useful method for retrieving system-wide and user-specific environment variables. In this article, we will discuss the usage of GetEnvironmentVariable() method and understand how to use it in C# program.

What is the GetEnvironmentVariable() method?

The GetEnvironmentVariable() method is a static method of the Environment class in C#. It takes the name of the environment variable as a string and returns the variable's value as a string. If the environment variable does not exist, null is returned.

GetEnvironmentVariable() method syntax

public static string GetEnvironmentVariable(string variableName)

Example: Use the GetEnvironmentVariable() method to obtain the value of the environment variable

Let's look at an example that demonstrates how to use the GetEnvironmentVariable() method to get the value of an environment variable.

string path = Environment.GetEnvironmentVariable("Path");
Console.WriteLine("Path: " + path);

In this code, we use the GetEnvironmentVariable() method to get the value of the "Path" environment variable.

Example: Use the GetEnvironmentVariable() method to obtain the value of a custom environment variable

Now, let's look at an example that demonstrates how to use the GetEnvironmentVariable() method to retrieve the value of a custom environment variable.

using System;

class Program {
   static void Main() {
      string customVariable = Environment.GetEnvironmentVariable("CustomVariable");
   
      if (!string.IsNullOrEmpty(customVariable)) {
         Console.WriteLine("CustomVariable: " + customVariable);
      } else {
         Console.WriteLine("CustomVariable does not exist");
      }
   }
}

Output

CustomVariable does not exist

In this code, we use the GetEnvironmentVariable() method to retrieve the value of the custom environment variable "CustomVariable". We then print the variable's value to the console. If the variable does not exist, a message indicating that the variable does not exist is output.

in conclusion

The GetEnvironmentVariable() method of the Environment class is a powerful method that can be used to retrieve the value of an environment variable in C#. In this article, we discussed the usage of GetEnvironmentVariable() method and saw how it can be used in C# programs to get the values ​​of system-wide and user-specific environment variables.

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