Using Add-Type

23 Feb 2025 - jhunter

Sources

`Get-Help Add-Type -examples

Command

Add-Type -TypeDefinition $code -Language CSharp

Definition

Make c# code available inside Powershell.

Add-Type is very handy because it expands the possibilities of powershell coding. PowerShell is a scripting language and c# is a compiled langugage.

Using Add-Type lets me study c# without having to create an entire program project.

Options

-TypeDefinition is followed by a string of c# code. -Language is not required it seems according to the help, but is used to defined that the assembly type will be c#.

Example

Move a cursor

$code = @"
using System;
using System.Threading;

namespace moving_dot{
	public class Program{
		public static void Main(){
                        Int32 initial_x = Console.CursorLeft;
			Int32 initial_y = Console.CursorTop;			
			Int32 Length_bar1 = 25;
			Console.CursorVisible=false;

			for(int i = 0; i < 180 ; i++){
				if ((i % (Length_bar1 * 2)) >= Length_bar1){
					for(int j = 0; j < ((2* Length_bar1)- (i % (Length_bar1 *2))); j++){
						if(j > 0){
							Console.Write(" ");
						}
					}
					Console.Write(".");
				}
				else if(i % Length_bar1 == 0){
				}
				else{
					for(int j = 0; j < (i % Length_bar1); j++){
						if(j > 0){
							Console.Write(" ");
						}
					}
					Console.Write(".");
				}

				Thread.Sleep(30);


				if ((i % (Length_bar1*2)) >= Length_bar1){
					for(int j = 0; j < ((2* Length_bar1)- (i % (Length_bar1 *2))); j++){
						if(j == 0){
							Console.Write("\b \b");
						}
						else{
							Console.Write("\b");
						}
					}
				}
				else if(i % Length_bar1 == 0){
				}
				else{
					for(int j = 0; j < (i % Length_bar1); j++){
						if(j == 0){
							Console.Write("\b \b");
						}
						else{
							Console.Write("\b");
						}		
					}
				}
			}

			//back to the original place
			Console.SetCursorPosition(initial_x, initial_y);
			Console.CursorVisible=true;
		}
	}
}
"@

Add-Type -TypeDefinition $code -Language CSharp

[moving_dot.Program]::Main()

Troubleshooting

Sadly you can’t always copy and paste c# code directly into PowerShell in this manner. The terminal will helpfully say which parts of the c# code are invalid.

In my tests, I used these lines in c#:

Int32 initial_x = Console.GetCursorPosition().Left;
Int32 initial_y = Console.GetCursorPosition().Top;

But I needed to replace those lines with the following code in PowerShell:

Int32 initial_x = Console.CursorLeft;
Int32 initial_y = Console.CursorTop;

You can test with methods are easily available in PowerShell. To investigate cursor commands with the console, I wrote this and then press tab repeadedly to see which methods appeared.

[console]::*cursor*

You can get everything at once thanks to Get-Member:

[console] | Get-Member