.NET Tutorial - Hello World in 10 minutes
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Intro
Purpose
Install .NET and create your first application.
Prerequisites
None.
Time to Complete
10 minutes
Scenario
A simple application written in C# that prints Hello, World! to the console.
Download and install
To start building .NET apps you just need to download and install the .NET SDK (Software Development Kit).
Not running x64? You'll need to download the .NET Core binaries instead.
Enable .NET channel
In order to install .NET Core from Red Hat on RHEL, you first need to register using the Red Hat Subscription Manager. If this has not been done on your system, or if you are unsure, see the Red Hat Getting Started Guide.
Install the .NET SDK
After registering with the Subscription Manager and enabling the .NET Core channel, you are ready to install and enable the .NET SDK.
In your terminal, run the following commands:
Terminal
yum install rh-dotnet22 -y
scl enable rh-dotnet22 bashRegister Microsoft key and feed
Before installing .NET, you'll need to register the Microsoft key, register the product repository, and install required dependencies. This only needs to be done once per machine.
Open a terminal and run the following commands:
Terminal
wget -q https://packages.microsoft.com/config/ubuntu/19.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
sudo dpkg -i packages-microsoft-prod.debInstall the .NET SDK
Update the products available for installation, then install the .NET SDK.
In your terminal, run the following commands:
Terminal
sudo apt-get install apt-transport-https
sudo apt-get update
sudo apt-get install dotnet-sdk-2.2If you receive an error message similar to Unable to locate package dotnet-sdk-2.2, run the following commands.
Terminal
sudo dpkg --purge packages-microsoft-prod && sudo dpkg -i packages-microsoft-prod.deb
sudo apt-get update
sudo apt-get install dotnet-sdk-2.2If that doesn't work, you can run a manual install with the following commands.
Terminal
sudo apt-get install -y gpg
wget -qO- https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor > microsoft.asc.gpg
sudo mv microsoft.asc.gpg /etc/apt/trusted.gpg.d/
wget -q https://packages.microsoft.com/config/ubuntu/19.04/prod.list
sudo mv prod.list /etc/apt/sources.list.d/microsoft-prod.list
sudo chown root:root /etc/apt/trusted.gpg.d/microsoft.asc.gpg
sudo chown root:root /etc/apt/sources.list.d/microsoft-prod.list
sudo apt-get install -y apt-transport-https
sudo apt-get update
sudo apt-get install dotnet-sdk-2.2Register Microsoft key and feed
Before installing .NET, you'll need to register the Microsoft key, register the product repository, and install required dependencies. This only needs to be done once per machine.
Open a terminal and run the following commands:
Terminal
wget -q https://packages.microsoft.com/config/ubuntu/18.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
sudo dpkg -i packages-microsoft-prod.debInstall the .NET SDK
Update the products available for installation, then install the .NET SDK.
In your terminal, run the following commands:
Terminal
sudo add-apt-repository universe
sudo apt-get install apt-transport-https
sudo apt-get update
sudo apt-get install dotnet-sdk-2.2If you receive an error message similar to Unable to locate package dotnet-sdk-2.2, run the following commands.
Terminal
sudo dpkg --purge packages-microsoft-prod && sudo dpkg -i packages-microsoft-prod.deb
sudo apt-get update
sudo apt-get install dotnet-sdk-2.2If that doesn't work, you can run a manual install with the following commands.
Terminal
sudo apt-get install -y gpg
wget -qO- https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor > microsoft.asc.gpg
sudo mv microsoft.asc.gpg /etc/apt/trusted.gpg.d/
wget -q https://packages.microsoft.com/config/ubuntu/18.04/prod.list
sudo mv prod.list /etc/apt/sources.list.d/microsoft-prod.list
sudo chown root:root /etc/apt/trusted.gpg.d/microsoft.asc.gpg
sudo chown root:root /etc/apt/sources.list.d/microsoft-prod.list
sudo apt-get install -y apt-transport-https
sudo apt-get update
sudo apt-get install dotnet-sdk-2.2Register Microsoft key and feed
Before installing .NET, you'll need to register the Microsoft key, register the product repository, and install required dependencies. This only needs to be done once per machine.
Open a terminal and run the following commands:
Terminal
wget -q https://packages.microsoft.com/config/ubuntu/16.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
sudo dpkg -i packages-microsoft-prod.debInstall the .NET SDK
Update the products available for installation, then install the .NET SDK.
In your terminal, run the following commands:
Terminal
sudo apt-get install apt-transport-https
sudo apt-get update
sudo apt-get install dotnet-sdk-2.2If you later perform an in-place upgrade, you may get an error message similar to Unable to locate package dotnet-sdk-2.2 when trying to install/update .NET.
See Ubuntu 19.04 install instructions to learn how to fix this issue.
Register Microsoft key and feed
Before installing .NET, you'll need to register the Microsoft key, register the product repository, and install required dependencies. This only needs to be done once per machine.
Open a terminal and run the following commands:
Terminal
wget -qO- https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor > microsoft.asc.gpg
sudo mv microsoft.asc.gpg /etc/apt/trusted.gpg.d/
wget -q https://packages.microsoft.com/config/debian/9/prod.list
sudo mv prod.list /etc/apt/sources.list.d/microsoft-prod.list
sudo chown root:root /etc/apt/trusted.gpg.d/microsoft.asc.gpg
sudo chown root:root /etc/apt/sources.list.d/microsoft-prod.listInstall the .NET SDK
Update the products available for installation, then install the .NET SDK.
In your terminal, run the following commands:
Terminal
sudo apt-get install apt-transport-https
sudo apt-get update
sudo apt-get install dotnet-sdk-2.2Add the dotnet product feed
Before installing .NET, you'll need to register the Microsoft key, register the product repository, and install required dependencies. This only needs to be done once per machine.
Open a terminal and run the following commands:
Terminal
sudo rpm --import https://packages.microsoft.com/keys/microsoft.asc
sudo wget -q -O /etc/yum.repos.d/microsoft-prod.repo https://packages.microsoft.com/config/fedora/27/prod.repoInstall the .NET SDK
Update the products available for installation, then install the .NET SDK.
In your terminal, run the following commands:
Terminal
sudo dnf update
sudo dnf install dotnet-sdk-2.2Add the dotnet product feed
Before installing .NET, you'll need to register the Microsoft key, register the product repository, and install required dependencies. This only needs to be done once per machine.
Open a terminal and run the following commands:
Terminal
sudo rpm --import https://packages.microsoft.com/keys/microsoft.asc
sudo wget -q -O /etc/yum.repos.d/microsoft-prod.repo https://packages.microsoft.com/config/fedora/27/prod.repoInstall the .NET SDK
Update the products available for installation, then install the .NET SDK.
In your terminal, run the following commands:
Terminal
sudo dnf update
sudo dnf install dotnet-sdk-2.2Add the dotnet product feed
Before installing .NET, you'll need to register the Microsoft key, register the product repository, and install required dependencies. This only needs to be done once per machine.
Open a terminal and run the following commands:
Terminal
sudo rpm -Uvh https://packages.microsoft.com/config/rhel/7/packages-microsoft-prod.rpmInstall the .NET SDK
Update the products available for installation, then install the .NET SDK.
In your terminal, run the following commands:
Terminal
sudo yum update
sudo yum install dotnet-sdk-2.2Add the dotnet product feed
Before installing .NET, you'll need to register the Microsoft key, register the product repository, and install required dependencies. This only needs to be done once per machine.
Open a terminal and run the following commands:
Terminal
sudo zypper install libicu
sudo rpm --import https://packages.microsoft.com/keys/microsoft.asc
wget -q https://packages.microsoft.com/config/opensuse/42.2/prod.repo
sudo mv prod.repo /etc/zypp/repos.d/microsoft-prod.repo
sudo chown root:root /etc/zypp/repos.d/microsoft-prod.repoInstall the .NET SDK
Update the products available for installation, then install the .NET SDK.
In your terminal, run the following commands:
Terminal
sudo zypper update
sudo zypper install dotnet-sdk-2.2Add the dotnet product feed
Before installing .NET, you'll need to register the Microsoft key, register the product repository, and install required dependencies. This only needs to be done once per machine.
Open a terminal and run the following commands:
Terminal
sudo rpm -Uvh https://packages.microsoft.com/config/sles/12/packages-microsoft-prod.rpmInstall the .NET SDK
Update the products available for installation, then install the .NET SDK.
In your terminal, run the following commands:
Terminal
sudo zypper update
sudo zypper install dotnet-sdk-2.2Check everything installed correctly
Once you've installed, open a new command prompt and run the following command:
Once you've installed, open a new terminal and run the following command:
Command prompt
dotnetIf the command runs, printing out information about how to use dotnet, you're good to go.
If you receive a 'dotnet' is not recognized as an internal or external command error, make sure you opened a new command prompt. If you can't resolve the issue, use the I ran into an issue button to get help fixing the problem.
Create your app
In your command prompt, run the following commands:
In your terminal, run the following commands:
Command prompt
dotnet new console -o myApp
cd myAppThe dotnet command creates a new application of type console for you. The -o parameter creates a directory named myApp where your app is stored, and populates it with the required files. The cd myApp command puts you into the newly created app directory.
The main file in the myApp folder is Program.cs. By default, it already contains the necessary code to write "Hello World!" to the Console.
Program.cs
using System;
namespace myApp
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Hello World!");
}
}
}Run your app
In your command prompt, run the following command:
In your terminal, run the following command:
Command prompt
dotnet runCongratulations, you've built and run your first .NET app!
Edit your code
Open Program.cs in any text editor (e.g. Notepad) and add a new line of code below the one that prints "Hello World!", like the following:
Program.cs (shortened for clarity)
Console.WriteLine("Hello World!");
Console.WriteLine("The current time is " + DateTime.Now);Save the Program.cs file, and run your code again.
Command prompt
dotnet runNext steps
Congratulations, you've built and run your first .NET app!
Keep learning
If you want to keep learning general .NET skills, try our Introduction to C# tutorials.
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