C# How To: CSV to List or List to CSV

The following code snippet shows how to convert from a CSV string to a List using the string class Split method.

const string ColoursCsv = "red,blue,green,yellow";
                        
List<string> coloursList = ColoursCsv.Split(',').ToList();

The following code snippet shows how to convert from a list to a CSV string using the string class Join method.

List<string> coloursList = new List<string> { 
    "red", 
    "blue", 
    "green", 
    "yellow" 
};

string coloursCsv = string.Join(",", coloursList);

C# How To: Convert to Convert String to Int

To convert from a string to an integer type you can use the Convert class as shown in the code snippet below. The Convert class contains a large number of static methods which allow you to convert from one type to another.

string numberString = "1985";
int number = Convert.ToInt32(numberString);

C# How To: Start a Program/Process

To start a program in C#, you can use the Process class. The Process class has a static method called Start which accepts a filename as a parameter. The example below shows how easy it is to start Microsoft Notepad from a C# application. Remember to include the "using System.Diagnostics;" directive at the top.

const string ProgramPath = "Notepad";

Process.Start(ProgramPath);

Note that if you need to start a program which accepts command line arguments, then you can use an overload of the Start method which accepts a ProcessStartInfo object. The following snippet shows how to open a file within notepad from your C# application.

const string ProgramPath = "Notepad";

Process.Start(new ProcessStartInfo
    {
        FileName = ProgramPath,
        Arguments = @"C:\WriteTest.txt"
    }
);

C# How To: Create Text File And Write To It

Continuing with my new C# "how-to" theme, the code snippet below shows how to create a text file and write content to it using the StreamWriter class. Remember to add the "using System.IO;" directive at the top. Note that there is a StreamWriter constructor which supports a Boolean parameter "append" - if you pass true for this parameter and the file already exists, the StreamWriter will append content to the file rather than overwrite the existing content.

const string TextFilePath = @"C:\WriteTest.txt";

using (StreamWriter writer = new StreamWriter(TextFilePath))
{
    writer.WriteLine("Hello, world");
    writer.WriteLine("Bye, world");
}

C# How To: Read a Text File

This is the first of a series of C# "how to" posts. The following C# code snippet shows how to read a text file line-by-line using the StreamReader class. Remember to add the "using System.IO;" directive as this is the namespace which the StreamReader class is in.

const string TextFilePath = @"C:\ReadTest.txt";

using (StreamReader reader = new StreamReader(TextFilePath))
{
    string currentLine;

    while ((currentLine = reader.ReadLine()) != null)
    {
        Console.WriteLine(currentLine);
    }
}