StringWriter. This C# type is used with HtmlTextWriter. A StringWriter instance is required in the constructor. It helps with building up a string.

C# type notes. In code that uses StringWriter, you can also use the internal StringBuilder. This allows you to convert method return values to string types.

StringReader

StringBuilder

Example. Let's begin by looking at a program that uses StringWriter. This type is implemented with an internal StringBuilder, giving it excellent performance.

HtmlTextWriter

using System;
using System.IO;
using System.Text;
using System.Web.UI;

class Program
{
    static void Main()
    {
        // Example string data
        string[] arr = new string[]
        {
            "One",
            "Two",
            "Three"
        };
        // Write markup and strings to StringWriter
        StringWriter stringWriter = new StringWriter();
        using (HtmlTextWriter writer = new HtmlTextWriter(stringWriter))
        {
            foreach (string item in arr)
            {
                writer.RenderBeginTag(HtmlTextWriterTag.Div);
                // Send internal StringBuilder to markup method.
                WriteMarkup(item, stringWriter.GetStringBuilder());
                writer.RenderEndTag();
            }
        }
        Console.WriteLine(stringWriter.ToString());
    }

    /// <summary>
    /// Writes to StringBuilder parameter
    /// </summary>
    static void WriteMarkup(string sourceString, StringBuilder builder)
    {
        builder.Append("Some").Append(" text");
    }
}
<div>
Some text
</div><div>
Some text
</div><div>
Some text
</div>

StringBuilder. We have shown that using StringBuilder as an argument is an excellent approach. There are minimal wasted CPU cycles due to excessive object creation.

Summary. We saw an example of StringWriter. When working with a buffer or StringBuilder, it is a good idea to always write to the same buffer. We try to avoid creating temporary strings.