var diff = InlineDiffBuilder.Diff(before, after);

var savedColor = Console.ForegroundColor;
foreach (var line in diff.Lines)
{
    switch (line.Type)
    {
        case ChangeType.Inserted:
            Console.ForegroundColor = ConsoleColor.Green;
            Console.Write("+ ");
            break;
        case ChangeType.Deleted:
            Console.ForegroundColor = ConsoleColor.Red;
            Console.Write("- ");
            break;
        default:
            Console.ForegroundColor = ConsoleColor.Gray; // compromise for dark or light background
            Console.Write("  ");
            break;
    }

    Console.WriteLine(line.Text);
}
Console.ForegroundColor = savedColor;

/// <summary>
/// Provides methods for generate differences between texts
/// </summary>
public interface IDiffer
{
    /// <summary>
    /// Create a diff by comparing text line by line
    /// </summary>
    /// <param name="oldText">The old text.</param>
    /// <param name="newText">The new text.</param>
    /// <param name="ignoreWhiteSpace">if set to <c>true</c> will ignore white space when determining if lines are the same.</param>
    /// <returns>A DiffResult object which details the differences</returns>
    DiffResult CreateLineDiffs(string oldText, string newText, bool ignoreWhiteSpace);

    /// <summary>
    /// Create a diff by comparing text character by character
    /// </summary>
    /// <param name="oldText">The old text.</param>
    /// <param name="newText">The new text.</param>
    /// <param name="ignoreWhitespace">if set to <c>true</c> will treat all whitespace characters are empty strings.</param>
    /// <returns>A DiffResult object which details the differences</returns>
    DiffResult CreateCharacterDiffs(string oldText, string newText, bool ignoreWhitespace);

    /// <summary>
    /// Create a diff by comparing text word by word
    /// </summary>
    /// <param name="oldText">The old text.</param>
    /// <param name="newText">The new text.</param>
    /// <param name="ignoreWhitespace">if set to <c>true</c> will ignore white space when determining if words are the same.</param>
    /// <param name="separators">The list of characters which define word separators.</param>
    /// <returns>A DiffResult object which details the differences</returns>
    DiffResult CreateWordDiffs(string oldText, string newText, bool ignoreWhitespace, char[] separators);

    /// <summary>
    /// Create a diff by comparing text in chunks determined by the supplied chunker function.
    /// </summary>
    /// <param name="oldText">The old text.</param>
    /// <param name="newText">The new text.</param>
    /// <param name="ignoreWhiteSpace">if set to <c>true</c> will ignore white space when determining if chunks are the same.</param>
    /// <param name="chunker">A function that will break the text into chunks.</param>
    /// <returns>A DiffResult object which details the differences</returns>
    DiffResult CreateCustomDiffs(string oldText, string newText, bool ignoreWhiteSpace, Func<string, string[]> chunker);

            /// <summary>
        /// Create a diff by comparing text line by line
        /// </summary>
        /// <param name="oldText">The old text.</param>
        /// <param name="newText">The new text.</param>
        /// <param name="ignoreWhiteSpace">if set to <c>true</c> will ignore white space when determining if lines are the same.</param>
        /// <param name="ignoreCase">Determine if the text comparision is case sensitive or not</param>
        /// <param name="chunker">Component responsible for tokenizing the compared texts</param>
        /// <returns>A DiffResult object which details the differences</returns>
        DiffResult CreateDiffs(string oldText, string newText, bool ignoreWhiteSpace, bool ignoreCase, IChunker chunker);
}

public interface IChunker
{
    /// <summary>
    /// Dive text into sub-parts
    /// </summary>
    string[] Chunk(string text);
}

/// <summary>
/// Provides methods that generate differences between texts for displaying in a side by side view.
/// </summary>
public interface ISideBySideDiffBuilder
{
    /// <summary>
    /// Builds a diff model for  displaying diffs in a side by side view
    /// </summary>
    /// <param name="oldText">The old text.</param>
    /// <param name="newText">The new text.</param>
    /// <returns>The side by side diff model</returns>
    SideBySideDiffModel BuildDiffModel(string oldText, string newText);
}

using DiffPlex.UI;

DiffView.SetText(OldText, NewText);

// true if it is in split view; otherwise, false, in unified view.
public bool IsSplitView { get; set; }

// true if it is in unified view; otherwise, false, in split view.
public bool IsUnifiedView { get; set; }

// The selection mode of list view. Default is None.
public ListViewSelectionMode SelectionMode { get; set; }

// true if ignore white spaces; otherwise, false. Default is true.
public bool IgnoreWhiteSpace { get; set; }

// true if the text is case sensitive; otherwise, false. Default is false.
public bool IsCaseSensitive { get; set; }

// The default text color (foreground brush).
public Brush Foreground { get; set; }

// The background.
public Brush Background { get; set; }

// The width of the line number. Default is 50.
public GridLength LineNumberWidth { get; set; }

// The style of the line number.
public Style LineNumberStyle { get; set; }

// The width of the change type symbol. Default is 20.
public GridLength ChangeTypeWidth { get; set; }

// The style of the change type symbol.
public Style ChangeTypeStyle { get; set; }

// The style of the text.
public Style TextStyle { get; set; }

// true if the text is selection enabled; otherwise, false. Default is true.
public bool IsTextSelectionEnabled { get; set; }

// true if collapse unchanged sections; otherwise, false. Default is false.
public bool IsUnchangedSectionCollapsed { get; set; }

// The lines for context. Default is 2.
public int LineCountForContext { get; set; }

// true if the file selector menu button is enabled; otherwise, false. Default is true.
public bool IsFileMenuEnabled { get; set; }

// The height of command bar. Default is 50.
public GridLength CommandBarHeight { get; set; }

// The default label position of command bar. Default is Right.
public CommandBarDefaultLabelPosition CommandLabelPosition { get; set; }

// The collection of secondary command elements for the command bar.
public IObservableVector<ICommandBarElement> SecondaryCommands { get; }

using DiffPlex.Wpf.Controls;

DiffView.OldText = oldText;
DiffView.NewText = newText;

// The header of old text.
public string OldTextHeader { get; set; }

// The header of new text.
public string NewTextHeader { get; set; }

// true if it is in side-by-side (split) view;
// otherwise, false, in inline (unified) view.
public bool IsSideBySideViewMode { get; }

// true if collapse unchanged sections; otherwise, false.
public bool IgnoreUnchanged { get; set; }

// The font size.
public double FontSize { get; set; }

// The preferred font family.
public FontFamily FontFamily { get; set; }

// The font weight.
public FontWeight FontWeight { get; set; }

// The font style.
public FontStyle FontStyle { get; set; }

// The font-stretching characteristics.
public FontStretch FontStretch { get; set; }

// The default text color (foreground brush).
public Brush Foreground { get; set; }

// The background brush of the line inserted.
public Brush InsertedBackground { get; set; }

// The background brush of the line deleted.
public Brush DeletedBackground { get; set; }

// The text color (foreground brush) of the line number.
public Brush LineNumberForeground { get; set; }

// The width of the line number and change type symbol.
public int LineNumberWidth { get; set; }

// The background brush of the line imaginary.
public Brush ImaginaryBackground { get; set; }

// The text color (foreground brush) of the change type symbol.
public Brush ChangeTypeForeground { get; set; }

// The background brush of the header.
public Brush HeaderBackground { get; set; }

// The height of the header.
public double HeaderHeight { get; set; }

// The background brush of the grid splitter.
public Brush SplitterBackground { get; set; }

// The width of the grid splitter.
public Thickness SplitterWidth { get; set; }

// A value that represents the actual calculated width of the left side panel.
public double LeftSideActualWidth { get; }

// A value that represents the actual calculated width of the right side panel.
public double RightSideActualWidth { get; }

// Occurs when the grid splitter loses mouse capture.
public event DragCompletedEventHandler SplitterDragCompleted;

// Occurs one or more times as the mouse changes position when the grid splitter has logical focus and mouse capture.
public event DragDeltaEventHandler SplitterDragDelta;

// Occurs when the grid splitter receives logical focus and mouse capture.
public event DragStartedEventHandler SplitterDragStarted;

// Occurs when the view mode is changed.
public event EventHandler<ViewModeChangedEventArgs> ViewModeChanged;

using DiffPlex.WindowsForms.Controls;

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();

        var diffView = new DiffViewer
        {
            Margin = new Padding(0),
            Dock = DockStyle.Fill,
            OldText = oldText,
            NewText = newText
        };
        Controls.Add(diffView);
    }
}

// The header of old text.
public string OldTextHeader { get; set; }

// The header of new text.
public string NewTextHeader { get; set; }

// true if it is in side-by-side (split) view;
// otherwise, false, in inline (unified) view.
public bool IsSideBySideViewMode { get; }

// true if collapse unchanged sections; otherwise, false.
public bool IgnoreUnchanged { get; set; }

// The font size.
public double FontSize { get; set; }

// The preferred font family names in string.
public string FontFamilyNames { get; set; }

// The font weight.
public int FontWeight { get; set; }

// The font style.
public bool IsFontItalic { get; set; }

// The default text color (foreground brush).
public Color ForeColor { get; set; }

// The background brush of the line inserted.
public Color InsertedBackColor { get; set; }

// The background brush of the line deleted.
public Color DeletedBackColor { get; set; }

// The text color (foreground color) of the line number.
public Color LineNumberForeColor { get; set; }

// The width of the line number and change type symbol.
public int LineNumberWidth { get; set; }

// The background brush of the line imaginary.
public Color ImaginaryBackColor { get; set; }

// The text color (foreground color) of the change type symbol.
public Color ChangeTypeForeColor { get; set; }

// The background brush of the header.
public Color HeaderBackColor { get; set; }

// The height of the header.
public double HeaderHeight { get; set; }

// The background brush of the grid splitter.
public Color SplitterBackColor { get; set; }

// The width of the grid splitter.
public Padding SplitterWidth { get; set; }

// A value that represents the actual calculated width of the left side panel.
public double LeftSideActualWidth { get; }

// A value that represents the actual calculated width of the right side panel.
public double RightSideActualWidth { get; }