FindReplaceDirection

FindReplaceDirection enumeration

Specifies direction for replace operations.

public enum FindReplaceDirection

Values

NameValueDescription
Forward0Matched items are replaced from first to last.
Backward1Matched items are replaced from last back to first.

Examples

Shows how to determine which direction a find-and-replace operation traverses the document in.

public void Direction(FindReplaceDirection findReplaceDirection)
{
    Document doc = new Document();
    DocumentBuilder builder = new DocumentBuilder(doc);

    // Insert three runs which we can search for using a regex pattern.
    // Place one of those runs inside a text box.
    builder.Writeln("Match 1.");
    builder.Writeln("Match 2.");
    builder.Writeln("Match 3.");
    builder.Writeln("Match 4.");

    // We can use a "FindReplaceOptions" object to modify the find-and-replace process.
    FindReplaceOptions options = new FindReplaceOptions();

    // Assign a custom callback to the "ReplacingCallback" property.
    TextReplacementRecorder callback = new TextReplacementRecorder();
    options.ReplacingCallback = callback;

    // Set the "Direction" property to "FindReplaceDirection.Backward" to get the find-and-replace
    // operation to start from the end of the range, and traverse back to the beginning.
    // Set the "Direction" property to "FindReplaceDirection.Forward" to get the find-and-replace
    // operation to start from the beginning of the range, and traverse to the end.
    options.Direction = findReplaceDirection;

    doc.Range.Replace(new Regex(@"Match \d*"), "Replacement", options);

    Assert.AreEqual("Replacement.\r" +
                    "Replacement.\r" +
                    "Replacement.\r" +
                    "Replacement.", doc.GetText().Trim());

    switch (findReplaceDirection)
    {
        case FindReplaceDirection.Forward:
            Assert.AreEqual(new[] { "Match 1", "Match 2", "Match 3", "Match 4" }, callback.Matches);
            break;
        case FindReplaceDirection.Backward:
            Assert.AreEqual(new[] { "Match 4", "Match 3", "Match 2", "Match 1" }, callback.Matches);
            break;
    }
}

/// <summary>
/// Records all matches that occur during a find-and-replace operation in the order that they take place.
/// </summary>
private class TextReplacementRecorder : IReplacingCallback
{
    ReplaceAction IReplacingCallback.Replacing(ReplacingArgs e)
    {
        Matches.Add(e.Match.Value);
        return ReplaceAction.Replace;
    }

    public List<string> Matches { get; } = new List<string>();
}

See Also

FindReplaceOptions Class