Clear

BookmarksOutlineLevelCollection.Clear method

Removes all elements from the collection.

public void Clear()

Examples

Shows how to set outline levels for bookmarks.

Document doc = new Document();
DocumentBuilder builder = new DocumentBuilder(doc);

// Insert a bookmark with another bookmark nested inside it.
builder.StartBookmark("Bookmark 1");
builder.Writeln("Text inside Bookmark 1.");

builder.StartBookmark("Bookmark 2");
builder.Writeln("Text inside Bookmark 1 and 2.");
builder.EndBookmark("Bookmark 2");

builder.Writeln("Text inside Bookmark 1.");
builder.EndBookmark("Bookmark 1");

// Insert another bookmark.
builder.StartBookmark("Bookmark 3");
builder.Writeln("Text inside Bookmark 3.");
builder.EndBookmark("Bookmark 3");

// When saving to .pdf, bookmarks can be accessed via a drop-down menu and used as anchors by most readers.
// Bookmarks can also have numeric values for outline levels,
// enabling lower level outline entries to hide higher-level child entries when collapsed in the reader.
PdfSaveOptions pdfSaveOptions = new PdfSaveOptions();
BookmarksOutlineLevelCollection outlineLevels = pdfSaveOptions.OutlineOptions.BookmarksOutlineLevels;

outlineLevels.Add("Bookmark 1", 1);
outlineLevels.Add("Bookmark 2", 2);
outlineLevels.Add("Bookmark 3", 3);

Assert.AreEqual(3, outlineLevels.Count);
Assert.True(outlineLevels.Contains("Bookmark 1"));
Assert.AreEqual(1, outlineLevels[0]);
Assert.AreEqual(2, outlineLevels["Bookmark 2"]);
Assert.AreEqual(2, outlineLevels.IndexOfKey("Bookmark 3"));

// We can remove two elements so that only the outline level designation for "Bookmark 1" is left.
outlineLevels.RemoveAt(2);
outlineLevels.Remove("Bookmark 2");

// There are nine outline levels. Their numbering will be optimized during the save operation.
// In this case, levels "5" and "9" will become "2" and "3".
outlineLevels.Add("Bookmark 2", 5);
outlineLevels.Add("Bookmark 3", 9);

doc.Save(ArtifactsDir + "BookmarksOutlineLevelCollection.BookmarkLevels.pdf", pdfSaveOptions);

// Emptying this collection will preserve the bookmarks and put them all on the same outline level.
outlineLevels.Clear();

See Also

BookmarksOutlineLevelCollection.Add BookmarksOutlineLevelCollection.Contains