Item

BuildingBlockCollection indexer

Retrieves a building block at the given index.

public BuildingBlock this[int index] { get; }
ParameterDescription
indexAn index into the list of building blocks.

Remarks

The index is zero-based.

Negative indexes are allowed and indicate access from the back of the collection. For example -1 means the last item, -2 means the second before last and so on.

If index is greater than or equal to the number of items in the list, this returns a null reference.

If index is negative and its absolute value is greater than the number of items in the list, this returns a null reference.

Examples

Shows ways of accessing building blocks in a glossary document.

public void GlossaryDocument()
{
    Document doc = new Document();
    GlossaryDocument glossaryDoc = new GlossaryDocument();

    BuildingBlock child1 = new BuildingBlock(glossaryDoc) { Name = "Block 1" };
    glossaryDoc.AppendChild(child1);
    BuildingBlock child2 = new BuildingBlock(glossaryDoc) { Name = "Block 2" };
    glossaryDoc.AppendChild(child2);
    BuildingBlock child3 = new BuildingBlock(glossaryDoc) { Name = "Block 3" };
    glossaryDoc.AppendChild(child3);
    BuildingBlock child4 = new BuildingBlock(glossaryDoc) { Name = "Block 4" };
    glossaryDoc.AppendChild(child4);
    BuildingBlock child5 = new BuildingBlock(glossaryDoc) { Name = "Block 5" };
    glossaryDoc.AppendChild(child5);

    Assert.AreEqual(5, glossaryDoc.BuildingBlocks.Count);

    doc.GlossaryDocument = glossaryDoc;

    // There are various ways of accessing building blocks.
    // 1 -  Get the first/last building blocks in the collection:
    Assert.AreEqual("Block 1", glossaryDoc.FirstBuildingBlock.Name);
    Assert.AreEqual("Block 5", glossaryDoc.LastBuildingBlock.Name);

    // 2 -  Get a building block by index:
    Assert.AreEqual("Block 2", glossaryDoc.BuildingBlocks[1].Name);
    Assert.AreEqual("Block 3", glossaryDoc.BuildingBlocks.ToArray()[2].Name);

    // 3 -  Get the first building block that matches a gallery, name and category:
    Assert.AreEqual("Block 4", 
        glossaryDoc.GetBuildingBlock(BuildingBlockGallery.All, "(Empty Category)", "Block 4").Name);

    // We will do that using a custom visitor,
    // which will give every BuildingBlock in the GlossaryDocument a unique GUID
    GlossaryDocVisitor visitor = new GlossaryDocVisitor();
    // Visit start/end of the Glossary document.
    glossaryDoc.Accept(visitor);
    // Visit only start of the Glossary document.
    glossaryDoc.AcceptStart(visitor);
    // Visit only end of the Glossary document.
    glossaryDoc.AcceptEnd(visitor);
    Console.WriteLine(visitor.GetText());

    // In Microsoft Word, we can access the building blocks via "Insert" -> "Quick Parts" -> "Building Blocks Organizer".
    doc.Save(ArtifactsDir + "BuildingBlocks.GlossaryDocument.dotx"); 
}

/// <summary>
/// Gives each building block in a visited glossary document a unique GUID.
/// Stores the GUID-building block pairs in a dictionary.
/// </summary>
public class GlossaryDocVisitor : DocumentVisitor
{
    public GlossaryDocVisitor()
    {
        mBlocksByGuid = new Dictionary<Guid, BuildingBlock>();
        mBuilder = new StringBuilder();
    }

    public string GetText()
    {
        return mBuilder.ToString();
    }

    public Dictionary<Guid, BuildingBlock> GetDictionary()
    {
        return mBlocksByGuid;
    }

    public override VisitorAction VisitGlossaryDocumentStart(GlossaryDocument glossary)
    {
        mBuilder.AppendLine("Glossary document found!");
        return VisitorAction.Continue;
    }

    public override VisitorAction VisitGlossaryDocumentEnd(GlossaryDocument glossary)
    {
        mBuilder.AppendLine("Reached end of glossary!");
        mBuilder.AppendLine("BuildingBlocks found: " + mBlocksByGuid.Count);
        return VisitorAction.Continue;
    }

    public override VisitorAction VisitBuildingBlockStart(BuildingBlock block)
    {
        block.Guid = Guid.NewGuid();
        mBlocksByGuid.Add(block.Guid, block);
        return VisitorAction.Continue;
    }

    public override VisitorAction VisitBuildingBlockEnd(BuildingBlock block)
    {
        mBuilder.AppendLine("\tVisited block \"" + block.Name + "\"");
        mBuilder.AppendLine("\t Type: " + block.Type);
        mBuilder.AppendLine("\t Gallery: " + block.Gallery);
        mBuilder.AppendLine("\t Behavior: " + block.Behavior);
        mBuilder.AppendLine("\t Description: " + block.Description);

        return VisitorAction.Continue;
    }

    private readonly Dictionary<Guid, BuildingBlock> mBlocksByGuid;
    private readonly StringBuilder mBuilder;
}

See Also

BuildingBlockCollection.ToArray