C# Block.Reposition方法代码示例

        // --------------------------------------------------------------------
        //
        // Internal Methods
        //
        // --------------------------------------------------------------------

        #region Internal Methods

        /// <summary>
        /// Merges two paragraphs followinng one another.
        /// The content of a second paragraph is moved into the end
        /// of the first one.
        /// </summary>
        /// <param name="firstParagraphOrBlockUIContainer">
        /// First of two merged paragraphs or BlockUIContainer.
        /// </param>
        /// <param name="secondParagraphOrBlockUIContainer">
        /// Second of two mered paragraphs or BlockUIContainer.
        /// </param>
        /// <returns>
        /// true if paragraphs have been merged; false if no actions where made.
        /// </returns>
        internal static bool MergeParagraphs(Block firstParagraphOrBlockUIContainer, Block secondParagraphOrBlockUIContainer)
        {
            if (!ParagraphsAreMergeable(firstParagraphOrBlockUIContainer, secondParagraphOrBlockUIContainer))
            {
                return false; // Cannot mearge these paragraphs.
            }

            // Store parent list item of a second paragraph -
            // to correct its structure after the merge
            ListItem secondListItem = secondParagraphOrBlockUIContainer.PreviousBlock == null ? secondParagraphOrBlockUIContainer.Parent as ListItem : null;

            if (secondListItem != null && secondListItem.PreviousListItem == null && secondParagraphOrBlockUIContainer.NextBlock is List)
            {
                // The second paragraph is a first list item in some list.
                // It has a sublists in it, so this sublist must be unindented
                // to avoid double bulleted line.
                List sublistOfSecondParagraph = (List)secondParagraphOrBlockUIContainer.NextBlock;
                if (sublistOfSecondParagraph.ElementEnd.CompareTo(secondListItem.ContentEnd) == 0)
                {
                    secondListItem.Reposition(null, null);
                }
                else
                {
                    secondListItem.Reposition(sublistOfSecondParagraph.ElementEnd, secondListItem.ContentEnd);
                }
                // At this point the schema is temporaty broken: the secondParagraph and the sublistOfSecondParagraph have List as a parent
                sublistOfSecondParagraph.Reposition(null, null);
                // The schema is repared as to sublistOfSecondParagraph concern, but still broken for secondParagraph - must be corrected in the following code
            }

            // Move the second paragraph out of its wrappers separating from the first paragraph (if any).
            // We can not use RepositionWithContent because it would destroy
            // all pointers and ranges within a moved paragraph.
            // Instead we reposition elements around the two paragraphs.
            while (secondParagraphOrBlockUIContainer.ElementStart.GetPointerContext(LogicalDirection.Backward) == TextPointerContext.ElementStart)
            {
                TextElement parentBlock = (TextElement)secondParagraphOrBlockUIContainer.Parent; 
                Invariant.Assert(parentBlock != null);
                Invariant.Assert(TextSchema.AllowsParagraphMerging(parentBlock.GetType()));

                if (secondParagraphOrBlockUIContainer.ElementEnd.CompareTo(parentBlock.ContentEnd) == 0)
                {
                    // Remove ancestor block if it becomes empty
                    parentBlock.Reposition(null, null);
                }
                else
                {
                    // Move ancestor's Start after the end of our paragraph
                    parentBlock.Reposition(secondParagraphOrBlockUIContainer.ElementEnd, parentBlock.ContentEnd);
                }
            }

            // Store a position after the second paragraph where list merging may be needed
            TextPointer positionAfterSecondParagraph = secondParagraphOrBlockUIContainer.ElementEnd.GetFrozenPointer(LogicalDirection.Forward);

            // Move the second paragraph to become an immediate following sibling of the first paragraph
            while (true)
            {
                TextElement previousBlock = secondParagraphOrBlockUIContainer.ElementStart.GetAdjacentElement(LogicalDirection.Backward) as TextElement;
                // Note: We cannot use Block.NextSibling property, because the structure is invalid during this process

                Invariant.Assert(previousBlock != null);

                if (previousBlock is Paragraph || previousBlock is BlockUIContainer)
                {
                    break;
                }

                Invariant.Assert(TextSchema.AllowsParagraphMerging(previousBlock.GetType()));
                previousBlock.Reposition(previousBlock.ContentStart, secondParagraphOrBlockUIContainer.ElementEnd);
            }

            // Now that paragraphs are next to each other merge them.

            // If one of paragraphs is empty we will apply special logic - to preserve a formatting from a non-empty one
            if (secondParagraphOrBlockUIContainer.TextRange.IsEmpty)
            {
                secondParagraphOrBlockUIContainer.RepositionWithContent(null);
//.........这里部分代码省略.........