如果我有一个var flow = new FlowDocument()，并且向其BlockCollection添加了几个块：
if (m_Blocks == null || m_Blocks.Count <= 0)
return flow;
flow.Blocks.AddRange(m_Blocks.ToList());
var paginatorSource = flow as IDocumentPaginatorSource;
paginatorSource.DocumentPaginator.ComputePageCount();
var pageCount = paginatorSource.DocumentPaginator.PageCount;
我能够确定此文档包含多少页。
如果页数大于1，我该如何找出文档的哪些块无法放入首页？我在Block类上找不到任何可以帮助我确定这一点的东西。但是由于分页者可以ComputePageCount()，所以我认为这是可能的。
对于要完成的工作，我采取了蛮力的方法。基本上，我需要在每页顶部重复一个Paragraph。我想这不是最高效的方法，但是它完成了工作：
protected FlowDocument RenderBody()
{
var flow = new FlowDocument
{
PageWidth = PaperSizeDPI.Width,PageHeight = PaperSizeDPI.Height,ColumnGap = 0,ColumnWidth = PaperSizeDPI.Width,PagePadding = new Thickness(MarginDPI.Left,MarginDPI.Top + HeaderHeightDPI,MarginDPI.Right,MarginDPI.Bottom + FooterHeightDPI)
};
if (m_Blocks == null || m_Blocks.Count <= 0)
return flow;
// Get page count before deciding to deal with repeat blocks.
// Adding blocks to the FlowDocument is required before invoking
// `DocumentPaginator.ComputePageCount()`.
flow.Blocks.AddRange(m_Blocks.ToList());
int GetPageCount()
{
var paginatorSource = (IDocumentPaginatorSource) flow;
paginatorSource.DocumentPaginator.ComputePageCount();
return paginatorSource.DocumentPaginator.PageCount;
}
// If there is only one page,no roll-over of headers necessary
if (GetPageCount() <= 1) return flow;
// If we don't have a header to repeat,we assume the report is correct already
if (PrintTemplateConverter.BuildRepeatableHeader == null) return flow;
// Build the FlowDocument,one block at a time,checking if the page count
// changes so that we can inject a repeatable header
flow.Blocks.Clear();
var pageCount = 1;
var blocks = m_Blocks.ToList();
for (var blockIndex = 0; blockIndex < blocks.Count; blockIndex++)
{
flow.Blocks.Add(blocks[blockIndex]);
if (GetPageCount() <= pageCount) continue;
// If this block moved us to a new page,inject repeatable header in its spot.
// `flow.Blocks.AddRange(...)` ignores duplicate blocks (by reference).
// This is why I go through the "pain" of making a whole new Header block
// instance.
var blocksSoFar = flow.Blocks.ToList();
flow.Blocks.Clear();
blocksSoFar.Insert(blockIndex,PrintTemplateConverter.BuildRepeatableHeader());
flow.Blocks.AddRange(blocksSoFar);
pageCount = GetPageCount();
}
return flow;
}
我希望这对以后的人有帮助！