wpf打印控件 实现分页打印控件功能

因为 要实现打印 wpf  listbox控件  数据特别多 要打印在 几张纸上    找了几天 都没有找到相关的例子

现在 解决了 在这里和大家分享一下

public void print(FrameworkElement ViewContainer)

{

FrameworkElement objectToPrint = ViewContainer as FrameworkElement;

PrintDialog printDialog = new PrintDialog();

printDialog.PrintTicket.PageOrientation = PageOrientation.Landscape;

if ((bool)printDialog.ShowDialog().GetValueOrDefault())

{

Mouse.OverrideCursor = Cursors.Wait;

PrintCapabilities capabilities =

printDialog.PrintQueue.GetPrintCapabilities(printDialog.PrintTicket);

double dpiScale = 300.0 / 96.0;

FixedDocument document = new FixedDocument();

try                 {

objectToPrint.Width = capabilities.PageImageableArea.ExtentWidth;

objectToPrint.UpdateLayout();

objectToPrint.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity));

Size size = new Size(capabilities.PageImageableArea.ExtentWidth,

objectToPrint.DesiredSize.Height);

objectToPrint.Measure(size);

size = new Size(capabilities.PageImageableArea.ExtentWidth,

objectToPrint.DesiredSize.Height);

objectToPrint.Measure(size);

objectToPrint.Arrange(new Rect(size));

// Convert the UI control into a bitmap at 300 dpi

double dpiX = 300;

double dpiY = 300;

RenderTargetBitmap bmp = new RenderTargetBitmap(Convert.ToInt32(

capabilities.PageImageableArea.ExtentWidth * dpiScale),

Convert.ToInt32(objectToPrint.ActualHeight * dpiScale),

dpiX, dpiY, PixelFormats.Pbgra32);

bmp.Render(objectToPrint);

// Convert the RenderTargetBitmap into a bitmap we can more readily use

PngBitmapEncoder png = new PngBitmapEncoder();

png.Frames.Add(BitmapFrame.Create(bmp));

System.Drawing.Bitmap bmp2;

using (MemoryStream memoryStream = new MemoryStream())

{

png.Save(memoryStream);

bmp2 = new System.Drawing.Bitmap(memoryStream);

}

document.DocumentPaginator.PageSize =

new Size(printDialog.PrintableAreaWidth, printDialog.PrintableAreaHeight);

// break the bitmap down into pages

int pageBreak = 0;

int previousPageBreak = 0;

int pageHeight =

Convert.ToInt32(capabilities.PageImageableArea.ExtentHeight * dpiScale);

while (pageBreak < bmp2.Height - pageHeight)

{

pageBreak += pageHeight;  // Where we thing the end of the page should be

// Keep moving up a row until we find a good place to break the page

while (!IsRowGoodBreakingPoint(bmp2, pageBreak))                             pageBreak--;

PageContent pageContent = generatePageContent(bmp2, previousPageBreak,

pageBreak, document.DocumentPaginator.PageSize.Width,

document.DocumentPaginator.PageSize.Height, capabilities);                         document.Pages.Add(pageContent);                         previousPageBreak = pageBreak;                     }

// Last Page

PageContent lastPageContent = generatePageContent(bmp2, previousPageBreak,

bmp2.Height, document.DocumentPaginator.PageSize.Width,

document.DocumentPaginator.PageSize.Height, capabilities);

document.Pages.Add(lastPageContent);

}

finally

{

// Scale UI control back to the original so we don't effect what is on the screen

objectToPrint.Width = double.NaN;

objectToPrint.UpdateLayout();

objectToPrint.LayoutTransform = new ScaleTransform(1, 1);

Size size = new Size(capabilities.PageImageableArea.ExtentWidth,

capabilities.PageImageableArea.ExtentHeight);

objectToPrint.Measure(size);

objectToPrint.Arrange(new Rect(new Point(capabilities.PageImageableArea.OriginWidth,

capabilities.PageImageableArea.OriginHeight), size));

Mouse.OverrideCursor = null;

}

printDialog.PrintDocument(document.DocumentPaginator, "Print Document Name");

}         }

private PageContent generatePageContent(System.Drawing.Bitmap bmp, int top,          int bottom, double pageWidth, double PageHeight,          System.Printing.PrintCapabilities capabilities)         {

FixedPage printDocumentPage = new FixedPage();

printDocumentPage.Width = pageWidth;

printDocumentPage.Height = PageHeight;

int newImageHeight = bottom - top;

System.Drawing.Bitmap bmpPage = bmp.Clone(new System.Drawing.Rectangle(0, top,                    bmp.Width, newImageHeight), System.Drawing.Imaging.PixelFormat.Format32bppArgb);

// Create a new bitmap for the contents of this page

Image pageImage = new Image();

BitmapSource bmpSource =

System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(

bmpPage.GetHbitmap(),

IntPtr.Zero,

System.Windows.Int32Rect.Empty,

BitmapSizeOptions.FromWidthAndHeight(bmp.Width, newImageHeight));

pageImage.Source = bmpSource;

pageImage.VerticalAlignment = VerticalAlignment.Top;

// Place the bitmap on the page

printDocumentPage.Children.Add(pageImage);

PageContent pageContent = new PageContent();

((System.Windows.Markup.IAddChild)pageContent).AddChild(printDocumentPage);

FixedPage.SetLeft(pageImage, capabilities.PageImageableArea.OriginWidth);

FixedPage.SetTop(pageImage, capabilities.PageImageableArea.OriginHeight);

pageImage.Width = capabilities.PageImageableArea.ExtentWidth;

pageImage.Height = capabilities.PageImageableArea.ExtentHeight;

return pageContent;         }

private bool IsRowGoodBreakingPoint(System.Drawing.Bitmap bmp, int row)         {

double maxDeviationForEmptyLine = 1627500;

bool goodBreakingPoint = false;

if (rowPixelDeviation(bmp, row) < maxDeviationForEmptyLine)

goodBreakingPoint = true;

return goodBreakingPoint;

}         private double rowPixelDeviation(System.Drawing.Bitmap bmp, int row)

{

int count = 0;

double total = 0;

double totalVariance = 0;

double standardDeviation = 0;

System.Drawing.Imaging.BitmapData bmpData = bmp.LockBits(new System.Drawing.Rectangle(0, 0,

bmp.Width, bmp.Height), System.Drawing.Imaging.ImageLockMode.ReadOnly, bmp.PixelFormat);

int stride = bmpData.Stride;

IntPtr firstPixelInImage = bmpData.Scan0;

unsafe

{

byte* p = (byte*)(void*)firstPixelInImage;

p += stride * row;  // find starting pixel of the specified row

for (int column = 0; column < bmp.Width; column++)

{

count++;  //count the pixels

byte blue = p[0];

byte green = p[1];

byte red = p[3];

int pixelValue = System.Drawing.Color.FromArgb(0, red, green, blue).ToArgb();

total += pixelValue;

double average = total / count;

totalVariance += Math.Pow(pixelValue - average, 2);

standardDeviation = Math.Sqrt(totalVariance / count);

//go to next pixel

p += 3;

}

}

bmp.UnlockBits(bmpData);

return standardDeviation;

}