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;
}
