摘自:http://www.cnblogs.com/jiajiayuan/archive/2012/04/13/2444246.html
Silverlight中的打印只有一个类,那就是PrintDocment这个对象来实现。
下面我用两种方法来实现Silverlight的打印:
第一种:
private void btnPrint_Click(object sender, RoutedEventArgs e){PrintDocument document = new PrintDocument();// tell the API what to printdocument.PrintPage += (s, args) =>{args.PageVisual = GPrint;};// call the Print() with a proper name which will be visible in the Print Queuedocument.Print("Silverlight Print Application Demo");}
第二种:
实现方式也很简单,其实只需两个步骤即可完成,即绑定PrintDocument的PrintPage事件和调用Print方法。
PrintDocument document = new PrintDocument(); document.PrintPage += documentImage_PrintPage; document.Print("Image Document");
这个就完成了一个打印,其中PrintPage事件是最为重要的,因为整个打印的工作都是在这个事件中完成的,另外该事件的参数 PrintPageEventArgs构成了整个打印过程中的属性的设置;Print方法需要传递一个参数,参数为打印的文件的名称,在调用该方法的时候 开始触发一系列的打印事件。
PrintPageEventArgs类型的属性:
PrintableArea:获取一个Size类型的值,表示打印的范围,分别表示Height和Width,如果打印的部分超出了区域,则被截取。
PageMargins:获取打印页的Margin值。
PageVisual:设置要打印的对象,可以是一个TextBlock、Image,也可以是一个复杂的元素(Grid或者Canvas)。
HasMorePages:一个bool值,标识是否多页。
一个简单的例子:
private void btnPrintImage_Click(object sender, RoutedEventArgs e){PrintDocument document = new PrintDocument();document.PrintPage += new EventHandler<PrintPageEventArgs>(document_PrintPage);document.Print("Print Image");}void document_PrintPage(object sender, PrintPageEventArgs e){Image imagePrint = new Image();imagePrint.Source = img.Source;imagePrint.Height = e.PrintableArea.Height;imagePrint.Width = e.PrintableArea.Width;e.PageVisual = imagePrint;e.HasMorePages = false;}
分页打印的例子:
//当前打印的行的索引,用于遍历ListBox.Itemsprivate int listPrintIndex;private void btnPrintList_Click(object sender, RoutedEventArgs e){//初始值为0listPrintIndex = 0;PrintDocument document = new PrintDocument();document.PrintPage += new EventHandler<PrintPageEventArgs>(document_PrintPage);document.Print("Print List");}//设置每一项之间的间距private int extraMargin = 50;void document_PrintPage(object sender, PrintPageEventArgs e){//定义一个打印的元素Canvas printSurface = new Canvas();e.PageVisual = printSurface;//得到最顶端位置double topPosition = e.PageMargins.Top + extraMargin;//遍历当前的ListBox.Itemswhile (listPrintIndex<lstPrint.Items.Count){//实例化TextBlock用来存放ListItem的值TextBlock txt = new TextBlock();txt.FontSize = 30;//得到ListBox每一项的值txt.Text = lstPrint.Items[listPrintIndex].ToString();double measuredHeight = txt.ActualHeight;//如果打印的当前行高度不合适的话,则进行分页if (measuredHeight>(e.PrintableArea.Height- topPosition- extraMargin)){e.HasMorePages = true;return ;}//设置TextBlock在Canvas中的位置txt.SetValue(Canvas.TopProperty, topPosition);txt.SetValue(Canvas.LeftProperty, e.PageMargins.Left + extraMargin);//将TextBlock添加到打印的元素中去printSurface.Children.Add(txt);listPrintIndex++;//追加高度topPosition = topPosition + measuredHeight;}e.HasMorePages = false;}
有时我们会发现打印的图片并不完整,这样就需要一个类:
public static class Extensions{public static void Print(this FrameworkElement element,string Document, HorizontalAlignment HorizontalAlignment,VerticalAlignment VerticalAlignment, Thickness PageMargin,bool PrintLandscape, bool ShrinkToFit, Action OnPrintComplete){Print(new List<FrameworkElement>() { element }, Document,HorizontalAlignment, VerticalAlignment, PageMargin,PrintLandscape, ShrinkToFit, OnPrintComplete);}public static void Print<T>(this List<T> elements,string Document, HorizontalAlignment HorizontalAlignment,VerticalAlignment VerticalAlignment, Thickness PageMargin,bool PrintLandscape, bool ShrinkToFit, Action OnPrintComplete){PrintDocument printDocument = new PrintDocument();PageMargin = PageMargin == null ? new Thickness(10) : PageMargin;Document = (string.IsNullOrEmpty(Document)) ? "Print Document" : Document;int currentItemIndex = 0;printDocument.PrintPage += (s, e) =>{if (!typeof(FrameworkElement).IsAssignableFrom(elements[currentItemIndex].GetType())){throw new Exception("Element must be an " +"object inheriting from FrameworkElement");}FrameworkElement element = elements[currentItemIndex] as FrameworkElement;if (element.Parent == null || element.ActualWidth == double.NaN ||element.ActualHeight == double.NaN){throw new Exception("Element must be rendered, " +"and must have a parent in order to print.");}TransformGroup transformGroup = new TransformGroup();//First move to middle of page... 首先移动到页面的中间transformGroup.Children.Add(new TranslateTransform() //TranslateTransform偏移动画{X = (e.PrintableArea.Width - element.ActualWidth) / 2,Y = (e.PrintableArea.Height - element.ActualHeight) / 8});double scale = 1;if (PrintLandscape) //如果打印空白 需要旋转{//Then, rotate around the center 然后旋转到中心transformGroup.Children.Add(new RotateTransform(){Angle = 90,CenterX = e.PrintableArea.Width / 2,CenterY = e.PrintableArea.Height / 2});if (ShrinkToFit) //如果自适应大小{if ((element.ActualWidth + PageMargin.Left +PageMargin.Right) > e.PrintableArea.Height) //如果宽度大于纸张的高度{//Math.Round 方法 将值舍入到最接近的整数或指定的小数位数。 scale = Math.Round(e.PrintableArea.Height /(element.ActualWidth + PageMargin.Left + PageMargin.Right), 2);}if ((element.ActualHeight + PageMargin.Top + PageMargin.Bottom) > e.PrintableArea.Width) //如果高度大于纸张的宽度{double scale2 = Math.Round(e.PrintableArea.Width /(element.ActualHeight + PageMargin.Top + PageMargin.Bottom), 2);scale = (scale2 < scale) ? scale2 : scale;}}}else if (ShrinkToFit) //如果不打印空白并自适应大小 不需要旋转{//Scale down to fit the page + marginif ((element.ActualWidth + PageMargin.Left + PageMargin.Right) > e.PrintableArea.Width) //如果宽度大于纸张的宽度{scale = Math.Round(e.PrintableArea.Width /(element.ActualWidth + PageMargin.Left + PageMargin.Right), 2);}if ((element.ActualHeight + PageMargin.Top + PageMargin.Bottom) > e.PrintableArea.Height) //如果高度大于纸张的高度{double scale2 = Math.Round(e.PrintableArea.Height /(element.ActualHeight + PageMargin.Top + PageMargin.Bottom), 2);scale = (scale2 < scale) ? scale2 : scale;}}//Scale down to fit the page + marginif (scale != 1){transformGroup.Children.Add(new ScaleTransform() //ScaleTransform缩放动画{ScaleX = scale,ScaleY = scale,CenterX = e.PrintableArea.Width / 2,CenterY = e.PrintableArea.Height / 2});}if (VerticalAlignment == VerticalAlignment.Top){//Now move to Topif (PrintLandscape){transformGroup.Children.Add(new TranslateTransform(){X = 0,Y = PageMargin.Top - (e.PrintableArea.Height -(element.ActualWidth * scale)) / 2});}else{transformGroup.Children.Add(new TranslateTransform(){X = 0,Y = PageMargin.Top - (e.PrintableArea.Height -(element.ActualHeight * scale)) / 2});}}else if (VerticalAlignment == VerticalAlignment.Bottom){//Now move to Bottomif (PrintLandscape){transformGroup.Children.Add(new TranslateTransform(){X = 0,Y = ((e.PrintableArea.Height -(element.ActualWidth * scale)) / 2) - PageMargin.Bottom});}else{transformGroup.Children.Add(new TranslateTransform(){X = 0,Y = ((e.PrintableArea.Height -(element.ActualHeight * scale)) / 2) - PageMargin.Bottom});}}if (HorizontalAlignment == HorizontalAlignment.Left){//Now move to Leftif (PrintLandscape){transformGroup.Children.Add(new TranslateTransform(){X = PageMargin.Left - (e.PrintableArea.Width -(element.ActualHeight * scale)) / 2,Y = 0});}else{transformGroup.Children.Add(new TranslateTransform(){X = PageMargin.Left - (e.PrintableArea.Width -(element.ActualWidth * scale)) / 2,Y = 0});}}else if (HorizontalAlignment == HorizontalAlignment.Right){//Now move to Rightif (PrintLandscape){transformGroup.Children.Add(new TranslateTransform(){X = ((e.PrintableArea.Width -(element.ActualHeight * scale)) / 2) - PageMargin.Right,Y = 0});}else{transformGroup.Children.Add(new TranslateTransform(){X = ((e.PrintableArea.Width -(element.ActualWidth * scale)) / 2) - PageMargin.Right,Y = 0});}}e.PageVisual = element;e.PageVisual.RenderTransform = transformGroup;//Increment to next item,currentItemIndex++;//If the currentItemIndex is less than the number of elements, keep printinge.HasMorePages = currentItemIndex < elements.Count;};printDocument.EndPrint += delegate(object sender, EndPrintEventArgs e){foreach (var item in elements){FrameworkElement element = item as FrameworkElement;//Reset everything...TransformGroup transformGroup = new TransformGroup();transformGroup.Children.Add(new ScaleTransform() { ScaleX = 1, ScaleY = 1 }); //缩放动画transformGroup.Children.Add(new RotateTransform() { Angle = 0 }); //旋转动画transformGroup.Children.Add(new TranslateTransform() { X = 0, Y = 0 }); //偏移动画element.RenderTransform = transformGroup;}//Callback to completeif (OnPrintComplete != null){OnPrintComplete();}};printDocument.Print(Document);}}
调用这个类:
private void btnPrint_Click(object sender, RoutedEventArgs e){Extensions.Print(GPrint, "MyPrint",HorizontalAlignment.Center, VerticalAlignment.Top,new Thickness(10, 0, 10, 0), true, true, null);}
这样就能完整的打印了,不过打印出来的效果可能是横向的。