I want to set WebView to WebViewBrush in order to add inside rectangle and print rectangle. I want to do everything on the backend side, I don't want to use XAML code.
I do this because I get blurry/fuzzy text when I get a print preview. So people say the way to solve this is to create WebViewBrush and then create a rectangle to print that
First I create canvas and brush as:
private Windows.UI.Xaml.Controls.WebView ViewToPrint = new Windows.UI.Xaml.Controls.WebView();
private Windows.UI.Xaml.Controls.WebViewBrush wvBrush = new Windows.UI.Xaml.Controls.WebViewBrush();
private Windows.UI.Xaml.Shapes.Rectangle rectangle = new Windows.UI.Xaml.Shapes.Rectangle();
Then in method I assign WebView to WebViewBrush and add it to a rectangle,
public async void Print(Xamarin.Forms.WebView viewToPrint, string html)
{
ViewToPrint.NavigateToString(html);
wvBrush.SetSource(ViewToPrint);
wvBrush.Redraw();
rectangle.Fill = wvBrush;
rectangle.Width = 200;
rectangle.Height = 200;
}
Then inside print preview method I want to see that rectangle preview as:
private void PrintDoc_GetPreviewPage(object sender, GetPreviewPageEventArgs e)
{
printDoc.SetPreviewPage(e.PageNumber, rectangle);
}
But my rectangle is blank, I don't see anything inside it. What I'm doing wrong
Reproduce the issue:
Xamarin shared project class:
private readonly IPrintUWPService _printUWPService = DependencyService.Get<IPrintUWPService>();
public void Printhtml()
{
var meta = "<meta name='viewport' content='width=device-width, initial-scale=5.0, maximum-scale=5.0, minimum-scale=1.0'>";
var style = "<style>svg{height:140px; width:140px;} p{font-size:20px;} </style>";
var _htmlSource = @$"
<!DOCTYPE html>
<html>
<head>
{meta}
{style}
</head>
<body>
<table border = '1px solid'; style='border-collapse:collapse;'>
<tbody>
<tr>
<td>qr</td>
<td>
<p><b>Heat Number:number</b></p>
<p><b> Cylinder Type Name: cylindername</b></p>
<p><b> Color: colorname</b></p>
</td>
</tr>
</tbody>
</table>
</body>
</html>
";
Print(_htmlSource);
}
public void Print(string _htmlSource)
{
_printUWPService.Print( _htmlSource);
}
Interface in shared project:
public interface IPrintUWPService
{
void Print(string html);
}
UWP project service:
public class PrintUWPService : IPrintUWPService
{
PrintManager printmgr = PrintManager.GetForCurrentView();
PrintDocument PrintDoc;
PrintDocument printDoc;
PrintTask Task;
private Windows.UI.Xaml.Controls.WebView ViewToPrint = new Windows.UI.Xaml.Controls.WebView();
private DeviceInformationCollection deviceCollection;
private Windows.UI.Xaml.Shapes.Rectangle rectangle = new Windows.UI.Xaml.Shapes.Rectangle();
public PrintUWPService()
{
printmgr.PrintTaskRequested += Printmgr_PrintTaskRequested;
}
public async void Print(Xamarin.Forms.WebView viewToPrint, string html)
{
ViewToPrint.NavigateToString(html);
//MakePage();
if (PrintDoc != null)
{
printDoc.GetPreviewPage -= PrintDoc_GetPreviewPage;
printDoc.Paginate -= PrintDoc_Paginate;
printDoc.AddPages -= PrintDoc_AddPages;
}
printDoc = new PrintDocument();
try
{
printDoc.GetPreviewPage += PrintDoc_GetPreviewPage;
printDoc.Paginate += PrintDoc_Paginate;
printDoc.AddPages += PrintDoc_AddPages;
var showprint = PrintManager.ShowPrintUIAsync();
}
catch (Exception e)
{
Debug.WriteLine(e.ToString());
}
PrintDoc = null;
GC.Collect();
}
private void MakePage()
{
var brush = new WebViewBrush
{
Stretch = (Windows.UI.Xaml.Media.Stretch)Windows.UI.Xaml.Media.Stretch.Uniform
};
brush.SetSource(ViewToPrint);
brush.Redraw();
using (var waitHandle = new System.Threading.ManualResetEventSlim(initialState: false))
waitHandle.Wait(TimeSpan.FromMilliseconds(5000));
rectangle.Width = 200;
rectangle.Height = 200;
rectangle.Fill = brush;
brush.Stretch = (Windows.UI.Xaml.Media.Stretch)Windows.UI.Xaml.Media.Stretch.UniformToFill;
brush.AlignmentY = AlignmentY.Top;
rectangle.Name = "MyWebViewRectangle";
rectangle.Visibility = Windows.UI.Xaml.Visibility.Visible;
}
private void Printmgr_PrintTaskRequested(PrintManager sender, PrintTaskRequestedEventArgs args)
{
var deff = args.Request.GetDeferral();
Task = args.Request.CreatePrintTask($"Card Stock { DateTime.Now}", OnPrintTaskSourceRequested);
deff.Complete();
}
async void OnPrintTaskSourceRequested(PrintTaskSourceRequestedArgs args)
{
var def = args.GetDeferral();
await Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
{
args.SetSource(printDoc.DocumentSource);
});
def.Complete();
}
private void PrintDoc_AddPages(object sender, AddPagesEventArgs e)
{
printDoc.AddPage(rectangle);
printDoc.AddPagesComplete();
}
private async void PrintDoc_Paginate(object sender, PaginateEventArgs e)
{
PrintTaskOptions printingOptions = ((PrintTaskOptions)e.PrintTaskOptions);
deviceCollection = await DeviceInformation.FindAllAsync("System.Devices.InterfaceClassGuid:=\"{0ecef634-6ef0-472a-8085-5ad023ecbccd}\"");
var rolloPrinter = deviceCollection.Where(x => x.Name.Contains("Rollo")).SingleOrDefault();
// Get the page description to deterimine how big the page is
PrintPageDescription pageDescription = printingOptions.GetPageDescription(0);
PrintTaskOptions opt = Task.Options;
printDoc.SetPreviewPageCount(1, PreviewPageCountType.Final);
}
private void PrintDoc_GetPreviewPage(object sender, GetPreviewPageEventArgs e)
{
printDoc.SetPreviewPage(e.PageNumber, rectangle);
}
}
