I'm creating a control that allows the user to create a visual element that can be printed. The challenge is the user can change the size of visual but needs to know the actual size of the visual they are creating. In other words I have the size of the element in pixels but I need to know what the actual size of the element will be in inches.
For example if I create a button that is 96 pixels wide, I would expect it to be 1 inch long, yet the size of the button is different on different monitors with different resolutions.
Is this possible?
It is not possible in cases where you don't know the actual PPI of your monitor (such as with a projector), but here is an attempt at calculating it from a Rectangle of 96x96 device independent pixels:
var ppi = 220; //The PPI on my monitor.
var devicePixels = GetElementPixelSize(MyRectangle); //Convert WPF pixels to device pixels
var widthInInches = devicePixels.Width / ppi; //Convert pixels to inches based on the PPI.
Using this code (from How do I convert a WPF size to physical pixels?)
public Size GetElementPixelSize(UIElement element)
{
Matrix transformToDevice;
var source = PresentationSource.FromVisual(element);
if (source != null)
transformToDevice = source.CompositionTarget.TransformToDevice;
else
using (var source2 = new HwndSource(new HwndSourceParameters()))
transformToDevice = source2.CompositionTarget.TransformToDevice;
if (element.DesiredSize == new Size())
element.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity));
return (Size)transformToDevice.Transform((Vector)element.DesiredSize);
}
In my case, 96 translates to 144px. 144/220 is 0.65656565 inches.
To get the ppi, take a look at this question: acquire monitor physical dimension
It is not an easy task, and there is no guarantee that simply because it is rendered a certain size, it will also look that way on print. A printer also has a DPI and a paper size, after all.
You really should google on WPF, DPI and Scaling because the scaling system of WPF has some important characteristics. From the search you will find this site for a first read about the topic.
About your question is this possible? Yes it surely is! ;)
Related
I'm working on a "GS Wrapper" (using the 9.20 SDK) for use by an external application. There i scale down for example a A0 Sheet to A1, A2 and A3 and it works fine. (PDF to PS, then Print)
Problem: When i scale down any input format to A4, the printer cut off the borders of the content (these are technical drawings with a black border each 5mm from the sheet edge).
Is there an opportunity to scale down the A4 (to A4) again about 95% and center the image? (This should be result in a smaller base image, say the black borders are about ~10mm away from the sheet border afterwards)
I use the following parameter for scaling:
GhostArg[0] = "-dNOPAUSE";
GhostArg[1] = "-dBATCH";
GhostArg[2] = "-dSAFER";
GhostArg[3] = "-dNOPAUSE";
GhostArg[4] = "-g2480x3508";
GhostArg[5] = "-dPDFFitPage";
GhostArg[6] = "-r300x300";
GhostArg[7] = "-sDEVICE=ps2write";
GhostArg[8] = Output;
GhostArg[9] = Input;
Solution Update:
I managed to fix this problem by insert this three lines between Arg[8] and Arg[9]:
GhostArg[9] = "-c";
GhostArg[10] = "<< /BeginPage { 0.99 0.99 scale 10 10 translate } >> setpagedevice";
GhostArg[11] = "-f";
Thanks to KenS for the /BeginPage hint.
It sounds like your printer has a non-printable area. This is not uncommon, the paper handling needs to hold the paper while its being printed, and this can lead to some areas of the media not being printable.
If your content reaches to the edge of the media, its possible that the printer simple cannot print there, resulting in the content being cropped.
It is entirely possible to have ps2write drop the media content to a smaller size, but you can't have it (automatically) scale down and also shift the content location, because the content is fitted to the media size.
However, the FitPage mechanism doesn't look at the content, just the media size requests. So if the input requests A3 and the selected media is A4 (and fixed) then a scale factor is applied to scale the content to the required media size (and the media request for A3 is ignored).
So what you could do is leave the code you have as it is as present, but add a BeginPage or Install procedure which uses the scale operator to further reduce the size of marks on the page, and the translate operator to move the origin slightly so that the final content is centered.
Something like (example only, untested):
<<
/BeginPage {
0.95 0.95 scale
16 20 translate
}
>> setpagedevice
By the way, you do realise Ghostscript is licenced under the AGPL ?
Also, I'd very strongly recommend that you do not use the -g and -r switches, but instead simply use -dDEVICEWIDTHPOINTS and -dDEVICEHEIGHTPOINTS to alter the media size.
The -g switch works in pixels, but high level output devices (eg pdfwrite and ps2write) don't emit pixels, they write high level vector objects. However, due to differences in the PostScript and PDF graphics models, some elements do need to be rendered to images and enclosed in that fashion in the PostScript output. By setting the resolution to 300 you are fixing the resolution at which those elements (eg pages containing transparency) are rendered. I'd suggest that you don't do so, unless you are working in a very tightly controlled workflow and know the resolution of the final output.
By using the DEVICEHEIGHTPOINTS and DEVICEWIDTHPOINTS switches you can control the media size without reference to the resolution. Note that in PostScript (and PDF) 1 point = 1/72 inch.
I try to load an excel file and show in xpsdocument viewer by following code
XpsDocument xpsDocument = ef.ConvertToXpsDocument(SaveOptions.XpsDefault);
documentViewer.Tag = xpsDocument;
documentViewer.Document = xpsDocument.GetFixedDocumentSequence();
That works so far. The problem is that during the conversion the pagesize changes. It seems that a 8 by 11 inch pagesize is assumed and the document is streched. Excel document is designed for A4 papersize. That means the width grows and the last column moves to the next page.
How can I influence the paper size and border width for SaveOptions.XpsDefault??
The A4 format is 8.267" x 11.692" so it seems that the assumption is right. Nevertheless, you can change the paper size like the following:
ExcelWorksheet ws = ef.Worksheets.ActiveWorksheet;
ws.PrintOptions.PaperType = PaperType.A4;
However, regarding the content being moved to next page, this will require investigating your Excel file's content.
But in case you're interested you can explicitly specify that the content's width (and/or height) should fit on a single page, like the following:
ws.PrintOptions.FitWorksheetWidthToPages = 1;
Last regarding the borders, you can specify the width by using LineStyle.
I've got a WinForms application that works great on older systems, but I'm having trouble making it look good on 4k monitors. There are multiple issues, and a lot written on the subject, but this question is focused on one specific problem. I can set different controls to use the same font, but on high DPI systems, the controls will look a lot different. How can I fix this?
Obviously I can change the font size, move controls around, etc. But Windows is adding a mysterious factor into my font sizes. Without knowing what Windows is doing, it's hard for me to undo it!
On an older system my test window looks perfect:
On a high DPI system, some controls have a different font size than others:
I've tried several things, including manually setting the font on some controls rather than inheriting from the form. As you can see, changing the font did not fix the problem:
After searching the Internet I've tried several things to fix this including:
Changing the application between PROCESS_DPI_UNAWARE, PROCESS_SYSTEM_DPI_AWARE, and PROCESS_PER_MONITOR_DPI_AWARE
Explicitly changing the font rather than using the form's font.
Building on an old system vs building on a high DPI system.
Building on a monitor set to 96 DPI / 100% vs building on a monitor set to 192 DPI / 200% on the same computer.
Building the form in visual studio's designer vs building it in pure C# code.
.Net 4.0 vs. .Net 4.6.1
Visual Studio 2010 vs Visual Studio 2015
I only found one thing that fixed my problem. Unfortunately I had to do it on the target machine, not on the machine where I'm building this. So it's not a practical solution. See the second item under "steps to repeat" for more details.
Steps to repeat:
This happens with a lot of controls on a lot of forms. See the code sample below for a small, simple demo. That's how I got the screenshots, above.
I can make this problem appear or disappear with one system setting. If you change the main monitor to 96 DPI / 100% scaling, then reboot, you'll get the good result where all fonts are as requested. If you change the main monitor to a different DPI setting, then reboot, you'll see the bad results.
private void newFormButton_Click(object sender, EventArgs e)
{
Font copyOfFont = new Font(Font, FontStyle.Strikeout);
Form form = new Form();
form.Font = Font;
string sample = "Abc 123 :)";
int padding = 6;
Label label = new Label();
label.Text = sample;
label.Top = padding;
label.Left = padding;
label.Font = copyOfFont;
label.Parent = form;
Button button = new Button();
button.Text = sample;
button.Top = label.Bottom + padding;
button.Left = padding;
button.Width = label.Width + padding * 2;
button.Height = label.Height + padding * 2;
button.Parent = form;
TextBox textBox = new TextBox();
textBox.Text = sample;
textBox.Size = button.Size;
textBox.Top = button.Bottom + padding;
textBox.Left = padding;
textBox.Parent = form;
ListBox listBox = new ListBox();
listBox.Items.Add(sample);
listBox.Items.Add(sample);
listBox.Width = button.Width;
listBox.Height = button.Height * 2;
listBox.Top = textBox.Bottom + padding;
listBox.Left = padding;
listBox.Font = copyOfFont;
listBox.Parent = form;
form.Show();
}
This is crazy but it works.
Everything I've seen on the internet about DPI Virtualization says that Windows will automatically set a process to PROCESS_DPI_UNAWARE by default. So unless you explicitly pick one of the other two settings, your application should look decent on a high resolution monitor. It might be a little fuzzy, but it shouldn't look as bad as the examples I've shown above.
Apparently that's not true. The default depends on the computer, and it depends on the day. My solution: Explicitly set the application to use PROCESS_DPI_UNAWARE. I've included a code sample below.
Note that you should be able to take care of this using the manifest. Some sources say that's the preferred way, rather than using C# code. We've had mixed results with that. The C# code option seems more reliable.
[DllImport("shcore.dll")]
static extern int SetProcessDpiAwareness(_Process_DPI_Awareness value);
enum _Process_DPI_Awareness
{
Process_DPI_Unaware = 0,
Process_System_DPI_Aware = 1,
Process_Per_Monitor_DPI_Aware = 2
}
public MainForm()
{
//int result = SetProcessDpiAwareness(_Process_DPI_Awareness.Process_System_DPI_Aware);
//int result = SetProcessDpiAwareness(_Process_DPI_Awareness.Process_Per_Monitor_DPI_Aware);
int result = SetProcessDpiAwareness(_Process_DPI_Awareness.Process_DPI_Unaware);
System.Diagnostics.Debug.Assert(result == 0);
This works on a number of different developer machines. We're about to start sending the fix out to beta testers.
Summary
The O/S provides a compatibility mode for old programs running on high DPI systems.
WinForms and the O/S provide tools for manually changing the sizes of your controls depending on the DPI of the system
or the current monitor.
Both #1 and #2 are both seriously buggy!
The details var a lot from one computer to the next.
Fixing #2 would be the more
powerful option, but as far as I can tell it would be impossible to
fix that.
Instead I fixed #1. That works reasonably well.
Our tool allows export to PNG, which works very nicely.
Now, I would like to add export to some vector format. I tried XPS, but the results are not satisfying at all.
Take a look at a comparison http://www.jakubmaly.cz/xps-vs-png.png.
The picture on the left comes from an XPS export, the picture on the right from PNG export, the XPS picture is visibly blurred when opened in XPS Viewer and zoomed 100%.
Are there any settings that I am missing or why is it so?
Thanks,
Jakub.
A sample xps output can be found here: http://www.jakubmaly.cz/files/a.xps.
This is the code that does the XPS export:
if (!boundingRectangle.HasValue)
{
boundingRectangle = new Rect(0, 0, frameworkElement.ActualWidth, frameworkElement.ActualHeight);
}
// Save current canvas transorm
Transform transform = frameworkElement.LayoutTransform;
// Temporarily reset the layout transform before saving
frameworkElement.LayoutTransform = null;
// Get the size of the canvas
Size size = new Size(boundingRectangle.Value.Width, boundingRectangle.Value.Height);
// Measure and arrange elements
frameworkElement.Measure(size);
frameworkElement.Arrange(new Rect(size));
// Open new package
System.IO.Packaging.Package package = System.IO.Packaging.Package.Open(filename, FileMode.Create);
// Create new xps document based on the package opened
XpsDocument doc = new XpsDocument(package);
// Create an instance of XpsDocumentWriter for the document
XpsDocumentWriter writer = XpsDocument.CreateXpsDocumentWriter(doc);
// Write the canvas (as Visual) to the document
writer.Write(frameworkElement);
// Close document
doc.Close();
// Close package
package.Close();
// Restore previously saved layout
frameworkElement.LayoutTransform = transform;
Interesting (and annoying) issue - you may want to check out the lengthy answer from Jo0815 to Printing XpsDocument causes resampled images (96dpi?) - FixedDocument prints sharp, quoting a Microsoft support response - a couple of excerpts:
Some vector features from WPF cannot be emulated in our GDI code and
we resort to converting subsets of the scene to GDI bitmaps. These
bitmaps are the cause of the blurred zooming.
[...]
These bitmaps are the cause of the blurred zooming. The problem is
that the WPF is being rasterised to a bitmap at the -wrong resolution.
The print path is designed to rasterise unsupported features into a
bitmap, but it is supposed to do it at device resolution. Instead the
rasterisation is always being done at 96dpi. That's fine for a screen
but produces blurred output for a 600dpi printer. [emphasis mine]
Please note that the latter will apply for nowadays higher DPI screens as well of course, I've encountered blurring like this various times already - do you by chance use a high DPI monitor?
Now, apparently Microsoft is not entirely in control of the apparatus regarding this:
Additionally the problem only occurs when printing XPS and isn't a
problem when printing XAML directly. I'm pretty sure there is
documentation somewhere that says XPS will print at device resolution.
[...] It is something we
plan to improve in the next version of the product but not for Win 7.
The problem is that when printing XAML it will correctly render the
image at 600dpi, but when printing XPS it will still render the image
at 96dpi. Since XAML is converted to XPS before printing it seems
highly odd that one method of printing XPS produces different results
to another method of printing XPS. [emphasis mine]
[...]
There is no UI to configure the XPS Document Writer DPI. If you later
print a generated XPS document at a different DPI from the writers
internal default you may get poor results for bitmap content. With GDI
printers you can control the final DPI and your final desitination is
usally paper - no chance to reprint the document.
Conclusion
In conclusion, I'd still try to adjust PrintTicket.PageResolution Property within Néstor Sánchez' approach (+1), if your use case does allow this (though I remotely recall reading somewhere, that this doesn't have any effect as well); section Bitmap Resolution and Pixel Format in Using the XPS Rasterization Service confirms the issue he encountered with FixedDocument:
XPS rasterizer object for a fixed page must know the resolution at
which the page will be rendered. The XPSDrv filter specifies this
resolution, in dots per inch (DPI), as an input parameter [...] For example, if a display device has a resolution
of 600 DPI, and a fixed page describes a standard letter-size page, a
bitmap image of the entire page has the following dimensions [...]
Workaround
As a potential workaround you might want to explore alexandrud's solution for the related question How to convert a XPS file to an image in high quality (rather than blurry low resolution)?, which recommends using xps2img, a XPS (XML Paper Specification) document to set of images conversion utility. In particular it Allows to specify images size or DPI, which might help depending on the print path solution applied in turn.
Good luck!
I've had a similar problem. My image was very blurry when passed to XPS intermediated thru a FixedDocument.
The solution was to write the image directly to the XPS...
/// <summary>
/// Saves the supplied visual Source, within the specified Bounds, as XPS in the specified File-Name.
/// Returns error message or null when succeeded.
/// </summary>
public static string SaveVisualAsXPS(Visual Source, Size Bounds, string FileName)
{
string ErrorMessage = null;
try
{
using (var Container = Package.Open(FileName, FileMode.Create))
{
using (var TargetDocument = new XpsDocument(Container, CompressionOption.Maximum))
{
var Writer = XpsDocument.CreateXpsDocumentWriter(TargetDocument);
var Ticket = GetPrintTicketFromPrinter();
if (Ticket == null)
return "No printer is defined.";
Ticket.PageMediaSize = new PageMediaSize(Bounds.Width, Bounds.Height);
var SourceVisual = Source;
Writer.Write(SourceVisual, Ticket);
}
}
}
catch (Exception Problem)
{
ErrorMessage = "Cannot export document to XPS.\nProblem: " + Problem.Message;
}
return ErrorMessage;
}
Giving a print-ticket with the exact width and height avoids scaling (that was I wanted in my case).
Get the function from the example in:
http://msdn.microsoft.com/en-us/library/system.printing.printticket.aspx
What's the best way to convert a WPF (resolution-independent) width and height to physical screen pixels?
I'm showing WPF content in a WinForms Form (via ElementHost) and trying to work out some sizing logic. I've got it working fine when the OS is running at the default 96 dpi. But it won't work when the OS is set to 120 dpi or some other resolution, because then a WPF element that reports its Width as 96 will actually be 120 pixels wide as far as WinForms is concerned.
I couldn't find any "pixels per inch" settings on System.Windows.SystemParameters. I'm sure I could use the WinForms equivalent (System.Windows.Forms.SystemInformation), but is there a better way to do this (read: a way using WPF APIs, rather than using WinForms APIs and manually doing the math)? What's the "best way" to convert WPF "pixels" to real screen pixels?
EDIT: I'm also looking to do this before the WPF control is shown on the screen. It looks like Visual.PointToScreen could be made to give me the right answer, but I can't use it, because the control isn't parented yet and I get InvalidOperationException "This Visual is not connected to a PresentationSource".
Transforming a known size to device pixels
If your visual element is already attached to a PresentationSource (for example, it is part of a window that is visible on screen), the transform is found this way:
var source = PresentationSource.FromVisual(element);
Matrix transformToDevice = source.CompositionTarget.TransformToDevice;
If not, use HwndSource to create a temporary hWnd:
Matrix transformToDevice;
using(var source = new HwndSource(new HwndSourceParameters()))
transformToDevice = source.CompositionTarget.TransformToDevice;
Note that this is less efficient than constructing using a hWnd of IntPtr.Zero but I consider it more reliable because the hWnd created by HwndSource will be attached to the same display device as an actual newly-created Window would. That way, if different display devices have different DPIs you are sure to get the right DPI value.
Once you have the transform, you can convert any size from a WPF size to a pixel size:
var pixelSize = (Size)transformToDevice.Transform((Vector)wpfSize);
Converting the pixel size to integers
If you want to convert the pixel size to integers, you can simply do:
int pixelWidth = (int)pixelSize.Width;
int pixelHeight = (int)pixelSize.Height;
but a more robust solution would be the one used by ElementHost:
int pixelWidth = (int)Math.Max(int.MinValue, Math.Min(int.MaxValue, pixelSize.Width));
int pixelHeight = (int)Math.Max(int.MinValue, Math.Min(int.MaxValue, pixelSize.Height));
Getting the desired size of a UIElement
To get the desired size of a UIElement you need to make sure it is measured. In some circumstances it will already be measured, either because:
You measured it already
You measured one of its ancestors, or
It is part of a PresentationSource (eg it is in a visible Window) and you are executing below DispatcherPriority.Render so you know measurement has already happened automatically.
If your visual element has not been measured yet, you should call Measure on the control or one of its ancestors as appropriate, passing in the available size (or new Size(double.PositivieInfinity, double.PositiveInfinity) if you want to size to content:
element.Measure(availableSize);
Once the measuring is done, all that is necessary is to use the matrix to transform the DesiredSize:
var pixelSize = (Size)transformToDevice.Transform((Vector)element.DesiredSize);
Putting it all together
Here is a simple method that shows how to get the pixel size of an element:
public Size GetElementPixelSize(UIElement element)
{
Matrix transformToDevice;
var source = PresentationSource.FromVisual(element);
if(source!=null)
transformToDevice = source.CompositionTarget.TransformToDevice;
else
using(var source = new HwndSource(new HwndSourceParameters()))
transformToDevice = source.CompositionTarget.TransformToDevice;
if(element.DesiredSize == new Size())
element.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity));
return (Size)transformToDevice.Transform((Vector)element.DesiredSize);
}
Note that in this code I call Measure only if no DesiredSize is present. This provides a convenient method to do everything but has several deficiencies:
It may be that the element's parent would have passed in a smaller availableSize
It is inefficient if the actual DesiredSize is zero (it is remeasured repeatedly)
It may mask bugs in a way that causes the application to fail due to unexpected timing (eg. the code being called at or above DispatchPriority.Render)
Because of these reasons, I would be inclined to omit the Measure call in GetElementPixelSize and just let the client do it.
Simple proportion between Screen.WorkingArea and SystemParameters.WorkArea:
private double PointsToPixels (double wpfPoints, LengthDirection direction)
{
if (direction == LengthDirection.Horizontal)
{
return wpfPoints * Screen.PrimaryScreen.WorkingArea.Width / SystemParameters.WorkArea.Width;
}
else
{
return wpfPoints * Screen.PrimaryScreen.WorkingArea.Height / SystemParameters.WorkArea.Height;
}
}
private double PixelsToPoints(int pixels, LengthDirection direction)
{
if (direction == LengthDirection.Horizontal)
{
return pixels * SystemParameters.WorkArea.Width / Screen.PrimaryScreen.WorkingArea.Width;
}
else
{
return pixels * SystemParameters.WorkArea.Height / Screen.PrimaryScreen.WorkingArea.Height;
}
}
public enum LengthDirection
{
Vertical, // |
Horizontal // ——
}
This works fine with multiple monitors as well.
I found a way to do it, but I don't like it much:
using (var graphics = Graphics.FromHwnd(IntPtr.Zero))
{
var pixelWidth = (int) (element.DesiredSize.Width * graphics.DpiX / 96.0);
var pixelHeight = (int) (element.DesiredSize.Height * graphics.DpiY / 96.0);
// ...
}
I don't like it because (a) it requires a reference to System.Drawing, rather than using WPF APIs; and (b) I have to do the math myself, which means I'm duplicating WPF's implementation details. In .NET 3.5, I have to truncate the result of the calculation to match what ElementHost does with AutoSize=true, but I don't know whether this will still be accurate in future versions of .NET.
This does seem to work, so I'm posting it in case it helps others. But if anyone has a better answer, please, post away.
Just did a quick lookup in the ObjectBrowser and found something quite interesting, you might want to check it out.
System.Windows.Form.AutoScaleMode, it has a property called DPI. Here's the docs, it might be what you are looking for :
public const
System.Windows.Forms.AutoScaleMode Dpi
= 2
Member of System.Windows.Forms.AutoScaleMode
Summary: Controls scale relative to
the display resolution. Common
resolutions are 96 and 120 DPI.
Apply that to your form, it should do the trick.
{enjoy}