Develop Reference

How do I print clear text from a windows form?

I have successfully printed a windows form, but all the text is slightly blurry. I have concluded that this is a result of the resolution of the screen being much less than the resolution the printer uses. Is there a fundamental flaw in my approach or is there a way to reformat the text prior to printing so that it comes out crisp?
void PrintImage(object o, PrintPageEventArgs e)
{
int x = SystemInformation.WorkingArea.X;
int y = SystemInformation.WorkingArea.Y;
int width = panel1.Width;
int height = panel1.Height;
Rectangle bounds = new Rectangle(x, y, width, height);
Bitmap img = new Bitmap(width, height);
this.DrawToBitmap(img, bounds);
Point p = new Point(100, 100);
e.Graphics.DrawImage(img, p);
}
private void BtnPrint_Click(object sender, EventArgs e)
{
btnPrint.Visible = false;
btnCancel.Visible = false;
if(txtNotes.Text == "Notes:" || txtNotes.Text == "")
{
txtNotes.Visible = false;
}
PrintDocument pd = new PrintDocument();
pd.PrintPage += new PrintPageEventHandler(PrintImage);
pd.Print();
}

Is there a fundamental flaw in my approach [...] ?
Yes.
You take the size of panel1 to calculate the size of the image. Later, you let this draw to the image, but this is the form, not the panel.
What makes you think that SystemInformation.WorkingArea is related to the window you want to print?
You should take a bit more care of disposable objects.
[...] is there a way to reformat the text prior to printing so that it comes out crisp?
There's not a general way which would allow you to scale all other controls as well.
However, instead of blurry text, you can get crisp pixelated text by scaling the bitmap up by a certain factor using the NearestNeighbor mechanism.
Here's the difference in a PDF generated without scaling (left) and a factor of 3 scaling (right) at the same zoom level in Acrobat Reader (click to enlarge):
Here's the scaling code, also without fixing any disposable issues:
this.DrawToBitmap(img, bounds);
Point p = new Point(100, 100);
img = ResizeBitmap(img, 3);
e.Graphics.DrawImage(img, p);
}
private static Bitmap ResizeBitmap(Bitmap source, int factor)
{
Bitmap result = new Bitmap(source.Width*factor, source.Height*factor);
result.SetResolution(source.HorizontalResolution*factor, source.VerticalResolution*factor);
using (Graphics g = Graphics.FromImage(result))
{
g.InterpolationMode = InterpolationMode.NearestNeighbor;
g.DrawImage(source, 0, 0, source.Width*factor, source.Height*factor);
}
return result;
}

Create rectangle for the string that can be resized and center positioned

At first, I used drawString and GraphicsPath.AddString to draw outlined/solid text in the pictureBox. I can change it's font size, style and font-family but I realized that I won't be able to resized/stretch the text since the font size is proportionally distributed to the string. So the solution I was told was this:
I have been advised that in order to scale a Text (from a Draw String), I need to use a rectangle on which the text will depend on. In that way, I can resize the whole text (width, height, both). But I have no idea how to do it.
PS. If there are other ways, you can tell me. Thanks all.
Here's my TextDrawing Method:
public void DrawRects(Font f, string text, Graphics g, RectangleF rect)
{
List<RectangleF> list = new List<RectangleF>();
using (StringFormat format = new StringFormat())
{
int i;
format.Alignment = StringAlignment.Near;
format.LineAlignment = StringAlignment.Center;
format.Trimming = StringTrimming.None;
format.FormatFlags = StringFormatFlags.MeasureTrailingSpaces;
CharacterRange[] ranges = new CharacterRange[text.Length];
for (i = 0; i < text.Length; i++)
{
ranges[i] = new CharacterRange(i, 1);
}
format.SetMeasurableCharacterRanges(ranges);
Region[] regionArray = g.MeasureCharacterRanges(text, f, rect, format);
for (i = 0; i < regionArray.Length; i++)
{
list.Add(regionArray[i].GetBounds(g));
}
foreach (RectangleF r in list)
{
//g.SmoothingMode = SmoothingMode.AntiAlias;
//g.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAliasGridFit;
//g.InterpolationMode = InterpolationMode.High;
g.DrawRectangle(Pens.LightBlue, Rectangle.Round(r));
}
using (GraphicsPath path = new GraphicsPath())
{
path.AddString(text, f.FontFamily, Convert.ToInt32(f.Style), g.DpiY * rect.Height/72f, rect.Location, format);
RectangleF text_rectf = path.GetBounds();
PointF[] target_pts = {
new PointF(rect.Left, rect.Top),
new PointF(rect.Right, rect.Top),
new PointF(rect.Left, rect.Bottom)};
g.Transform = new Matrix(text_rectf, target_pts);
g.FillPath(Brushes.Red, path);
g.DrawPath(Pens.Red, path);
g.ResetTransform();
}
//g.SmoothingMode = SmoothingMode.AntiAlias;
//g.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAliasGridFit;
//g.InterpolationMode = InterpolationMode.High;
//g.DrawString(text, f, Brushes.Red, rect, format);
}
}
And my UI for your reference:
Result I need:
Edit: I changed the code on my text drawing, what I still can't do is to create different rectangles on each letters that is able o be resized using trackbar.

I had a go and I couldn't work out the rectangles relationship to the letters...
Never the less I propose a more elegant, time-tested and mathematically correct solution.
Alex Fr provided an excellent set of drawing tools in his DrawTools article and this project serves as a basis for Draw Tool Redux.
The original project by Alex Fr was based on a Microsoft C++ MFC sample project which developers may learn from DRAWCLI. The DrawTools C# program reproduces some of DRAWCLI functionality and uses some design decisions from this sample. These days the only way to see it is via WayBack machine link: https://web.archive.org/web/20120814082327/https://www.codeproject.com/Articles/8494/DrawTools
I'd recommend you swap drawing libraries and start off with a really well designed solution. The Draw Tool Redux has most of the functionality I see you need. With the exception of the Rotation Offset which I believe I've seen an example of in Rod Stephens book, here it is on WayBack Machine again: Interactively rotate images by an arbitrary angle in C#.

System.ComponentModel.Win32Exception: 'Error creating window handle.'

My problem is:
System.ComponentModel.Win32Exception: 'Error creating window handle'.
I know I can solve this problem with Dispose(), but when I use it in the program, I'm displaying another error:
System.ObjectDisposedException: 'Can not access a disposed object.
Object name: 'PictureBox'. '
I use the following code:
private void SetUpPuzzle_Click(int parts)
{
Panel P = new Panel
{
Size = new Size(200, 200),
Location = new Point(394, 62),
};
Controls.Add(P);
Control board = P;
int total = parts * parts;
var PB = new PictureBox[total];
var imgarray = new Image[total];
var img = User_Image.Image;
int W = img.Width / (int.Parse(Math.Sqrt(double.Parse(parts.ToString())).ToString()));
int H = img.Height / (int.Parse(Math.Sqrt(double.Parse(parts.ToString())).ToString()));
int size = 200 / (int.Parse(Math.Sqrt(double.Parse(parts.ToString())).ToString()));
for (int x = 0; x < parts; x++)
{
for (int y = 0; y < parts; y++)
{
var index = x * parts + y;
imgarray[index] = new Bitmap(W, H);
using (Graphics graphics = Graphics.FromImage(imgarray[index]))
graphics.DrawImage(img, new Rectangle(0, 0, W, H),
new Rectangle(x * W, y * H, W, H), GraphicsUnit.Pixel);
PB[index] = new PictureBox
{
Name = "P" + index,
Size = new Size(size, size),
Location = new Point(x * size, y * size),
Image = imgarray[index],
SizeMode = PictureBoxSizeMode.StretchImage
};
PB[index].MouseEnter += Images_M_E;
PB[index].MouseLeave += Images_M_L;
PB[index].MouseClick += Form_MouseClick;
*PB[index].Dispose();
*board.Controls.Add(PB[index]);
}
}
}
When I want to create 10,000 objects
This error is displayed.

My problem is:
System.ComponentModel.Win32Exception: 'Error creating window handle'.
Indeed. You are creating way too many controls for a Winforms application.
And disposing of them doesn't really help because you can't use a disposed object any longer..
To have this kind of large puzzle (10k pieces) you need to change from using PictureBoxes (or any other Controls) to display the puzzle pieces to a different approach. This has been suggested in the original question but then you only wanted to have 100 pieces, remember?
The most common approach is this: Keep a list of images (when they are <= 256x256 pixels do put them into an ImageList!) and draw them in the board's Paint event. This will get rid of all the overhead involved with PictureBoxes.
(Aside: One may think this will not be performant with all the DrawImage calls. But all those PictureBoxes also need to draw all the pixels on all their surfaces, so that is no issue. But they also have to carry the overhead of being (under the hood) fully functional windows (see the error message!), which is why the system can only have a limited number of them; always try to keep the number of controls < 1k!)
You will have to move the placement logic to the board's Paint event and will also have to change the event model..:
Instead of having each PictureBox respond to its own events you will have to find a way to do all the work in the board's events. This will have to be diffenrent, depending on the event.
Since we don't know which event you have and what they do and which data they need for their work, it is hard to give all the necessary details, so I'll just point out a few things..:
There will not be a Enter or Leave event you can use. Instead you need to detect entering an area of a piece by testing for it in the MouseMove event. If you keep a List<Rectangle> you can use Rectangle.Contains(e.Location) for this test.
You can detect a MouseClick but then will have to find out which area was clicked. If your Enter and Leave logic from the MouseMove is working you can use its result to know where the Click went.
Similar ideas can be used for all other events; some are simple, some need a little calculation but they will all be fast and pretty easy to implement..
To optimize performance try to make the image n the right size and use Format32bppPArgb as the pixel format, because it is faster to display.
Another option is to pull the pixel data right from the original image in the Paint event with the same calculations you use now to create them. (There is a DrawImage overlay that uses two Rectangles, one to determine the target and one for the source area..) This saves GDI handles, at least if you can't use an ImageList.
Always plan for growth! For a better implementation do create a Piece class. It should hold a Rectangle and an integer index into the ImageList's Images collection. It could also have a method Switch(Piece otherPiece) which would either switch the Rectangles or the indices.
Good luck :-)

I met this exception because endless loop creating new UI control and set its properties. After looped many times, this excption was thrown when change control visible property. I found both User Object and GDI Object (From Task Manager) are quite large.
I guess your issue is similar reason that system resources are exhaust by those UI controls.

I comment PB[index].Dispose(); and it's work.
private void SetUpPuzzle(int parts)
{
// Comment ***********
//Panel P = new Panel
//{
// Size = new Size(200, 200),
// Location = new Point(394, 62),
//};
//Controls.Add(P);
//Control board = P; ***********
int total = parts * parts;
var PB = new PictureBox[total];
var imgarray = new Image[total];
var img = User_Image.Image;
int W =Convert.ToInt32(img.Width / Math.Sqrt(parts));
int H = Convert.ToInt32(img.Height / Math.Sqrt(parts));
int size = Convert.ToInt32(200 / Math.Sqrt(parts));
for (int x = 0; x < parts; x++)
{
for (int y = 0; y < parts; y++)
{
var index = x * parts + y;
imgarray[index] = new Bitmap(W, H);
using (Graphics graphics = Graphics.FromImage(imgarray[index]))
graphics.DrawImage(img, new Rectangle(0, 0, W, H),
new Rectangle(x * W, y * H, W, H), GraphicsUnit.Pixel);
PB[index] = new PictureBox
{
Name = "P" + index,
Size = new Size(size, size),
Location = new Point(x * size, y * size),
Image = imgarray[index],
SizeMode = PictureBoxSizeMode.StretchImage
};
PB[index].MouseEnter += Form1_MouseEnter;
PB[index].MouseLeave += Form1_MouseLeave;
PB[index].MouseClick += Form1_MouseClick;
//Comment
//PB[index].Dispose(); < -----------------
// Add PB in Panel in form
panel1.Controls.Add(PB[index]);
}
}
// after add all refresh panel
panel1.Refresh();
}
private void Form1_MouseClick(object sender, MouseEventArgs e)
{
throw new NotImplementedException();
}
private void Form1_MouseLeave(object sender, EventArgs e)
{
throw new NotImplementedException();
}
private void Form1_MouseEnter(object sender, EventArgs e)
{
throw new NotImplementedException();
}
Then Call the SetUpPuzzle method in your button like :
private void button1_Click(object sender, EventArgs e)
{
SetUpPuzzle(10);
}

Error when drawing line in Graphics.DrawLine C# Visual Studio

private void Form1_Paint(object sender, PaintEventArgs e)
{
Graphics l = e.Graphics;
Pen p = new Pen(Color.Black, 1);
float angle = 0;
float len = 100;
PointF ori = new PointF(Width/2, 0);
PointF bob = new PointF(Width/2, len);
while(true)
{
bob.X = ori.X + len * (float)Math.Sin(angle);
bob.Y = ori.Y + len * (float)Math.Cos(angle);
angle += 0.001F;
l.DrawLine(p, ori.X, ori.Y, bob.X, bob.Y);
l.DrawEllipse(p, bob.X - 15, bob.Y, 30, 30);
if(angle == 360)
{
break;
}
l.Dispose();
}
}
The error line is l.DrawLine(p, ori.X, ori.Y, bob.X, bob.Y).
Error type: System.ArgumentException. Error Message: Parameter is not valid.
At first I thought the issue was with the floats but the DrawLine allows for such datatypes. It loops through once the error seems to occur when angle>0. Its magnitude doesn't seem to be the issue. Any help would be much appreciated. Thanks in advance. [UPDATE] Error seems to be with the l.Dispose

The problem is in the wrong Dispose call:
private void Form1_Paint(object sender, PaintEventArgs e)
{
Graphics l = e.Graphics;
// Pen is IDisposable, that's why why wrap it into "using": it's you who created it
using (Pen p = new Pen(Color.Black, 1)) {
float angle = 0;
float len = 100;
PointF ori = new PointF(Width/2, 0);
PointF bob = new PointF(Width/2, len);
while(true)
{
bob.X = ori.X + len * (float)Math.Sin(angle);
bob.Y = ori.Y + len * (float)Math.Cos(angle);
angle += 0.001F;
l.DrawLine(p, ori.X, ori.Y, bob.X, bob.Y);
l.DrawEllipse(p, bob.X - 15, bob.Y, 30, 30);
// angle is float, that's why == is not recommended:
// (you can well have 359.99999999999999) and thus == will never be true
if (angle >= 360)
break;
// l.Dispose(); // <- Wrong: it's not you who've created it
// (let system Dispose it)
}
}
}

As an enhancement to #Dmitry's answer, I can offer this advice:
As a general rule, you shouldn't call Dispose on an object that you do not control the lifetime of. You are getting an existing Graphics instance from the Paint event. The control that raised the Paint event is what created that Graphics object, so it is responsible for calling Dispose on it when it is done with it, not you.
When you call Dispose on an object that you don't control, you effectively "rip the rug out from under" that code. This is bad, because that code could be expecting the instance to still be alive so that it can perform other operations on it. By disposing it, you don't give it that chance.
You are doing the correct thing with your Pen instance, p, though. You create it during the using statement, so you are responsible for it. The Using handles that by automatically calling Dispose when execution leave the block.
If you had created the Graphicsinstance yourself, with something likeGraphics.FromImage`, then you would be responsible for cleaning it up.

PDFsharp DrawString Text Invisible for certain PDF

The system I am working on stamps PDF's with certain information. It does this by creating a lime green text box in the top right corner of the document. It then draws a certain string on top of the green space. This works for thousands of PDFs but for one the text is invisible even though the box is drawn. I can still select the text and copy it to something else, but it is invisible in the PDF.
Unfortunately, I cannot share the PDF but it is a PDF 1.4. What would cause this?
The code for stamping:
private static XGraphics drawString(XGraphics xgr, PdfPage page, string printString, int pageNumber = 0)
{
XFont font = new XFont("Verdana", 10, XFontStyle.BoldItalic);
var textSize = xgr.MeasureString(printString, font);
var width = textSize.Width;
var height = textSize.Height;
double xMin = 0;
double yMin = 0;
if (page.Rotate == 90)
{
xMin = page.Height - textSize.Width;
var state = xgr.Save();
xgr.DrawRectangle(XBrushes.LimeGreen, xMin, yMin, width, height);
xgr.Restore(state);
xgr.DrawString(printString, font, XBrushes.Black, new XRect(0, 0, page.Height, page.Width), topRight());
}
else
{
xMin = page.Width - textSize.Width;
var state = xgr.Save();
xgr.DrawRectangle(XBrushes.LimeGreen, xMin, yMin, width, height);
xgr.Restore(state);
xgr.DrawString(printString, font, XBrushes.Black, new XRect(0, 0, page.Width, page.Height), topRight());
}
return xgr;
}
private static XStringFormat topRight()
{
XStringFormat format = new XStringFormat();
format.Alignment = XStringAlignment.Far;
format.LineAlignment = XLineAlignment.Near;
return format;
}
I have tried using Dipose() on xgr and reinitialising it before each of its draw actions. I have tried saving and restoring the state of xgr between draw actions as seen in the code. I have tried various fonts and font sizes with no luck either.
Let me know what metadata about the PDF is relevant and I will share that.

Using PdfSharp 1.5 GDI, I have been having this issue as well. Some pdfs would be ok, others would have 1 or 2 pages that were ok, and then others would have no pages that were ok. Text could be selected, but text could not be seen. Changing the renderMode fixes the issue.
In PdfGraphicsState.cs, there is a condition to check if _realizedRenderingMode != renderMode. However, _realizedRenderingMode and renderMode is 0 by default, so it never enters codeblock, nor does it look like there is a method for changing the renderMode unless you change the font to italic, bold, strikeout, or underline:
int _realizedRenderingMode; // Reference: TABLE 5.2 Text state operators / Page 398
public void RealizeFont(XFont font, XBrush brush, int renderingMode)
{
const string format = Config.SignificantFigures3;
// So far rendering mode 0 (fill text) and 2 (fill, then stroke text) only.
RealizeBrush(brush, _renderer._colorMode, renderingMode, font.Size); // _renderer.page.document.Options.ColorMode);
// Realize rendering mode.
if (_realizedRenderingMode != renderingMode)
{
_renderer.AppendFormatInt("{0} Tr\n", renderingMode);
_realizedRenderingMode = renderingMode;
}
Removing the condition would suffice in fixing the issue, but the renderingMode seems to only be needed 1 time for the BT (Begin Text) in XGraphicsPdfRenderer.cs.
internal void BeginTextMode()
{
if (_streamMode != StreamMode.Text)
{
_streamMode = StreamMode.Text;
_content.Append("BT\n");
// Text matrix is empty after BT
_gfxState.RealizedTextPosition = new XPoint();
_gfxState.ItalicSimulationOn = false;
}
}
So, I ended up modifying XGraphics to include XGraphicsPdfRendererOptions and passing the variable to the various methods so it can be changed regardless of location:
private XGraphicsPdfRendererOptions _renderOptions { get; set; }
public XGraphicsPdfRendererOptions RenderOptions
{
get
{
if (_renderOptions == null)
{
_renderOptions = new XGraphicsPdfRendererOptions();
}
return _renderOptions;
}
set
{
_renderOptions = value;
}
}
Keep in mind that the renderMode is originally based on whether the font is italic, bold, strikeout, or underline, which I don't really see how those relate to renderMode, in XGraphicsPdfRenderer.cs:
//bool bold = (font.Style & XFontStyle.Bold) != 0;
//bool italic = (font.Style & XFontStyle.Italic) != 0;
bool italicSimulation = (font.GlyphTypeface.StyleSimulations & XStyleSimulations.ItalicSimulation) != 0;
bool boldSimulation = (font.GlyphTypeface.StyleSimulations & XStyleSimulations.BoldSimulation) != 0;
bool strikeout = (font.Style & XFontStyle.Strikeout) != 0;
bool underline = (font.Style & XFontStyle.Underline) != 0;
Realize(font, brush, boldSimulation ? 2 : 0);
Class and enum:
public class XGraphicsPdfRendererOptions
{
public XGraphicsPdfRenderMode RenderMode { get; set; }
public bool IncludeRenderModeForPage { get; set; }
public bool IncludeRenderModeForObject { get; set; }
}
public enum XGraphicsPdfRenderMode
{
Text_Render_Mode_Fill = 0,
Text_Render_Mode_Stroke = 1,
Text_Render_Mode_Fill_Stroke = 2,
Text_Render_Mode_Invisible = 3
}
Usage:
gfx.RenderOptions = new XGraphicsPdfRendererOptions() { RenderMode = XGraphicsPdfRenderMode.Text_Render_Mode_Fill, IncludeRenderModeForPage = true };
https://github.com/zaryk/PDFsharp

I've happened across this issue a couple of times now on separate projects. I found that the simplest fix is to dispose of the XGraphics object and then simply re-instantiate it using your current PdfPage instance.
PdfSharp.Pdf.PdfPage Page = Document.AddPage();
PdfSharp.Drawing.XGraphics gfx = PdfSharp.Drawing.XGraphics.FromPdfPage(Page);
//Build your pdf here until transparency issue occurs
//Issue has occured so re-instantiate gfx object
gfx.Dispose();
gfx = PdfSharp.Drawing.XGraphics.FromPdfPage(Page);
//Continue as normal

Below is the code I use to hide something in document and edit the document and again save. Let me know if it helps you
private PdfDocument FormatPdfDocument(PdfDocument document, List<string> packingTypes, string carrierName)
{
XFont PackingTypeFont = new XFont("Calibri", 10, XFontStyle.Bold);
var i = 0;
foreach (PdfPage page in document.Pages)
{
using (var gfx = XGraphics.FromPdfPage(page))
{
var packingType = packingTypes.ElementAtOrDefault(i++) ?? "PackingType Not Found";
if (carrierName == "xxxx")
{
var packingTypeBounds = new XRect(64, 62, 200, 12);
gfx.DrawRectangle(XBrushes.White, packingTypeBounds);
gfx.DrawString(packingType, PackingTypeFont, XBrushes.Black, packingTypeBounds, XStringFormats.TopLeft);
var logoBounds = new XRect(0, 0, 130, 50);
gfx.DrawRectangle(XBrushes.White, logoBounds);
}
else if (carrierName == "yyyy")
{
var packingTypeBounds = new XRect(200, 0, 200, 12);
gfx.DrawString(packingType, PackingTypeFont, XBrushes.Black, packingTypeBounds, XStringFormats.TopLeft);
}
else if (carrierName == "zzzz")
{
var packingTypeBounds = new XRect(410, 20, 200, 12);
var state = gfx.Save();
gfx.RotateAtTransform(90, new XPoint { X = 410, Y = 20 });
gfx.DrawString(packingType, PackingTypeFont, XBrushes.Black, packingTypeBounds, XStringFormats.TopLeft);
gfx.Restore(state);
}
}
}
return document;
}
This works fine for me till date without any issues

Some possible causes to answer your question "What would cause this?":
Are you using the latest version PDFsharp 1.50 beta 3b?
IIRC there is a bug in 1.32 that can lead to unexpected behavior because some properties are not reset.
Since you see the rectangle this might be the cause.
Since you see the rectangle, this probably does not apply:
There are two ways of modifying existing pages: "append" and "prepend". Your code snippet does not show how you do it.
With "prepend" your lime rectangle could be hidden under a white filled rectangle. Watch the PDF in Adobe Reader with active Transparency Grid and check that you see the grid where the rectangle should be.
Since you see the rectangle, this probably does not apply:
Maybe your text goes to the wrong position. Check the MediaBox and CropBox settings of the PDF page you are modifying. Normally pages start at (0,0), but you cannot be sure.
Locate your text in the PDF file and compare the text position with MediaBox and CropBox.
It could be an unknown bug in PDFsharp. If you do not find a PDF that allows to replicate the issue which you can share then it will be very difficult to fix the bug. But maybe one of the options above leads to success.

So I managed to find a way to make it work. I ran the stamping process twice on the document and it worked as expected. Fortunately, stamping twice does not affect regular documents which actually work normally.

Still an issue in 1.50 for some PDF files...
As a workaround, I create a PNG file using System.Drawing.DrawString.
Bitmap bmp = new Bitmap((int)p.Width.Point, 30);
Graphics gra = Graphics.FromImage(bmp);
gra.DrawString("Hello world", new Font("Verdana", 20), Brushes.Red, new PointF(0, 0));
bmp.Save("test.png", System.Drawing.Imaging.ImageFormat.Png);
Then I use XGraphics.DrawImage from this PNG file.
XGraphics xg = XGraphics.FromPdfPage(p, XGraphicsPdfPageOptions.Append);
XImage xi = XImage.FromFile("test.png");
// Add it at the bottom of the page
xg.DrawImage(xi, 0, p.Height-32, p.Width, 30);
This always ends up on top.