In my WinForm app I draw into a System.Drawing.Bitmap. I create fonts from a LOGFONT and draw using the GDI function ExtTextOutW. However the output is terrible. It has bad jaggies and looks like the antialiaser was on LSD. Reading around this seems a common issue - is there a resolution?
If I use:
lf.lfQuality = FontQuality.NONANTIALIASED_QUALITY
when I create the font then the horrible jaggies go away but of course there is no antialiasing.
Is there a way to create smooth text in a Bitmap with ExtTextOutW?
It is possible but a bit tricky and it can't have transparent background.
You will need to:
Create in-memory bitmap buffer that is compatible with display device context (IntPtr.Zero handle)
Fill the buffer background with solid color or other background
Render the text into the memory bitmap
Copy from in-memory bitmap to image device context (BitBlt)
See GDI text rendering to image for more details.
I have a PictureBox pic , and an Image img, pic.Image = img
and I draw some rectangles on the Image using
Graphics g = Grpahics.FromImage(pic.Image);
g.DrawRectangle(...);
But at one point, I want to remove the rectangle from the Image,I tried
pic.Image = getOriginalImage();
pic.Refresh();
but the image remains the same(Rectangles are still on top of the Image)
I know there's a method graphics.Clear(Color),but it replace the entire Image with a solid color
How do I remove the drawing only from the PictureBox?
Thanks
Edit:
I already saved the original and when I erase I use the original image
You are overwriting the original image. Save the image locally and clone it into the PictureBox.Image property. Then clone again when you want to erase
Draw the background image again using Graphics.DrawImage() or assign the image again to the Image property. Using a Graphics object in this way is writing directly to the image displayed in the PictureBox and it does not keep separate copies of what is written using a Graphics object and the background Image.
I am making a logical gates application and I can currently drag out bitmaps into the picturebox. These bitmaps are the logical gates. Now I need a way to draw the lines to connect inputs with gates. I would like to have the line sort of stick to connection or anchor points on the bitmap that I place but I have no idea how to do this.
Each bitmap dragged out is an object with a size and an x y position.
Thanks for any help! I have been searching for a solution for a while now.
I basically ended up making 10x10 rectangles positioned according to the height/width of the object that would update when the bitmap was moved. The bitmap was also its own rectangle.
I want to get the colors of the center bottom part of a BMP image. How this can be done, I need some techniques.
Check out the Bitmap class. It has a GetPixel() method which takes X/Y coordinates and returns the color of that pixel.
http://msdn.microsoft.com/en-us/library/system.drawing.bitmap.getpixel%28v=VS.100%29.aspx
If this isn't enough, you'll have to describe more of what you are trying to accomplish.
This is the high level problem I'm trying to solve...
I have a 3rd party plotting/graphing (IoComp Plot), and I want to embed a high quality (at least 600 dpi) bitmap of the Plot control in reports created by another 3rd party report package (Combit List & Label).
This is the approach that seems most promising so far...
---Edit---:
After trying many other approachs, the only one that I think I can make work is to create a hidden instance of the Plot control, with everything scaled up to printer size (approx 5 times screen size). That includes width and height, font sizes, line widths - every visible component of the control. Yuck!
------
I can get a Graphics object of the proper resolution from the plot control's PrintPage event, but converting it to a Bitmap so the report package will be happy is proving to be the major stumbling block. Several hours of searching has led to other people who asked the same question, but no viable answers.
The only promising lead I've found suggested using one of the Bitmap constructors, which takes a Graphics instance as a parameter.
However, it's not working for me. It creates Bitmap, but with no content from the Plot control - it is a pure black image.
Here's my code (edited to show drawing of red line to Graphics object):
void PrintDocument_PrintPage(object sender, PrintPageEventArgs e)
{
// Draw a red line on the Graphics object. When printed, this
// line is shown as part of the normal Plot graphics.
Pen myPen;
myPen = new Pen(Color.Red);
e.Graphics.DrawLine(myPen, 0, 0, 200, 200);
myPen.Dispose();
// Create a bitmap from the Graphics object
Bitmap bm = new Bitmap(1000, 1000, e.Graphics);
// Save to disk
// DOES NOT WORK - CREATES FILE THAT IS PURE BLACK (VIEWED
// WITH "PAINT" PROGRAM)
bm.Save(#"C:\Bicw_Dev\Bic.Net\FrontEnd\GraphicsToBmp.bmp", ImageFormat.Bmp);
bm.Dispose();
}
Can anyone suggest why this doesn't work? Is this even a valid approach?
Also, please note:
As far as I can determine (and I've spent quite a bit of time looking) there is no way to get a high resolution, print quality Bitmap from the Plot control directly!
I stress this because several others who asked the question got code samples in response that solved the opposite problem - converting a Bitmap to a Graphics.
I need to convert a Graphics object to a Bitmap object.
And if anyone can suggest an alternate approach that allows me to get a print quality image of my plots into my reports, please feel free. (For example, I can get a low quality (72 bpi) Bitmap from the Plot control, and have considered trying to stretch it - but I've never seen that approach work well in other applications).
Thanks,
-Tom Bushell
Edit in response to comment:
As an experiment, I added the following:
Pen myPen;
myPen = new Pen(Color.Red);
e.Graphics.DrawLine(myPen, 0, 0, 200, 200);
myPen.Dispose();
This caused a red line to be drawn over the plot graphics when I printed my plot. But it had no effect on the Bitmap - it's still pure black.
However, it's not working for me. It
creates Bitmap, but with no content
from the Plot control - it is a pure
black image.
Well you never do paint to the graphics, what do you expect?
You are suppose to do the actual drawing for the output in that event.
The constructor you're using does not copy any graphics, only sets the resolution equal to the graphics resolution. See msdn. As Leppie points out, you have to actually draw something to the bitmap. I suggest getting another graphics object for the item you just created.
Graphics g = Graphics.FromImage(bmp);
//Make the background white
g.FillRectangle(Brushes.White, 0, 0, 1000, 1000);
It is not easy to control the DPI in the Print(Preview) system.
But maybe you are going about it the wrong way. What you want is to create a (large) bitmap and then 'trick' the control in to using that bitmap as if it was the screen. See this list of links.
No need for PrintDocument.