Capture a form to image - c#

I have a form with controls, I need capture this form to image. Please help me. Thanks.

//Control cntrl; previously declared and populated
Bitmap bmp = new Bitmap(cntrl.Width,cntrl.Height);
cntrl.DrawToBitmap(bmp, new Rectangle(Point.Empty, bmp.Size));

This works (almost) for me. I did note that MANY times the image would just be blank. When I searched online, it seems that many people were having this issue with the webBrowser control. It turns out that the initial image sometimes needs to be cleared to a solid color for this control. I really don't know why, but once it is initialized, I get much more consistent results. I've yet to get a blank image back.
Please note the code I've attached for clearing the initial image to all black.
try
{
string fn = Path.Combine(Path.GetTempPath(), "Error_screen.png");
Bitmap bmp = new Bitmap(internalBrowser.Width, internalBrowser.Height);
// In order to use DrawToBitmap, the image must have an INITIAL image.
// Not sure why. Perhaps it uses this initial image as a mask??? Dunno.
using (Graphics G = Graphics.FromImage(bmp))
{
G.Clear(Color.Black);
}
internalBrowser.DrawToBitmap(bmp, new Rectangle(0, 0,
internalBrowser.Width, internalBrowser.Height));
bmp.Save(fn, ImageFormat.Png);
}
catch
{
// handle exceptions here.
return "";
}
One VERY interesting side note (as compared to other solutions I've seen): This works for my control which is on a form that I have never shown! My form exists as a headless web browser, but this actual form has never seen the light of day.

Related

SVG rendering in C# with SVG library always fills shapes with black

I'm using the Svg.Core library (version 3.0.49.2) to render SVGs (defined in strings) to PNG images. No matter what I do, any shape seems to be rendered with a black stroke and a black fill.
Here's the code I'm using for a simple rectangle, as an example:
var svgString = #"<svg width=""300"" height=""300"" xmlns=""http://www.w3.org/2000/svg"" xmlns:xlink=""http://www.w3.org/1999/xlink""><rect x=""5"" y=""5"" height=""90"" width=""50"" fill=""#ef0000"" stroke=""#00ef00"" /></svg>";
var svgDocument = SvgDocument.FromSvg<SvgDocument>(svgString);
var bitmap = svgDocument.Draw();
bitmap.Save(fileName, ImageFormat.Png);
which ends up rendering a rectangle of the correct height and width, but all black:
I've seen a number of posts that mention various versions of inlining styles, but regardless of whether I'm using a style="" approach or a fill="", the problem continues. Also seems to happen without fill color specified or using standard color names instead of RGB values.
Any help or ideas are appreciated!
The best answer I have come up with here is from the comment earlier. If you put the following around it: svgDoc.Color = new SvgColourServer(Color.DarkGreen); svgDoc.StopColor = new SvgColourServer(Color.DarkGreen); svgDoc.Stroke = new SvgColourServer(Color.DarkGreen); svgDoc.Fill = new SvgColourServer(Color.DarkGreen); , you will get colors in the SVG. Posting this as the answer in case anyone runs into this issue down the road.

C# white or black unwanted pixels appear in the image

I am new to C#, I am using Visual Studo 2010, I have an image that needs to be displayed on a picturebox.
I tried many different methods. All the methods results in some unwanted pixels to appear along with image.
I have tried
picturebox.Image = Image.FromFile("bird.png");
result->
the image is displayed but with the stray white/black pixels at random places.
I also tried creating a bitmap of same size and drawing the image onto the bitmap and then assigning the bitmap to the picture box.Image. Still those unwanted pixels are visible.
I have tried clearing the picture box image (filling it with white or transparent) and then assigning the image, still same error occurs.
PS: this doesn't happen for all the images only certain images show this behaviour.
any help would be great
Code:
Image org = Bitmap.FromFile("bird.png");
Bitmap final = new Bitmap(org.Width,org.Height);
using (Graphics g = Graphics.FromImage(final))
{
g.DrawImage(org,0,0,GraphicsUnit.Pixel);
}
picturebox.Image = final;
if i use final.save("picture.png"). The "picuture.png" does not have that wrong pixels, it happens only when i use picture box to display it.
Please find the images attached defect orginal
PS: its not because of different fileformat (orginal and defect)
It was an TransperancyKey issue resolved by setting it to Default.

Why Isn't ControlPaint.DrawGrid Function not Displaying Anything to a PictureBox

I want to make a graph paper grid and set the drawing to the image of a picture box. Now I might even be using the wrong thing for drawing a graph paper grid but I have asked around and some people said that the DrawGrid method would work. None of the code below is returning any errors, but when I run the button1_Click method, it doesn't display anything to the picturebox.
private void button1_Click(object sender, EventArgs e)
{
button2.Visible = true;
Bitmap bmp = new Bitmap(pictureBox1.ClientSize.Width, pictureBox1.ClientSize.Height);
Size yourGridspacing = new Size((int)numericUpDown1.Value, (int)numericUpDown2.Value);
using (Graphics G = Graphics.FromImage(bmp))
{
ControlPaint.DrawGrid(G, new Rectangle(Point.Empty, bmp.Size), yourGridspacing , Color.Black);
}
pictureBox1.Image = bmp;
}
Any idea what the problem might be?
Your PictureBox probably has a White Background.. If so, please tell the ControlPaint.DrawGrid method so..:
ControlPaint.DrawGrid(G, new Rectangle(Point.Empty, bmp.Size),
yourGridspacing , Color.White);
The param doesn't control the color of the dots; it is supposed to help find a Color that will contrast. So maybe the best way to write it will be:
ControlPaint.DrawGrid(G, new Rectangle(Point.Empty, bmp.Size),
yourGridspacing, pictureBox1.BackColor);
This will work for all colors except Color.Transparent.. (in which case the Color of the control below will decide if the dots are visible..)
You may wonder, why such a roundabout way is chosen? Well, the method DrawGrid is not really meant as a normal drawing method, like the ones in Graphics. It is one of several methods that are meant to construct a robust display of Windows controls like Button or CheckBox.. Now, the Background over which the Grid is drawn need not have only one Color; it could be an Image or a Gradient and it could change..
You are supposed to pick a typical color to represent that background. The system will then choose a Color with good contrast for the dots.
For a way to control the grid's color see the last option in my other answer!

How to place a System.Drawing.Graphics object in browser window

I'd like to understand how to use C# for drawing an image in my browser window - alongside other HTML objects that are already there. (Idea: To place buttons and forms that allow the user to alter the image.)
I am doing this in Mono on Linux, but I'd like the thing to be portable.
What I came up with so far is:
public virtual void button1Clicked (object sender, EventArgs args)
{
int height = 300;
int width = 300;
Bitmap bmp = new Bitmap(width, height, PixelFormat.Format24bppRgb);
Graphics g = Graphics.FromImage(bmp);
//
//Draw something on g here
//
Response.ContentType = "image/gif";
bmp.Save(Response.OutputStream, ImageFormat.Gif);
g.Dispose();
bmp.Dispose;
}
This clears the browser window and then displays the image, which is not what I wanted.
After extensive search I found the following tutorial,
http://www.dreamincode.net/forums/topic/67275-the-wonders-of-systemdrawinggraphics/
which says I should try to use a Handle on some control in my window, alternatively the CreateGraphics() method. Neither of these seem to exist for my "button1" or any other id of an entity in my .aspx page. Is that because I'm using Mono?
To sum up, what is the best way to draw inside a browser window in C# + asp.net??
i had the same thing to do some time ago,
the thing is that you will have to save your graphic object/bitmap to a location if you want to use it in an iFrame or Image control.
If you don't want to save it to a location,
try using a server script on your page :
http://www.developerfusion.com/article/2569/creating-images-on-the-fly-with-aspnet/

.NET set image display size

I am using some custom controls one of which is a tooltip controller that can display images, so I am using th ebelow code to instantiate it:
Image newImage = Image.FromFile(imagePath);
e.ToolTipImage = newImage;
obviously could inline it but just testing at the moment. The trouble is the image is sometimes the wrong size, is there a way to set the display size. The only way I can currently see is editing the image using GDI+ or something like that. Seems like a lot of extra processing when I am only wanting to adjust display size not affect the actual image.
Once you have an image object loaded from its source, the Height and Width (and Size, and all ancillary properties) are read-only. Therefore, you are stuck with GDI+ methods for resizing it in RAM and then displaying it accordingly.
There are a lot of approaches you can take, but if you were to encapsulate that out to a library which you could reuse should this problem occur again, you'll be set to go. This isn't exactly optimized (IE, may have some bugs), but should give you an idea of how to approach it:
Image newImage = Image.FromFile(myFilePath);
Size outputSize = new Size(200, 200);
Bitmap backgroundBitmap = new Bitmap(outputSize.Width, outputSize.Height);
using (Bitmap tempBitmap = new Bitmap(newImage))
{
using (Graphics g = Graphics.FromImage(backgroundBitmap))
{
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
// Get the set of points that determine our rectangle for resizing.
Point[] corners = {
new Point(0, 0),
new Point(backgroundBitmap.Width, 0),
new Point(0, backgroundBitmap.Height)
};
g.DrawImage(tempBitmap, corners);
}
}
this.BackgroundImage = backgroundBitmap;
I did test this, and it worked. (It created a 200x200 resized version of one of my desktop wallpapers, then set that as the background image of the main form in a scratch WinForms project. You'll need using statements for System.Drawing and System.Drawing.Drawing2D.
In Winforms, if you contain the image inside a PictureBox control, the PictureBox control can be set to zoom to a particular height/width, and the image should conform.
At least that's what happened in my Head First C# book when I did the exercise.

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