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Image Drawing with Graphics C# [closed]

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I want to draw a image in a picture box, and the image is not drawing what is wrong with my code? Thanks
Bitmap b;
private void Form1_Load(object sender, EventArgs e)
{
b = new Bitmap(1000, 100);
pictureBox1.Image = b;
Graphics g = pictureBox1.CreateGraphics();
Rectangle rect = new Rectangle(20, 20, 70, 70);
Image earth = Image.FromFile("" + System.IO.Directory.GetCurrentDirectory() + #"\earth.png");
g.DrawImage(earth,rect);
}

Form.Load fires before anything is drawn to the screen. When the Form is actually displayed for the first time, PictureBox.OnPaint will be called and the control will render itself with its default appearance. To properly draw to a PictureBox, handle its Paint event and do your drawing in the event handler using the supplied Graphics instance. That event will be fired every time any part of the control is redrawn, which will allow you to draw graphics that persist when the control is invalidated. See here for more information.

C# do something based on image detection [closed]

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I am making a program in C#. I want it to do something if image is detected on screen. For example let's say I am making a game bot. And my health is image on my screen filled with green color like so:
FULL HP BAR
And something took my hp to this level:
TAKEN HP BAR
If the C# detects the image with hp taken, do something ... Is this possible and how can i do it ? Thanks.

I wrote the bot for game. To detect when life become low you can scan a certain pixel color and test it with the sample value (for example you can capture pixel in the middle of your rectangle and if it is green you have more then half of life).
Also I made screenshots, cut some areas and kept them as bitmaps. In a game I loaded them, then I made screenshot every second and checked if some of these bitmaps appeared in the screenshot.
To capture the screen in C# you can use CopyFromScreen method of Graphics:
var screen = new Bitmap(Screen.PrimaryScreen.Bounds.Width,
Screen.PrimaryScreen.Bounds.Height,
PixelFormat.Format32bppArgb);
var graphics = Graphics.FromImage(screen );
graphics.CopyFromScreen(Screen.PrimaryScreen.Bounds.X,
Screen.PrimaryScreen.Bounds.Y,
0, 0,
Screen.PrimaryScreen.Bounds.Size,
CopyPixelOperation.SourceCopy);

Winforms multi-layer graphics [closed]

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Problem example:
I have a control do draw some geometrical shapes (I use panel).
I have drawn a line.
Now when I move cursor to one of the line tips I want that point to be "highlighted" (a solid circle drawn around it).
And when I move cursor off the point, I want the "highlighting" circle to be erased, but I do not want to redraw the line.
So, technically, I need two layers:
1-st layer to draw my line(s).
2-nd layer to draw/erase highlights.
I do not want the first layer to be redrawn every time when something is drawn/erased in the second layer.
Any suggestions?

Option 1: Nest another Panel in the bottom one. This is good for overlaying graphics including semi-transparency. (Nesting means: panel2.Parent = panel1) You can nest many layers if you want to.
Option 2: Draw into the BackgroundImage of the Panel and use drawing onto the surface for the interactivce stuff.
I noted that you 'don't want to draw the line again'. This is not what you would usually say/do/try when doing graphics. If you are serious about this go for option 2!
See here for the difference of drawing onto a control and into a Bitmap and here for another example of using option 2 to display a cross as a cursor above a Bitmap.
Btw, the two options are not mutually exclusive: You could nest Panels with BackgroundImages and draw interactive stuff on the topmost one..

#TaW pretty much answered it. I set an example:
For static drawing:
private Bitmap myStaticImage;
public Form2()
{
InitializeComponent();
this.myStaticImage = new Bitmap(200, 100);
Graphics g = Graphics.FromImage(this.myStaticImage);
g.DrawLine(Pens.Red, new Point(0, 0), new Point(200, 0));
this.panel1.BackgroundImage = this.myStaticImage;
}
For dynamic drawing:
private void panel1_Paint(object sender, PaintEventArgs e)
{
// Stuff
}
I recommend using a PictureBox or a UserControl with DoubleBuffered property set to true. Panel control is not double buffered and will flicker.

C# panel drawing on button press [closed]

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My apologies if I'm missing something simple here, but I've running in circles for some time now. In short, I'd like to update the panel graphics (panel will contain simple shapes like circles and rectangles) every time a button is pressed. The code would look something like this:
private void PanelGraphics()
{
ClearThePanel(); //empties the panel
FillThePanel(); //draws new shapes in the panel
}
The function would be then called every time a button is pressed, and I understand button_events well enough so that's not a problem. However, I have no idea how to pull off the PanelGraphics() function, and a few links about panel_paint events didn't help me much.

You can draw to the panel by creating a graphics controller to it.
Graphics g = panel.CreateGraphics();
You can then use the Graphic class's plethora of methods to draw whatever you want to the panel
g.DrawCurve(parameters);
g.DrawEllipse(parameters);
g.DrawLine(parameters);
g.DrawRectangle(parameters);
To clear the panel the easiest way is to draw a box the colour of the background to the panel
g.DrawRectangle(new Pen(panel.BackColor), new Rectangle(new Point(), panel.Size));

how to reduce Image width and height in c# asp.net? [closed]

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I am working on a project where have to display the images by using image path.
For this I write one method taking the image path as an argument.
My goal is to reduce the size of image(width and height)

If you pass the image into an instance of the WebImage Class you can do those things simply using the Resize method.
var webImage = new WebImage(image);
webImage.Resize(200, 200, false, true);
webImage.Save("~/path", "png", true);
In the example, image passed into the WebImage as a param could be a byte[] for the file or just a string path to the file. I set the image dimensions to 200*200 and saved it as a PNG.

What you're looking for is image resampling.
Here's a VERY quick and dirty way of resampling an image in C#.NET using Bilinear interpolation.
Bitmap bmpOriginal = Bitmap.FromFile("path_to_file");
Bitmap bmpResampled = new Bitmap(newWidth, newHeight);
Graphics g = Graphics.FromImage(bmpResampled);
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.Bilinear;
g.DrawImage(bmpOriginal, new Rectangle(0, 0, bmpResampled.Width + 1, bmpResampled.Height + 1));
Your resampled version will now be contained in bmpResampled.

If you just want to edit width and height without any complications and changing the actual size.
This is pure html way.
<img id="" src ="Your image path" height ="100" width = "100"></img>
or you can use an asp control
<asp:Image ID ="img" runat ="server" ImageUrl = "your path" Width ="100" Height ="100"/>
that is if your problem is this simple. Just put height and width values accordingly.