I am trying to take screenshots of every screen on my windows 10 machine. My system has 2 monitors which are of multiple DPIs.
I am trying to use C# to take a screenshot of every single monitor. However my scaled monitor is reporting the wrong coordinates: Everything is halved. As a result, the primary monitor's screenshot is only 1/4th of the screen area (width/2,height/2).
Here is my code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Drawing;
using System.Drawing.Imaging;
namespace CsSourceClient
{
class Program
{
static void Main(string[] args)
{
Screen[] screens;
screens = Screen.AllScreens;
int i = 0;
foreach (var screen in System.Windows.Forms.Screen.AllScreens)
{
var savePath = "monitor" + i+".jpg";
var x = screen.Bounds.Location.X;
var y = screen.Bounds.Location.Y;
var w = screen.Bounds.Width;
var h = screen.Bounds.Height;
Console.Out.WriteLine("Monitor: " + i + " extents:" + x + "," + y + " " + w + "," + h);
using (Bitmap bmp = new Bitmap(w, h))
{
using (Graphics g = Graphics.FromImage(bmp))
{
g.CopyFromScreen(x, y, 0, 0, bmp.Size);
}
bmp.Save(savePath, ImageFormat.Jpeg);
Console.Out.WriteLine("saved: " + savePath);
}
i++;
}
}
}
}
PS: I get different values based on what I set "dpiaware" in the manifest file: https://social.msdn.microsoft.com/Forums/en-US/054c1d49-9f24-4617-aa83-9bc4f1bb4a5d/use-appmanifest-file-to-make-winforms-application-dpi-aware?forum=vbgeneral
If I don't set dpiaware, then the primary monitor's bounds get halved (cropping out 3/4ths of the screen). If I set dpiaware to true, then the secondary monitor's bounds get doubled (leaving big black areas in the screenshot).
As mentioned in the comments, the solution is to set the app.manifest dpiAware tag to "true/pm". The effect is different than just setting it to true.
<application xmlns="urn:schemas-microsoft-com:asm.v3">
<windowsSettings>
<dpiAware xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">true/pm</dpiAware>
</windowsSettings>
</application>