我如何从Visual Studio（c＃）的显示设置中读取屏幕缩放比例（100％，125％，...）

Question

I have looked at every similar question and none work for me. I am programming a winForm that will show me the screen factor. I have tryed reading from Registry (doesnt work) i have tryed using DLL "gdi32.dll" , that works but only on Win10 not on Win7. I Have also tryed :

float dpiX, dpiY;
using (Graphics graphics = Graphics.FromHwnd(IntPtr.Zero))
{
    dpiX = graphics.DpiX;
    dpiY = graphics.DpiY;
}

but it doesnt work also. I know that this question is repeated but all the answers that were in the previous questions didnt help, so thats why i am opening a new one. So, can someone help me please?

Answer 1

You can use GetDpiForWindow with a Manifest.

uint nDPI = GetDpiForWindow(this.Handle);

I get =>

        100% : 96
        125% : 120
        150% : 144
        175% : 168

Declaration =>

    [DllImport("User32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
    public static extern uint GetDpiForWindow(IntPtr hwnd);

Manifest =>

  <application xmlns="urn:schemas-microsoft-com:asm.v3">
    <windowsSettings>
      <dpiAware xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">true/PM</dpiAware>
      <dpiAwareness xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">PerMonitor</dpiAwareness>
     </windowsSettings>
  </application>