I want to use a custom font for my WindowsForm.
For this purpose, I added the font to the program as follows.

And I used the following code to change the font of all the controls.

public void SetFontControls()

    {
        var privatefontcollection = new PrivateFontCollection();
        var fontLength = Properties.Resources.IRANSans.Length;
        var fontData = Properties.Resources.IRANSans;
        var data = Marshal.AllocCoTaskMem(fontLength);
        Marshal.Copy(fontData, 0, data, fontLength);
        privatefontcollection.AddMemoryFont(data, fontLength);
        Marshal.FreeCoTaskMem(data);

        foreach (Control c in Controls)
        {
            c.Font = new Font(privatefontcollection.Families[0], 12);


        }
    }

I called this code in the Function load Form.

 private void FormHydro_Load(object sender, EventArgs e)
    {
        SetFontControls();
        
    }

But the problem is that the size changes all Controls but the font does not change.
I tried different fonts but nothing changes.