Settings.cs

using System;
using System.Windows.Forms; 

using System.Reflection;              // change column width of a propertygrid

namespace GrzBeamProfiler
{
    public partial class Settings: Form
    {
        public AppSettings Setting;

        public Settings(AppSettings settings)
        {
            InitializeComponent();
            this.propertyGrid.SelectedObject = settings;
        }

        // end settings dialog with ok
        private void buttonOk_Click( object sender, EventArgs e )
        {
            Setting = (AppSettings)this.propertyGrid.SelectedObject;
        }

        // change column width of a propertygrid: https://stackoverflow.com/questions/12447156/how-can-i-set-the-column-width-of-a-property-grid 2nd answer
        public static void SetLabelColumnWidth( PropertyGrid grid, int width )
        {
            if ( grid == null )
                return;
            FieldInfo fi = grid.GetType().GetField("gridView", BindingFlags.Instance | BindingFlags.NonPublic);
            if ( fi == null )
                return;
            Control view = fi.GetValue(grid) as Control;
            if ( view == null )
                return;
            MethodInfo mi = view.GetType().GetMethod("MoveSplitterTo", BindingFlags.Instance | BindingFlags.NonPublic);
            if ( mi == null )
                return;
            mi.Invoke(view, new object[] { width });
        }
        private void Settings_Load( object sender, EventArgs e )
        {
            SetLabelColumnWidth(this.propertyGrid, 180);
        }

    }
}