dpihelper.cs

在windows mobile 5上的地图查看器

#region Using directives

using System;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;

#endregion

namespace PocketEarth
{
    /// <summary>
    /// A helper object to adjust the sizes of controls based on the DPI.
    /// </summary>
    public class DpiHelper
    {
        /// <summary>
        /// The real dpi of the device.
        /// </summary>
        private static int dpi = SafeNativeMethods.GetDeviceCaps(IntPtr.Zero, /*LOGPIXELSX*/88);

        /// <summary>
        /// Adjust the sizes of controls to account for the DPI of the device.
        /// </summary>
        /// <param name="parent">The parent node of the tree of controls to adjust.</param>
        public static void AdjustAllControls(Control parent)
        {
            if (dpi == 96)
            {
                return;
            }
            foreach (Control child in parent.Controls)
            {
                AdjustControl(child);
                AdjustAllControls(child);
            }
        }



        public static void AdjustControl(Control control)
        {
            control.Bounds = new Rectangle(
                  control.Left   * dpi / 96,
                  control.Top    * dpi / 96,
                  control.Width  * dpi / 96,
                  control.Height * dpi / 96 );
        }


        /// <summary>
        /// Scale a coordinate to account for the dpi.
        /// </summary>
        /// <param name="x">The number of pixels at 96dpi.</param>
        /// <returns></returns>
        public static int Scale(int x)
        {
            return x * dpi / 96;
        }


        private class SafeNativeMethods
        {
            [DllImport("coredll.dll")]
            static internal extern int GetDeviceCaps(IntPtr hdc, int nIndex);
        }
    }


}