Font Metrics Using oldschool API

gistfile1.txt

namespace pinvokeGetTextMetrics
{
    using System;
    using System.Collections.Generic;
    using System.Text;
    using System.Drawing;
    using System.Runtime.InteropServices;

    class pinvokeMapped {
   
        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        internal struct TEXTMETRIC
        {
           public int tmHeight;
           public int tmAscent;
           public int tmDescent;
           public int tmInternalLeading;
           public int tmExternalLeading;
           public int tmAveCharWidth;
           public int tmMaxCharWidth;
           public int tmWeight;
           public int tmOverhang;
           public int tmDigitizedAspectX;
           public int tmDigitizedAspectY;
           public char tmFirstChar;
           public char tmLastChar;
           public char tmDefaultChar;
           public char tmBreakChar;
           public byte tmItalic;
           public byte tmUnderlined;
           public byte tmStruckOut;
           public byte tmPitchAndFamily;
           public byte tmCharSet;
        };

        public static TEXTMETRIC GetTextMetrics(Graphics graphics, Font font) 
        { 
           IntPtr hDC = graphics.GetHdc(); 
           TEXTMETRIC textMetric; 
           IntPtr hFont = font.ToHfont(); 
           try 
           { 
             IntPtr hFontPreviouse = SelectObject(hDC, hFont); 
             bool result = GetTextMetrics(hDC, out textMetric); 
             SelectObject(hDC, hFontPreviouse); 
           } 
           finally 
           {  
             DeleteObject(hFont); 
             graphics.ReleaseHdc(hDC); 
           } 
           return textMetric; 
        }

        [DllImport("Gdi32.dll", CharSet=CharSet.Auto)] 
        public static extern IntPtr SelectObject(IntPtr hdc, IntPtr hgdiobj); 

        [DllImport("Gdi32.dll", CharSet=CharSet.Auto)] 
        public static extern bool GetTextMetrics(IntPtr hdc, out TEXTMETRIC lptm); 

        [DllImport("Gdi32.dll", CharSet=CharSet.Auto)] 
        public static extern bool DeleteObject(IntPtr hdc); 
    }

    partial class Form1
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
        {
            base.OnPaint(e);
            Graphics g = e.Graphics;

            FontFamily fontFamily = new FontFamily("Liberation Sans");
            Font liberation = new Font(fontFamily, 16, FontStyle.Regular, GraphicsUnit.Pixel);

            pinvokeMapped.TEXTMETRIC liberationMetrics = pinvokeMapped.GetTextMetrics(g, liberation);
            g.DrawString("Liberation Sans Metrics on this GC: tmAscent: " + liberationMetrics.tmAscent +
                " tmDescent: " + liberationMetrics.tmDescent + 
                " tmHeight " + liberationMetrics.tmHeight,
               liberation, System.Drawing.Brushes.Blue, new Point(30, 30));
        }

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.SuspendLayout();
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(677, 211);
            this.Name = "Form1";
            this.Text = "Form1";
            this.ResumeLayout(false);

        }

        #endregion
    }
}