What is the IO helper class? Example introduction of IO help class (with code)

The content of this article is to introduce what is the IO help class? Example introduction of IO helper class (with code). It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

using System;
using System.IO;
using System.Web;
using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;
using System.Xml.Serialization;

namespace ZMM.Core
{
    /// <summary>
    /// IO帮助类
    /// </summary>
    public class IOHelper
    {
        //是否已经加载了JPEG编码解码器
        private static bool _isloadjpegcodec = false;
        //当前系统安装的JPEG编码解码器
        private static ImageCodecInfo _jpegcodec = null;

        /// <summary>
        /// 获得文件物理路径
        /// </summary>
        /// <returns></returns>
        public static string GetMapPath(string path)
        {
            if (HttpContext.Current != null)
            {
                return HttpContext.Current.Server.MapPath(path);
            }
            else
            {
                return System.Web.Hosting.HostingEnvironment.MapPath(path);
            }
        }

        #region  序列化

        /// <summary>
        /// XML序列化
        /// </summary>
        /// <param>序列对象
        /// <param>XML文件路径
        /// <returns>是否成功</returns>
        public static bool SerializeToXml(object obj, string filePath)
        {
            bool result = false;

            FileStream fs = null;
            try
            {
                fs = new FileStream(filePath, FileMode.Create, FileAccess.Write, FileShare.ReadWrite);
                XmlSerializer serializer = new XmlSerializer(obj.GetType());
                serializer.Serialize(fs, obj);
                result = true;
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                if (fs != null)
                    fs.Close();
            }
            return result;

        }

        /// <summary>
        /// XML反序列化
        /// </summary>
        /// <param>目标类型(Type类型)
        /// <param>XML文件路径
        /// <returns>序列对象</returns>
        public static object DeserializeFromXML(Type type, string filePath)
        {
            FileStream fs = null;
            try
            {
                fs = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
                XmlSerializer serializer = new XmlSerializer(type);
                return serializer.Deserialize(fs);
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                if (fs != null)
                    fs.Close();
            }
        }

        #endregion

        #region  水印,缩略图

        /// <summary>
        /// 获得当前系统安装的JPEG编码解码器
        /// </summary>
        /// <returns></returns>
        public static ImageCodecInfo GetJPEGCodec()
        {
            if (_isloadjpegcodec == true)
                return _jpegcodec;

            ImageCodecInfo[] codecsList = ImageCodecInfo.GetImageEncoders();
            foreach (ImageCodecInfo codec in codecsList)
            {
                if (codec.MimeType.IndexOf("jpeg") > -1)
                {
                    _jpegcodec = codec;
                    break;
                }

            }
            _isloadjpegcodec = true;
            return _jpegcodec;
        }

        /// <summary>
        /// 生成缩略图
        /// </summary>
        /// <param>图片路径
        /// <param>缩略图路径
        /// <param>缩略图宽度
        /// <param>缩略图高度
        /// <param>生成缩略图的方式   
        public static void GenerateThumb(string imagePath, string thumbPath, int width, int height, string mode)
        {
            Image image = Image.FromFile(imagePath);

            string extension = imagePath.Substring(imagePath.LastIndexOf(".")).ToLower();
            ImageFormat imageFormat = null;
            switch (extension)
            {
                case ".jpg":
                case ".jpeg":
                    imageFormat = ImageFormat.Jpeg;
                    break;
                case ".bmp":
                    imageFormat = ImageFormat.Bmp;
                    break;
                case ".png":
                    imageFormat = ImageFormat.Png;
                    break;
                case ".gif":
                    imageFormat = ImageFormat.Gif;
                    break;
                default:
                    imageFormat = ImageFormat.Jpeg;
                    break;
            }

            int toWidth = width > 0 ? width : image.Width;
            int toHeight = height > 0 ? height : image.Height;

            int x = 0;
            int y = 0;
            int ow = image.Width;
            int oh = image.Height;

            switch (mode)
            {
                case "HW"://指定高宽缩放（可能变形）           
                    break;
                case "W"://指定宽，高按比例             
                    toHeight = image.Height * width / image.Width;
                    break;
                case "H"://指定高，宽按比例
                    toWidth = image.Width * height / image.Height;
                    break;
                case "Cut"://指定高宽裁减（不变形）           
                    if ((double)image.Width / (double)image.Height > (double)toWidth / (double)toHeight)
                    {
                        oh = image.Height;
                        ow = image.Height * toWidth / toHeight;
                        y = 0;
                        x = (image.Width - ow) / 2;
                    }
                    else
                    {
                        ow = image.Width;
                        oh = image.Width * height / toWidth;
                        x = 0;
                        y = (image.Height - oh) / 2;
                    }
                    break;
                default:
                    break;
            }

            //新建一个bmp
            Image bitmap = new Bitmap(toWidth, toHeight);

            //新建一个画板
            Graphics g = Graphics.FromImage(bitmap);

            //设置高质量插值法
            g.InterpolationMode = InterpolationMode.High;

            //设置高质量,低速度呈现平滑程度
            g.SmoothingMode = SmoothingMode.HighQuality;

            //清空画布并以透明背景色填充
            g.Clear(Color.Transparent);

            //在指定位置并且按指定大小绘制原图片的指定部分
            g.DrawImage(image,
                        new Rectangle(0, 0, toWidth, toHeight),
                        new Rectangle(x, y, ow, oh),
                        GraphicsUnit.Pixel);

            try
            {
                bitmap.Save(thumbPath, imageFormat);
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                if (g != null)
                    g.Dispose();
                if (bitmap != null)
                    bitmap.Dispose();
                if (image != null)
                    image.Dispose();
            }
        }

        /// <summary>
        /// 生成图片水印
        /// </summary>
        /// <param>源图路径
        /// <param>水印图片路径
        /// <param>保存路径
        /// <param>位置
        /// <param>透明度
        /// <param>质量
        public static void GenerateImageWatermark(string originalPath, string watermarkPath, string targetPath, int position, int opacity, int quality)
        {
            Image originalImage = null;
            Image watermarkImage = null;
            //图片属性
            ImageAttributes attributes = null;
            //画板
            Graphics g = null;
            try
            {

                originalImage = Image.FromFile(originalPath);
                watermarkImage = new Bitmap(watermarkPath);

                if (watermarkImage.Height >= originalImage.Height || watermarkImage.Width >= originalImage.Width)
                {
                    originalImage.Save(targetPath);
                    return;
                }

                if (quality  100)
                    quality = 80;

                //水印透明度
                float iii;
                if (opacity > 0 && opacity 
        /// 生成文字水印
        /// 
        /// <param>源图路径
        /// <param>保存路径
        /// <param>水印文字
        /// <param>文字大小
        /// <param>文字字体
        /// <param>位置
        /// <param>质量
        public static void GenerateTextWatermark(string originalPath, string targetPath, string text, int textSize, string textFont, int position, int quality)
        {
            Image originalImage = null;
            //画板
            Graphics g = null;
            try
            {
                originalImage = Image.FromFile(originalPath);
                //画板
                g = Graphics.FromImage(originalImage);
                if (quality  100)
                    quality = 80;

                Font font = new Font(textFont, textSize, FontStyle.Regular, GraphicsUnit.Pixel);
                SizeF sizePair = g.MeasureString(text, font);

                float x = 0;
                float y = 0;

                switch (position)
                {
                    case 1:
                        x = (float)originalImage.Width * (float).01;
                        y = (float)originalImage.Height * (float).01;
                        break;
                    case 2:
                        x = ((float)originalImage.Width * (float).50) - (sizePair.Width / 2);
                        y = (float)originalImage.Height * (float).01;
                        break;
                    case 3:
                        x = ((float)originalImage.Width * (float).99) - sizePair.Width;
                        y = (float)originalImage.Height * (float).01;
                        break;
                    case 4:
                        x = (float)originalImage.Width * (float).01;
                        y = ((float)originalImage.Height * (float).50) - (sizePair.Height / 2);
                        break;
                    case 5:
                        x = ((float)originalImage.Width * (float).50) - (sizePair.Width / 2);
                        y = ((float)originalImage.Height * (float).50) - (sizePair.Height / 2);
                        break;
                    case 6:
                        x = ((float)originalImage.Width * (float).99) - sizePair.Width;
                        y = ((float)originalImage.Height * (float).50) - (sizePair.Height / 2);
                        break;
                    case 7:
                        x = (float)originalImage.Width * (float).01;
                        y = ((float)originalImage.Height * (float).99) - sizePair.Height;
                        break;
                    case 8:
                        x = ((float)originalImage.Width * (float).50) - (sizePair.Width / 2);
                        y = ((float)originalImage.Height * (float).99) - sizePair.Height;
                        break;
                    case 9:
                        x = ((float)originalImage.Width * (float).99) - sizePair.Width;
                        y = ((float)originalImage.Height * (float).99) - sizePair.Height;
                        break;
                }

                g.DrawString(text, font, new SolidBrush(Color.White), x + 1, y + 1);
                g.DrawString(text, font, new SolidBrush(Color.Black), x, y);

                //保存图片
                EncoderParameters encoderParams = new EncoderParameters();
                encoderParams.Param[0] = new EncoderParameter(Encoder.Quality, new long[] { quality });
                if (GetJPEGCodec() != null)
                    originalImage.Save(targetPath, _jpegcodec, encoderParams);
                else
                    originalImage.Save(targetPath);
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                if (g != null)
                    g.Dispose();
                if (originalImage != null)
                    originalImage.Dispose();
            }
        }

        #endregion
    }
}

The above is the detailed content of What is the IO helper class? Example introduction of IO help class (with code). For more information, please follow other related articles on the PHP Chinese website!