图片处理类

/*****************************************************************
 * 创建人：sunwugang
 * 主要作用：图片处理类
 * 1、生成缩略图片或按照比例改变图片的大小和画质  
 * 2、将生成的缩略图放到指定的目录下  
 *  创建日期：2018-07-27
 *****************************************************************/
namespace KK.TriageSys.Helper
{
    using System;
    using System.Drawing;
    using System.Drawing.Imaging;

    public class ImageHelper
    {
        private static ImageHelper instance;
        public static ImageHelper Instance
        {
            get
            {
                if (instance == null) instance = new ImageHelper();
                return ImageHelper.instance;
            }
        }

        //图片宽
        private int ImageWidth;
        /// <summary>
        /// 图片高
        /// </summary>
        private int ImageHeight;

        /// <summary>   
        /// 根据文件路径获取图片对象   
        /// </summary>   
        /// <param name="ImageFileName">图片文件的全路径名称</param>   
        public Image GetImageByPath(string ImageFileName)
        {
            return Image.FromFile(ImageFileName);
        }

        public bool ThumbnailCallback()
        {
            return false;
        }

        /// <summary>   
        /// 生成缩略图重载方法1，返回缩略图的Image对象   
        /// </summary>   
        /// <param name="img">图片对象</param>   
        /// <param name="Width">缩略图的宽度</param>   
        /// <param name="Height">缩略图的高度</param>   
        /// <returns>缩略图的Image对象</returns>   
        public Image GetReducedImage(Image img,int Width, int Height)
        {
            try
            {
                Image.GetThumbnailImageAbort callb = new Image.GetThumbnailImageAbort(ThumbnailCallback);
                return img.GetThumbnailImage(Width, Height, callb, IntPtr.Zero);
            }
            catch (Exception ex)
            {
                LogHelper.Default.SaveText("ImageHelper  GetReducedImage:" + ex.Message + ex.StackTrace);
                return null;
            }
        }

        /// <summary>   
        /// 生成缩略图重载方法2，将缩略图文件保存到指定的路径   
        /// </summary>   
        /// <param name="img">图片对象</param>   
        /// <param name="Width">缩略图的宽度</param>   
        /// <param name="Height">缩略图的高度</param>   
        /// <param name="targetFilePath">缩略图保存的全文件名，(带路径)，参数格式：D:Images ilename.jpg</param>   
        /// <returns>成功返回true，否则返回false</returns>   
        public bool GetReducedImage(Image img, int Width, int Height, string targetFilePath)
        {
            try
            {
                Image ReducedImage;
                Image.GetThumbnailImageAbort callb = new Image.GetThumbnailImageAbort(ThumbnailCallback);
                ReducedImage = img.GetThumbnailImage(Width, Height, callb, IntPtr.Zero);
                ReducedImage.Save(@targetFilePath, ImageFormat.Jpeg);
                ReducedImage.Dispose();
                return true;
            }
            catch (Exception ex)
            {
                LogHelper.Default.SaveText("ImageHelper  GetReducedImage:" + ex.Message + ex.StackTrace);
                return false;
            }
        }

        /// <summary>   
        /// 生成缩略图重载方法3，返回缩略图的Image对象   
        /// </summary>   
        /// <param name="img">图片对象</param>   
        /// <param name="Percent">缩略图的宽度百分比 如：需要百分之80，就填0.8</param>     
        /// <returns>缩略图的Image对象</returns>   
        public Image GetReducedImage(Image img, double Percent)
        {
            try
            {
                Image ReducedImage;
                Image.GetThumbnailImageAbort callb = new Image.GetThumbnailImageAbort(ThumbnailCallback);
                ImageWidth = Convert.ToInt32(img.Width * Percent);
                ImageHeight = Convert.ToInt32(img.Width * Percent);
                ReducedImage = img.GetThumbnailImage(ImageWidth, ImageHeight, callb, IntPtr.Zero);
                return ReducedImage;
            }
            catch (Exception ex)
            {
                LogHelper.Default.SaveText("ImageHelper  GetReducedImage:" + ex.Message + ex.StackTrace);
                return null;
            }
        }

        /// <summary>   
        /// 生成缩略图重载方法4，返回缩略图的Image对象   
        /// </summary>   
        /// <param name="img">图片对象</param>   
        /// <param name="Percent">缩略图的宽度百分比 如：需要百分之80，就填0.8</param>     
        /// <param name="targetFilePath">缩略图保存的全文件名，(带路径)，参数格式：D:Images ilename.jpg</param>   
        /// <returns>成功返回true,否则返回false</returns>   
        public bool GetReducedImage(Image img, double Percent, string targetFilePath)
        {
            try
            {
                Image ReducedImage;
                Image.GetThumbnailImageAbort callb = new Image.GetThumbnailImageAbort(ThumbnailCallback);
                ImageWidth = Convert.ToInt32(img.Width * Percent);
                ImageHeight = Convert.ToInt32(img.Width * Percent);
                ReducedImage = img.GetThumbnailImage(ImageWidth, ImageHeight, callb, IntPtr.Zero);
                ReducedImage.Save(@targetFilePath, ImageFormat.Jpeg);
                ReducedImage.Dispose();
                return true;
            }
            catch (Exception ex)
            {
                LogHelper.Default.SaveText("ImageHelper  GetReducedImage:" + ex.Message + ex.StackTrace);
                return false;
            }
        }

    }
}