using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;

namespace TProduct.Common
{
    public class ImageHelper
    {      
       
        #region 生成缩略图
        /// <summary> 
        /// 生成缩略图 
        /// </summary> 
        /// <param name="originalImagePath">源图路径（物理路径）</param> 
        /// <param name="thumbnailPath">缩略图路径（物理路径）</param> 
        /// <param name="width">缩略图宽度</param> 
        /// <param name="height">缩略图高度</param> 
        /// <param name="mode">生成缩略图的方式</param> 
        public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)
        {
            Image originalImage = Image.FromFile(originalImagePath);
            int towidth = width;
            int toheight = height;
            int x = 0;
            int y = 0;
            int ow = originalImage.Width;
            int oh = originalImage.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 = originalImage.Height * width / originalImage.Width;
                    break;
                case "H"://指定高，宽按比例 
                    towidth = originalImage.Width * height / originalImage.Height;
                    break;
                case "Cut"://指定高宽裁减（不变形） 
                    if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
                    {
                        oh = originalImage.Height;
                        ow = originalImage.Height * towidth / toheight;
                        y = 0;
                        x = (originalImage.Width - ow) / 2;
                    }
                    else
                    {
                        ow = originalImage.Width;
                        oh = originalImage.Width * height / towidth;
                        x = 0;
                        y = (originalImage.Height - oh) / 2;
                    }
                    break;
                default:
                    break;
            }
            //新建一个bmp图片 
            Image bitmap = new System.Drawing.Bitmap(towidth, toheight);
            //新建一个画板 
            Graphics g = System.Drawing.Graphics.FromImage(bitmap);
            //设置高质量插值法 
            g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
            //设置高质量,低速度呈现平滑程度 
            g.SmoothingMode = System.Drawing.Drawing2D.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(originalImage, new Rectangle(0, 0, towidth, toheight),
            new Rectangle(x, y, ow, oh),
            GraphicsUnit.Pixel);
            try
            {
                //以jpg格式保存缩略图 
                bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
            }
            catch (System.Exception e)
            {
                throw e;
            }
            finally
            {
                originalImage.Dispose();
                bitmap.Dispose();
                g.Dispose();
            }
        }

        public static Image MakeThumbnail(Image originalImage, int width, int height, string mode)
        {

            int towidth = width;
            int toheight = height;
            int x = 0;
            int y = 0;
            int ow = originalImage.Width;
            int oh = originalImage.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 = originalImage.Height * width / originalImage.Width;
                    break;
                case "H"://指定高，宽按比例 
                    towidth = originalImage.Width * height / originalImage.Height;
                    break;
                case "Cut"://指定高宽裁减（不变形） 
                    if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
                    {
                        oh = originalImage.Height;
                        ow = originalImage.Height * towidth / toheight;
                        y = 0;
                        x = (originalImage.Width - ow) / 2;
                    }
                    else
                    {
                        ow = originalImage.Width;
                        oh = originalImage.Width * height / towidth;
                        x = 0;
                        y = (originalImage.Height - oh) / 2;
                    }
                    break;
                default:
                    break;
            }
            //新建一个bmp图片 
            Image bitmap = new System.Drawing.Bitmap(towidth, toheight);
            //新建一个画板 
            Graphics g = System.Drawing.Graphics.FromImage(bitmap);
            //设置高质量插值法 
            g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
            //设置高质量,低速度呈现平滑程度 
            g.SmoothingMode = System.Drawing.Drawing2D.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(originalImage, new Rectangle(0, 0, towidth, toheight),
            new Rectangle(x, y, ow, oh),
            GraphicsUnit.Pixel);
            //try
            //{
            //    //以jpg格式保存缩略图 
            //    bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
            //}
            //catch (System.Exception e)
            //{
            //    throw e;
            //}
            //finally
            //{
            //    originalImage.Dispose();
            //    bitmap.Dispose();
            //    g.Dispose();
            //}

            g.Dispose();
            return bitmap;
        } 
        #endregion





    }
}