using System;
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using System.Collections.Generic;
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using System.Drawing;
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using System.Linq;
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using System.Text;
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namespace TProduct.Common
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{
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public class ImageHelper
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{
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#region 生成缩略图
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/// <summary>
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/// 生成缩略图
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/// </summary>
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/// <param name="originalImagePath">源图路径（物理路径）</param>
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/// <param name="thumbnailPath">缩略图路径（物理路径）</param>
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/// <param name="width">缩略图宽度</param>
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/// <param name="height">缩略图高度</param>
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/// <param name="mode">生成缩略图的方式</param>
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public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)
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{
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Image originalImage = Image.FromFile(originalImagePath);
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int towidth = width;
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int toheight = height;
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int x = 0;
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int y = 0;
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int ow = originalImage.Width;
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int oh = originalImage.Height;
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switch (mode)
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{
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case "HW"://指定高宽缩放（可能变形）
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break;
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case "W"://指定宽，高按比例
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toheight = originalImage.Height * width / originalImage.Width;
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break;
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case "H"://指定高，宽按比例
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towidth = originalImage.Width * height / originalImage.Height;
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break;
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case "Cut"://指定高宽裁减（不变形）
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if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
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{
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oh = originalImage.Height;
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ow = originalImage.Height * towidth / toheight;
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y = 0;
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x = (originalImage.Width - ow) / 2;
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}
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else
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{
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ow = originalImage.Width;
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oh = originalImage.Width * height / towidth;
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x = 0;
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y = (originalImage.Height - oh) / 2;
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}
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break;
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default:
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break;
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}
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//新建一个bmp图片
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Image bitmap = new System.Drawing.Bitmap(towidth, toheight);
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//新建一个画板
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Graphics g = System.Drawing.Graphics.FromImage(bitmap);
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//设置高质量插值法
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g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
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//设置高质量,低速度呈现平滑程度
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g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
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//清空画布并以透明背景色填充
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g.Clear(Color.Transparent);
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//在指定位置并且按指定大小绘制原图片的指定部分
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g.DrawImage(originalImage, new Rectangle(0, 0, towidth, toheight),
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new Rectangle(x, y, ow, oh),
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GraphicsUnit.Pixel);
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try
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{
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//以jpg格式保存缩略图
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bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
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}
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catch (System.Exception e)
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{
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throw e;
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}
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finally
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{
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originalImage.Dispose();
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bitmap.Dispose();
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g.Dispose();
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}
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}
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public static Image MakeThumbnail(Image originalImage, int width, int height, string mode)
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{
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int towidth = width;
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int toheight = height;
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int x = 0;
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int y = 0;
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int ow = originalImage.Width;
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int oh = originalImage.Height;
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switch (mode)
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{
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case "HW"://指定高宽缩放（可能变形）
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break;
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case "W"://指定宽，高按比例
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toheight = originalImage.Height * width / originalImage.Width;
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break;
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case "H"://指定高，宽按比例
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towidth = originalImage.Width * height / originalImage.Height;
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break;
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case "Cut"://指定高宽裁减（不变形）
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if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
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{
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oh = originalImage.Height;
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ow = originalImage.Height * towidth / toheight;
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y = 0;
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x = (originalImage.Width - ow) / 2;
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}
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else
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{
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ow = originalImage.Width;
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oh = originalImage.Width * height / towidth;
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x = 0;
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y = (originalImage.Height - oh) / 2;
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}
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break;
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default:
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break;
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}
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//新建一个bmp图片
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Image bitmap = new System.Drawing.Bitmap(towidth, toheight);
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//新建一个画板
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Graphics g = System.Drawing.Graphics.FromImage(bitmap);
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//设置高质量插值法
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g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
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//设置高质量,低速度呈现平滑程度
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g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
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//清空画布并以透明背景色填充
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g.Clear(Color.Transparent);
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//在指定位置并且按指定大小绘制原图片的指定部分
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g.DrawImage(originalImage, new Rectangle(0, 0, towidth, toheight),
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new Rectangle(x, y, ow, oh),
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GraphicsUnit.Pixel);
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//try
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//{
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// //以jpg格式保存缩略图
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// bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
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//}
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//catch (System.Exception e)
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//{
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// throw e;
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//}
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//finally
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//{
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// originalImage.Dispose();
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// bitmap.Dispose();
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// g.Dispose();
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//}
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g.Dispose();
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return bitmap;
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}
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#endregion
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}
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}
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