using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;

namespace ImageProcess
{
??? /// <summary>
??? /// ImageThumbnail 的摘要說明
??? /// </summary>
??? public class ImageThumbnail
??? {

??????? public ImageThumbnail()
??????? {
??????????? //
??????????? // TODO: 在此處添加構造函數邏輯
??????????? //
??????? }

?

??????? /// <summary>
??????? /// 生成縮略圖
??????? /// </summary>
??????? /// <param name="originalImagePath">源圖路徑（物理路徑）</param>
??????? /// <param name="thumbnailPath">縮略圖路徑（物理路徑）</param>
??????? /// <param name="width">縮略圖寬度</param>
??????? /// <param name="height">縮略圖高度</param>
??????? /// <param name="mode">生成縮略圖的方式</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"://指定高寬縮放（可能變形）???????????????
??????????????????? break;
??????????????? case "W"://指定寬，高按比例???????????????????
??????????????????? toheight = originalImage.Height * width / originalImage.Width;
??????????????????? break;
??????????????? case "H"://指定高，寬按比例
??????????????????? towidth = originalImage.Width * height / originalImage.Height;
??????????????????? break;
??????????????? case "Cut"://指定高寬裁減（不變形）???????????????
??????????????????? 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;
??????????? }

??????????? //新建一個bmp圖片
??????????? Image bitmap = new System.Drawing.Bitmap(towidth, toheight);

??????????? //新建一個畫板
??????????? Graphics g = System.Drawing.Graphics.FromImage(bitmap);

??????????? //設置高質量插值法
??????????? g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

??????????? //設置高質量,低速度呈現平滑程度
??????????? g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

??????????? //清空畫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繪制原圖片的指定部分
??????????? g.DrawImage(originalImage, new Rectangle(0, 0, towidth, toheight),
??????????????? new Rectangle(x, y, ow, oh),
??????????????? GraphicsUnit.Pixel);

??????????? try
??????????? {
??????????????? //以jpg格式保存縮略圖
??????????????? bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
??????????? }
??????????? catch (System.Exception e)
??????????? {
??????????????? throw e;
??????????? }
??????????? finally
??????????? {
??????????????? originalImage.Dispose();
??????????????? bitmap.Dispose();
??????????????? g.Dispose();
??????????? }
??????? }

??? }
}

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