方法類：
代碼如下:
upFileClass.cs

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

/// <summary>
/// upFileClass 的摘要說明
/// </summary>
public class upFileClass
{
    public upFileClass()
    {
        //
        // 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)
    {
        System.Drawing.Image originalImage = System.Drawing.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;