[C#] FileUpload 上傳檔案_過濾檔案及解析度

using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

namespace fileupload_test

{

   public partial class WebForm1 : System.Web.UI.Page

   {

       protected void Page_Load(object sender, EventArgs e)

       {

       }

       protected void Button1_Click(object sender, EventArgs e)

       {

           if (FU1.HasFile == false) return;

           // FU1.FileName 只有 "檔案名稱.附檔名"，並沒有 Client 端的完整理路徑

           string filename = FU1.FileName;

           string extension = Path.GetExtension(filename).ToLowerInvariant();

           // 判斷是否為允許上傳的檔案附檔名

           List<string> allowedExtextsion = new List<string> { ".jpg", ".bmp", ".png" };

           if (allowedExtextsion.IndexOf(extension) == -1)

           {

               lblMessage.Text = "不允許該檔案上傳";

               return;

           }

           // 檢查 Server 上該資料夾是否存在，不存在就自動建立

           string serverDir = @"D:\FileUploadDemo";

           if (Directory.Exists(serverDir) == false) Directory.CreateDirectory(serverDir);

           //設定路徑

           string serverFilePath = Path.Combine(serverDir, filename);

           string fileNameOnly = Path.GetFileNameWithoutExtension(filename);

           //判斷解析度寬度小於140 px

           System.Drawing.Image myPic = System.Drawing.Image.FromFile(serverFilePath);

           if (myPic.Width < 140)

           {

               lblMessage.Text = "上傳失敗, 解析度寬度小於140 px!";

               myPic.Dispose(); //最後將物件釋放

               System.IO.File.Delete(serverFilePath); // 將檔案刪除

           }

           else

           {

               // 判斷 Server 上檔案名稱是否有重覆情況，有的話必須進行更名

               // 使用 Path.Combine 來集合路徑的優點

               //  以前發生過儲存 Table 內的是 \\ServerName\Dir（最後面沒有 \ 符號），

               //  直接跟 FileName 來進行結合，會變成 \\ServerName\DirFileName 的情況，

               //  資料夾路徑的最後面有沒有 \ 符號變成還需要判斷，但用 Path.Combine 來結合的話，

               //  資料夾路徑沒有 \ 符號，會自動補上，有的話，就直接結合

               int fileCount = 1;

               while (File.Exists(serverFilePath))

               {

                   // 重覆檔案的命名規則為 檔名_1、檔名_2 以此類推

                   filename = string.Concat(fileNameOnly, "_", fileCount, extension);

                   serverFilePath = Path.Combine(serverDir, filename);

                   fileCount++;

               }

               // 把檔案傳入指定的 Server 內路徑

               try

               {

                   FU1.SaveAs(serverFilePath);

                   lblMessage.Text = "上傳成功, 檔名為: " + filename + "圖片長寬為: " + myPic.Width + " × " + myPic.Height;

               }

               catch (Exception ex)

               {

                   lblMessage.Text = ex.Message;

               }

           }

       }

   }

}