asp.net檔案上傳解決方案（圖片上傳、單檔案上傳、多檔案上傳、檢查檔案類型）

asp.net檔案上傳解決方案（圖片上傳、單檔案上傳、多檔案上傳、檢查檔案類型）_實用技巧

最後更新：2017-01-19 來源：互聯網

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小編之前也介紹了許多ASP.NET檔案上傳的解決案例，今天來個asp.net檔案上傳大集合。

1 使用標準HTML來進行圖片上傳
前台代碼：

<body>  <form id="form1" runat="server">  <div>   <table>    <tr>     <td colspan="2" style="height: 21px" >      使用標準HTML來進行圖片上傳</td>    </tr>    <tr>     <td style="width: 400px">      <input id="InputFile" style="width: 399px" type="file" runat="server" /></td>     <td style="width: 80px">      <asp:Button ID="UploadButton" runat="server" Text="上傳圖片" OnClick="UploadButton_Click" /></td>    </tr>    <tr>     <td colspan="2" >      <asp:Label ID="Lb_Info" runat="server" ForeColor="Red"></asp:Label></td>        </tr>   </table>   </div>  </form> </body>

後台代碼：

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; public partial class _Default : System.Web.UI.Page {  protected void Page_Load(object sender, EventArgs e)  {  }  protected void UploadButton_Click(object sender, EventArgs e)  {   string uploadName = InputFile.Value;//擷取待上傳圖片的完整路徑，包括檔案名稱   //string uploadName = InputFile.PostedFile.FileName;   string pictureName = "";//上傳後的圖片名，以目前時間為檔案名稱，確保檔案名稱沒有重複   if (InputFile.Value != "")   {    int idx = uploadName.LastIndexOf(".");    string suffix = uploadName.Substring(idx);//獲得上傳的圖片的尾碼名    pictureName = DateTime.Now.Ticks.ToString() + suffix;   }   try   {    if (uploadName != "")    {     string path = Server.MapPath("~/images/");     InputFile.PostedFile.SaveAs(path + pictureName);    }   }   catch (Exception ex)   {    Response.Write(ex);   }  } }

2 單檔案上傳
這是最基本的檔案上傳，在asp.net1.x中沒有這個FileUpload控制項，只有html的上傳控制項，那時候要把html控制項轉化為伺服器控制項，很不好用。其實所有檔案上傳的美麗效果都是從這個FileUpload控制項衍生，第一個例子雖然簡單卻是根本。
前台代碼：

<body>  <form id="form1" runat="server">  <div>   <table style="width: 90%">    <tr>     <td style="width: 159px" colspan=2>      <strong><span style="font-size: 10pt">最簡單的單檔案上傳</span></strong></td>    </tr>    <tr>     <td style="width: 600px">      <asp:FileUpload ID="FileUpload1" runat="server" Width="600px" /></td>     <td align=left>      <asp:Button ID="FileUpload_Button" runat="server" Text="上傳圖片" OnClick="FileUpload_Button_Click" /></td>    </tr>    <tr>     <td colspan=2>      <asp:Label ID="Upload_info" runat="server" ForeColor="Red" Width="767px"></asp:Label></td>    </tr>   </table>   </div>  </form> </body>

後台代碼：

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; public partial class _Default : System.Web.UI.Page {  protected void Page_Load(object sender, EventArgs e)  {  }  protected void FileUpload_Button_Click(object sender, EventArgs e)  {   try   {    if (FileUpload1.PostedFile.FileName == "")    //if (FileUpload1.FileName == "")    //if (!FileUpload1.HasFile)  //擷取一個值，該值指示 System.Web.UI.WebControls.FileUpload 控制項是否包含檔案。包含檔案，則為 true；否則為 false。    {     this.Upload_info.Text = "請選擇上傳檔案！";    }    else    {     string filepath = FileUpload1.PostedFile.FileName; //得到的是檔案的完整路徑,包括檔案名稱，如：C:\Documents and Settings\Administrator\My Documents\My Pictures\20022775_m.jpg     //string filepath = FileUpload1.FileName;    //得到上傳的檔案名稱20022775_m.jpg     string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);//20022775_m.jpg     string serverpath = Server.MapPath("~/images/") + filename;//取得檔案在伺服器上儲存的位置C:\Inetpub\wwwroot\WebSite1\images\20022775_m.jpg     FileUpload1.PostedFile.SaveAs(serverpath);//將上傳的檔案另存新檔     this.Upload_info.Text = "上傳成功！";    }   }   catch (Exception ex)   {    this.Upload_info.Text = "上傳發生錯誤！原因是：" + ex.ToString();   }  } }

3、多檔案上傳
前台代碼：

<body>  <form id="form1" runat="server">  <div>  <table style="width: 343px">    <tr>     <td style="width: 100px">      多檔案上傳</td>     <td style="width: 100px">     </td>    </tr>    <tr>     <td style="width: 100px">      <asp:FileUpload ID="FileUpload1" runat="server" Width="475px" />      </td>     <td style="width: 100px">      </td>    </tr>    <tr>     <td style="width: 100px">      <asp:FileUpload ID="FileUpload2" runat="server" Width="475px" /></td>     <td style="width: 100px">     </td>    </tr>    <tr>     <td style="width: 100px">      <asp:FileUpload ID="FileUpload3" runat="server" Width="475px" /></td>     <td style="width: 100px">     </td>    </tr>    <tr>     <td style="width: 100px">      <asp:Button ID="bt_upload" runat="server" OnClick="bt_upload_Click" Text="一起上傳" />      <asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="448px"></asp:Label></td>     <td style="width: 100px">     </td>    </tr>   </table>  </div>  </form> </body>

後台代碼：

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; public partial class _Default : System.Web.UI.Page {  protected void Page_Load(object sender, EventArgs e)  {  }  protected void bt_upload_Click(object sender, EventArgs e)  {   if (FileUpload1.PostedFile.FileName == "" && FileUpload2.PostedFile.FileName == "" && FileUpload3.PostedFile.FileName == "")   {    this.lb_info.Text = "請選擇檔案！";   }   else   {    HttpFileCollection myfiles = Request.Files;    for (int i = 0; i < myfiles.Count; i++)    {     HttpPostedFile mypost = myfiles[i];     try     {      if (mypost.ContentLength > 0)      {       string filepath = mypost.FileName;//C:\Documents and Settings\Administrator\My Documents\My Pictures\20022775_m.jpg       string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);//20022775_m.jpg       string serverpath = Server.MapPath("~/images/") + filename;//C:\Inetpub\wwwroot\WebSite2\images\20022775_m.jpg       mypost.SaveAs(serverpath);       this.lb_info.Text = "上傳成功！";      }     }     catch (Exception ex)     {      this.lb_info.Text = "上傳發生錯誤！原因：" + ex.Message.ToString();     }    }   }  } }

4、用戶端檢查上傳檔案類型(以上傳圖片為例)

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server">  <title>用戶端檢查上傳檔案類型</title>  <script language="javascript">  function Check_FileType()  {   var str=document.getElementById("FileUpload1").value;   var pos=str.lastIndexOf(".");   var lastname=str.substring(pos,str.length);   if(lastname.toLowerCase()!=".jpg"&&lastname.toLowerCase()!=".gif")   {    alert("您上傳的檔案類型為"+lastname+"，圖片必須為.jpg,.gif類型");    return false;   }   else   {    return true;   }    }  </script> </head> <body>  <form id="form1" runat="server">  <div>   <table>    <tr>     <td colspan="2">      用戶端檢查上傳檔案類型</td>        </tr>    <tr>     <td style="width: 444px">      <asp:FileUpload ID="FileUpload1" runat="server" Width="432px" /></td>     <td style="width: 80px">      <asp:Button ID="bt_upload" runat="server" Text="上傳圖片" OnClick="bt_upload_Click" OnClientClick="return Check_FileType()" /></td>    </tr>    <tr>     <td colspan="2" style="height: 21px">      <asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="515px"></asp:Label></td>        </tr>   </table>   </div>  </form> </body> </html>

注意：點擊上傳時先觸發用戶端事件OnClientClick="return Check_FileType()"

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; public partial class _Default : System.Web.UI.Page {  protected void Page_Load(object sender, EventArgs e)  {  }  protected void bt_upload_Click(object sender, EventArgs e)  {   try   {    if (FileUpload1.PostedFile.FileName == "")    {     this.lb_info.Text = "請選擇檔案！";    }    else    {     string filepath = FileUpload1.PostedFile.FileName;     //if (!IsAllowedExtension(FileUpload1))     //{     // this.lb_info.Text = "上傳檔案格式不正確！";     //}     if (IsAllowedExtension(FileUpload1) == true)     {      string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);      string serverpath = Server.MapPath("~/images/") + filename;      FileUpload1.PostedFile.SaveAs(serverpath);      this.lb_info.Text = "上傳成功！";     }     else     {      this.lb_info.Text = "請上傳圖片！";     }    }   }   catch (Exception ex)   {    this.lb_info.Text = "上傳發生錯誤！原因：" + ex.ToString();   }  }  private static bool IsAllowedExtension(FileUpload upfile)  {   string strOldFilePath = "";   string strExtension="";   string[] arrExtension ={ ".gif", ".jpg", ".bmp", ".png" };   if (upfile.PostedFile.FileName != string.Empty)   {    strOldFilePath = upfile.PostedFile.FileName;//獲得檔案的完整路徑名    strExtension = strOldFilePath.Substring(strOldFilePath.LastIndexOf("."));//獲得檔案的副檔名，如：.jpg    for (int i = 0; i < arrExtension.Length; i++)    {     if (strExtension.Equals(arrExtension[i]))     {      return true;     }    }   }   return false;  } }

注意：若去掉用戶端的指令碼和用戶端事件OnClientClick="return Check_FileType()"，在後台代碼
改為：

if (!IsAllowedExtension(FileUpload1))     {      this.lb_info.Text = "上傳檔案格式不正確！";     }

else if (IsAllowedExtension(FileUpload1) == true)
即變成伺服器端檢查上傳檔案類型。
5、伺服器端檢查上傳檔案的類型（檔案內部真正的格式）

<body>  <form id="form1" runat="server">  <div>   <table>    <tr>     <td colspan="2">      伺服器檢查上傳檔案類型</td>        </tr>    <tr>     <td style="width: 444px">      <asp:FileUpload ID="FileUpload1" runat="server" Width="432px" /></td>     <td style="width: 80px">      <asp:Button ID="bt_upload" runat="server" Text="上傳圖片" OnClick="bt_upload_Click" /></td>    </tr>    <tr>     <td colspan="2" style="height: 21px">      <asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="515px"></asp:Label></td>        </tr>   </table>   </div>  </form> </body>

後台代碼：

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; using System.IO; public partial class _Default : System.Web.UI.Page {  protected void Page_Load(object sender, EventArgs e)  {  }  protected void bt_upload_Click(object sender, EventArgs e)  {   try   {    if (FileUpload1.PostedFile.FileName == "")    {     this.lb_info.Text = "請選擇檔案！";    }    else    {     string filepath = FileUpload1.PostedFile.FileName;     if (IsAllowedExtension(FileUpload1) == true)     {      string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);      string serverpath = Server.MapPath("images/") + filename;      FileUpload1.PostedFile.SaveAs(serverpath);      this.lb_info.Text = "上傳成功！";     }     else     {      this.lb_info.Text = "請上傳圖片";     }    }   }   catch (Exception error)   {    this.lb_info.Text = "上傳發生錯誤！原因：" + error.ToString();   }  }  private static bool IsAllowedExtension(FileUpload upfile)  {   FileStream fs = new FileStream(upfile.PostedFile.FileName, FileMode.Open, FileAccess.Read);   BinaryReader r = new BinaryReader(fs);   string fileclass = "";   byte buffer;   try   {    buffer = r.ReadByte();    fileclass = buffer.ToString();    buffer = r.ReadByte();    fileclass += buffer.ToString();   }   catch   {       }   r.Close();   fs.Close();   if (fileclass == "255216" || fileclass == "7173"||fileclass=="6677"||fileclass=="13780")//說明255216是jpg;7173是gif;6677是BMP,13780是PNG;7790是exe,8297是rar   {    return true;   }   else   {    return false;   }  } }

為大家推薦一個專題，供大家學習：《ASP.NET檔案上傳匯總》

是不是內容很精彩，喜歡的朋友就收藏起來吧，以後在遇到ASP.NET檔案上傳問題的時候能夠有所協助。

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