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