asp.net文件上传解决方案(图片上传、单文件上传、多文件上传、检查文件类型)

时间:2021-05-28

小编之前也介绍了许多ASP.NET文件上传的解决案例,今天来个asp.net文件上传大集合。

1 使用标准HTML来进行图片上传
前台代码:

<body> <form id="form1" runat="server"> <div> <table> <tr> <td colspan="2" style="height: 21px" > 使用标准HTML来进行图片上传</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="上传图片" 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>


后台代码:

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;//获取待上传图片的完整路径,包括文件名 //string uploadName = InputFile.PostedFile.FileName; string pictureName = "";//上传后的图片名,以当前时间为文件名,确保文件名没有重复 if (InputFile.Value != "") { int idx = uploadName.LastIndexOf("."); string suffix = uploadName.Substring(idx);//获得上传的图片的后缀名 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 单文件上传
这是最基本的文件上传,在asp.net1.x中没有这个FileUpload控件,只有html的上传控件,那时候要把html控件转化为服务器控件, 很不好用。其实所有文件上传的美丽效果都是从这个FileUpload控件衍生,第一个例子虽然简单却是根本。
前台代码:

<body> <form id="form1" runat="server"> <div> <table style="width: 90%"> <tr> <td style="width: 159px" colspan=2> <strong><span style="font-size: 10pt">最简单的单文件上传</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="上传图片" 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>

后台代码:

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) //获取一个值,该值指示 System.Web.UI.WebControls.FileUpload 控件是否包含文件。包含文件,则为 true;否则为 false。 { this.Upload_info.Text = "请选择上传文件!"; } else { string filepath = FileUpload1.PostedFile.FileName; //得到的是文件的完整路径,包括文件名,如:C:\Documents and Settings\Administrator\My Documents\My Pictures\20022775_m.jpg //string filepath = FileUpload1.FileName; //得到上传的文件名20022775_m.jpg string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);//20022775_m.jpg string serverpath = Server.MapPath("~/images/") + filename;//取得文件在服务器上保存的位置C:\Inetpub\wwwroot\WebSite1\images\20022775_m.jpg FileUpload1.PostedFile.SaveAs(serverpath);//将上传的文件另存为 this.Upload_info.Text = "上传成功!"; } } catch (Exception ex) { this.Upload_info.Text = "上传发生错误!原因是:" + ex.ToString(); } } }


3、多文件上传
前台代码:

<body> <form id="form1" runat="server"> <div> <table style="width: 343px"> <tr> <td style="width: 100px"> 多文件上传</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="一起上传" /> <asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="448px"></asp:Label></td> <td style="width: 100px"> </td> </tr> </table> </div> </form> </body>


后台代码:

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 = "请选择文件!"; } 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 = "上传成功!"; } } catch (Exception ex) { this.lb_info.Text = "上传发生错误!原因:" + ex.Message.ToString(); } } } } }

4、客户端检查上传文件类型(以上传图片为例)

<%@ 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>客户端检查上传文件类型</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("您上传的文件类型为"+lastname+",图片必须为.jpg,.gif类型"); return false; } else { return true; } } </script> </head> <body> <form id="form1" runat="server"> <div> <table> <tr> <td colspan="2"> 客户端检查上传文件类型</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="上传图片" 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:点击上传时先触发客户端事件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 = "请选择文件!"; } else { string filepath = FileUpload1.PostedFile.FileName; //if (!IsAllowedExtension(FileUpload1)) //{ // this.lb_info.Text = "上传文件格式不正确!"; //} 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 = "上传成功!"; } else { this.lb_info.Text = "请上传图片!"; } } } catch (Exception ex) { this.lb_info.Text = "上传发生错误!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;//获得文件的完整路径名 strExtension = strOldFilePath.Substring(strOldFilePath.LastIndexOf("."));//获得文件的扩展名,如:.jpg for (int i = 0; i < arrExtension.Length; i++) { if (strExtension.Equals(arrExtension[i])) { return true; } } } return false; } }

注意:若去掉客户端的脚本和客户端事件OnClientClick="return Check_FileType()",在后台代码
改为:

if (!IsAllowedExtension(FileUpload1)) { this.lb_info.Text = "上传文件格式不正确!"; }


else if (IsAllowedExtension(FileUpload1) == true)
即变成服务器端检查上传文件类型。
5、服务器端检查上传文件的类型(文件内部真正的格式)

<body> <form id="form1" runat="server"> <div> <table> <tr> <td colspan="2"> 服务器检查上传文件类型</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="上传图片" 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>

后台代码:

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 = "请选择文件!"; } 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 = "上传成功!"; } else { this.lb_info.Text = "请上传图片"; } } } catch (Exception error) { this.lb_info.Text = "上传发生错误!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")//说明255216是jpg;7173是gif;6677是BMP,13780是PNG;7790是exe,8297是rar { return true; } else { return false; } } }

为大家推荐一个专题,供大家学习:《ASP.NET文件上传汇总》

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