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

2024-07-10 13:29:22

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这篇文章主要介绍了asp.net文件上传解决方案，包括：图片上传、单文件上传、多文件上传、检查文件类型等案例，需要的朋友可以参考下

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;

}

}

}