服务器之家

服务器之家 > 正文

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：2019-12-21 13:49     来源/作者：lijiao

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：

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
<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：

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
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：

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
<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：

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
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：

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
<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：

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
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)

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
<%@ 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()"

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
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：

?
1
2
3
4
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）

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
<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：

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
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;
  }
 }
}
是不是内容很精彩，喜欢的朋友就收藏起来吧，以后在遇到ASP.NET文件上传问题的时候能够有所帮助。

 

标签：
asp.net 文件上传 

相关文章

热门资讯

玄元剑仙肉身有什么用 玄元剑仙肉身境界等级划分
玄元剑仙肉身有什么用 玄元剑仙肉身境界等级划分 2019-06-21
男生常说24816是什么意思？女生说13579是什么意思？
男生常说24816是什么意思？女生说13579是什么意思？ 2019-09-17
配置IIS网站web服务器的安全策略配置解决方案
配置IIS网站web服务器的安全策略配置解决方案 2019-05-23
华为nova5pro和p30pro哪个好 华为nova5pro和华为p30pro对比详情
华为nova5pro和p30pro哪个好 华为nova5pro和华为p30pro对比详情 2019-06-22
Nginx服务器究竟是怎么执行PHP项目
Nginx服务器究竟是怎么执行PHP项目 2019-05-24
返回顶部