C# ASP.NET 文件上传和下载

小灰灰 2022-04-01 12:12 272阅读 0赞

可以实现文件的上传，下载，文件重命名等管理。（如果需要源码文件，可直接和博主联系）

**上传限制： **

文件夹容量为1000000M

允许上传类型为：

![20181230202808591.png][]

管理文件：

下载和删除，以及重命名，并且显示已用空间。

<%@ 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 id="Head1" runat="server">
         <title>资源管理</title>
        <style type="text/css">
        /*给body、input和select元素同时应用css*/
        body,input,select
        {
         font-family: "宋体";
         font-size: 10pt;
         font-weight: normal;
         color: #000000;
    } 
        </style>
    </head>
    <body>
        <form id="form1" runat="server">
            <div>
            <table align="center" >
                
                <asp:DropDownList ID="ddl_FunctionList" runat="server" AutoPostBack="True" OnSelectedIndexChanged="ddl_FunctionList_SelectedIndexChanged">
                    <asp:ListItem Value="-1">选择功能</asp:ListItem>
                    <asp:ListItem Value="0">上传限制</asp:ListItem>
                    <asp:ListItem Value="1">上传文件</asp:ListItem>
                    <asp:ListItem Value="2">管理文件</asp:ListItem>
                </asp:DropDownList>
                 
                <asp:Label ID="lab_FolderInfo" runat="server"></asp:Label><br />
                <br />
                <asp:MultiView ID="mvFolder" runat="server" >
                    
                    <asp:View ID="view_Configure" runat="server">
                        允许上传文件的类型：
                        <asp:BulletedList ID="bl_FileTypeLimit" runat="server">
                        </asp:BulletedList>
                        允许上传单个文件的大小：
                        <asp:Label ID="lab_FileSizeLimit" runat="server" Text=""></asp:Label>
                    </asp:View>
                    
                    <asp:View ID="view_Upload" runat="server">
                        <asp:FileUpload ID="FileUpload" runat="server" Width="400px" />
                        <br />
                        <asp:Button ID="btn_Upload" runat="server" Text="上传文件" OnClick="btn_Upload_Click" />
                    </asp:View>
                    
                    <asp:View ID="view_Manage" runat="server">
                        <table cellpadding="5" cellspacing="0" border="0" align="center">
                            <tr>
                                <td>
                                    
                                    <asp:ListBox ID="lb_FileList" runat="server" AutoPostBack="True" Width="300px" Height="300px"
                                        OnSelectedIndexChanged="lb_FileList_SelectedIndexChanged"></asp:ListBox>
                                </td>
                                <td valign="top">
                                    <asp:Label ID="lab_FileDescription" runat="server" Text=""></asp:Label>
                                </td>
                            </tr>
                        </table>
                           <table align="center" >
                        <asp:Button ID="btn_Download" runat="server" Text="下载文件" align="center" OnClick="btn_Download_Click" />
                        
                        <asp:Button ID="btn_Delete" runat="server" Text="删除文件" 
                            OnClick="btn_Delete_Click" /><br />
                        <asp:TextBox ID="tb_FileNewName" runat="server" Width="300px"></asp:TextBox>
                        <asp:Button ID="btn_Rename" runat="server" Text="对文件重命名" OnClick="btn_Rename_Click" /> 
                    </asp:View>
                </asp:MultiView>
                 </table>
          </table>  </div>
        </form>
    </body>
    </html>

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)
        {
            //防止PostBack后列表信息重复添加
            if (!IsPostBack)
            {
                //初始化文件夹信息
                InitFolderInfo();
                //初始化上传限制信息
                InitUploadLimit();
                //初始化文件列表
                InitFileList();
            }
        }
        protected void ddl_FunctionList_SelectedIndexChanged(object sender, EventArgs e)
        {
            //根据下拉框所选调用合适的页面
            mvFolder.ActiveViewIndex = Convert.ToInt16(ddl_FunctionList.SelectedValue);
        }
        protected void btn_Upload_Click(object sender, EventArgs e)
        {
            //判断用户是否选择了文件
            if (FileUpload.HasFile)
            {
                //调用自定义方法判断文件类型是否符合要求
                if (IsAllowableFileType())
                {
                    //调用自定义方法判断文件大小是否符合要求
                    if (IsAllowableFileSize())
                    {
                        //从config中读取文件上传路径
                        string strFileUploadPath = ConfigurationManager.AppSettings["FileUploadPath"].ToString();
                        //从UploadFile中读取文件名
                        string strFileName = FileUpload.FileName;
                        //组合成物理路径
                        string strFilePhysicalPath = Server.MapPath(strFileUploadPath + strFileName);
                        //保存文件
                        FileUpload.SaveAs(strFilePhysicalPath);
                        //更新文件列表框控件
                        lb_FileList.Items.Add(strFileName);
                        //更新文件夹信息
                        InitFolderInfo();
                        //调用自定义方法显示提示
                        ShowMessageBox("文件成功上传");
                    }
                    else
                    {
                        //调用自定义方法显示提示
                        ShowMessageBox("文件大小不符合要求，请参看上传限制");
                    }
                }
                else
                {
                    //调用自定义方法显示提示
                    ShowMessageBox("文件类型不符合要求，请参看上传限制");
                }
            }
            else
            {
                //调用自定义方法显示提示
                ShowMessageBox("请选择一个文件");
            }
        }
        protected void btn_Download_Click(object sender, EventArgs e)
        {
    
            if (lb_FileList.GetSelectedIndices().Length > 0)
            {
    
    
    
    
                //从config中读取文件上传路径
                string strFileUploadPath = ConfigurationManager.AppSettings["FileUploadPath"].ToString();
                //从列表框控件中读取选择的文件名
                string strFileName = lb_FileList.SelectedValue;
                //组合成物理路径
                string strFilePhysicalPath = Server.MapPath(strFileUploadPath + strFileName);
                //清空输出流
                Response.Clear();
                //在HTTP头中加入文件名信息
                Response.AddHeader("Content-Disposition", "attachment;FileName=" + HttpUtility.UrlEncode(strFileName, System.Text.Encoding.UTF8));
                //定义输出流MIME类型为
                Response.ContentType = "application/octet-stream";
                //从磁盘读取文件流
                System.IO.FileStream fs = System.IO.File.OpenRead(strFilePhysicalPath);
                //定义缓冲区大小
                byte[] buffer = new byte[102400];
                //第一次读取
                int i = fs.Read(buffer, 0, buffer.Length);
                //如果读取的字节大于0，则使用BinaryWrite()不断向客户端输出文件流
                while (i > 0)
                {
                    Response.BinaryWrite(buffer);
                    i = fs.Read(buffer, 0, buffer.Length);
                }
                //关闭磁盘文件流
                fs.Close();
                //关闭输出流
                Response.End();
            }
    
    
    
            else
            {
    
                ShowMessageBox("请选择文件");
    
            }
        }
        protected void btn_Delete_Click(object sender, EventArgs e)
        {
    
            if (lb_FileList.GetSelectedIndices().Length > 0)
            {
    
               
    
                //从config中读取文件上传路径
                string strFileUploadPath = ConfigurationManager.AppSettings["FileUploadPath"].ToString();
                //从列表框控件中读取选择的文件名
                string strFileName = lb_FileList.SelectedValue;
                //组合成物理路径
                string strFilePhysicalPath = Server.MapPath(strFileUploadPath + strFileName);
                //删除文件
                System.IO.File.Delete(strFilePhysicalPath);
                //更新文件列表框控件
                lb_FileList.Items.Remove(lb_FileList.Items.FindByText(strFileName));
                //更新文件夹信息
                InitFolderInfo();
                //更新文件描述信息
                tb_FileNewName.Text = "";
                //更新重命名文本框
                lab_FileDescription.Text = "";
                //调用自定义方法显示提示
                ShowMessageBox("文件成功删除");
    
            }
            else
            {
                ShowMessageBox("请选择文件");
            }
        }
        protected void btn_Rename_Click(object sender, EventArgs e)
        {
    
    
            if (lb_FileList.GetSelectedIndices().Length > 0)
            {
    
    
                //从config中读取文件上传路径
                string strFileUploadPath = ConfigurationManager.AppSettings["FileUploadPath"].ToString();
                //从列表框控件中读取选择的文件名
                string strFileName = lb_FileList.SelectedValue;
                //从重命名文本框中读取新文件名
                string strFileNewName = tb_FileNewName.Text;
                //组合成物理路径
                string strFilePhysicalPath = Server.MapPath(strFileUploadPath + strFileName);
                //组合成物理路径
                string strFileNewPhysicalPath = Server.MapPath(strFileUploadPath + strFileNewName);
                //文件重命名
                System.IO.File.Move(strFilePhysicalPath, strFileNewPhysicalPath);
                //找到文件列表框控件中的匹配项
                ListItem li = lb_FileList.Items.FindByText(strFileName);
                //修改文字
                li.Text = strFileNewName;
                //修改值
                li.Value = strFileNewName;
                //调用自定义方法显示提示
                ShowMessageBox("文件成功重命名");
            }
            else
            {
    
    
                ShowMessageBox("请选择文件");
            }
    
    
    
    
        }
        protected void lb_FileList_SelectedIndexChanged(object sender, EventArgs e)
        {
            //从config中读取文件上传路径
            string strFileUploadPath = ConfigurationManager.AppSettings["FileUploadPath"].ToString();
            //从列表框控件中读取选择的文件名
            string strFileName = lb_FileList.SelectedValue;
            //组合成物理路径
            string strFilePhysicalPath = Server.MapPath(strFileUploadPath + strFileName);
            //根据物理路径实例化文件信息类
            FileInfo fi = new FileInfo(strFilePhysicalPath);
            //获得文件大小和创建时间并赋值给标签
            lab_FileDescription.Text = string.Format("文件大小：{0} 字节<br><br>上传时间：{1}<br>", fi.Length, fi.CreationTime);
            //把文件名赋值给重命名文本框
            tb_FileNewName.Text = strFileName;
        }
        private void InitFolderInfo()
        {
            //从config中读取文件上传路径
            string strFileUploadPath = ConfigurationManager.AppSettings["FileUploadPath"].ToString();
            //判断上传文件夹是否存在
            if (!Directory.Exists(Server.MapPath(strFileUploadPath)))
                Directory.CreateDirectory(Server.MapPath(strFileUploadPath));
            //组合成物理路径
            string strFilePath = Server.MapPath(strFileUploadPath);
            //从config中读取文件夹容量限制
            double iFolderSizeLimit = Convert.ToInt32(ConfigurationManager.AppSettings["FolderSizeLimit"]);
            //声明表示文件夹已用空间的变量并赋初始值
            double iFolderCurrentSize = 0;
            //获取文件夹中所有文件
            FileInfo[] arrFiles = new DirectoryInfo(strFilePath).GetFiles();
            //累加文件大小获得已用空间值
            foreach (FileInfo fi in arrFiles)
                iFolderCurrentSize += Convert.ToInt32(fi.Length / 1024);
            //把文件夹容量和已用空间信息赋值给标签
            lab_FolderInfo.Text = string.Format("文件夹容量限制：{0} M 已用空间：{1:f2} M", iFolderSizeLimit / 1024, iFolderCurrentSize / 1024);
        }
        private void InitUploadLimit()
        {
            //从config中读取上传文件类型限制并根据逗号分割成字符串数组
            string[] arrFileTypeLimit = ConfigurationManager.AppSettings["FileTypeLimit"].ToString().Split(',');
            //从config中读取上传文件大小限制
            double iFileSizeLimit = Convert.ToInt32(ConfigurationManager.AppSettings["FileSizeLimit"]);
            //遍历字符串数组把所有项加入项目编号控件
            for (int i = 0; i < arrFileTypeLimit.Length; i++)
                bl_FileTypeLimit.Items.Add(arrFileTypeLimit[i].ToString());
            //把文件大小限制赋值给标签
            lab_FileSizeLimit.Text = string.Format("{0:f2} M", iFileSizeLimit / 1024);
        }
        private void InitFileList()
        {
            //从config中读取文件上传路径
            string strFileUploadPath = ConfigurationManager.AppSettings["FileUploadPath"].ToString();
            //组合成物理路径
            string strFilePath = Server.MapPath(strFileUploadPath);
            //读取文件夹下所有文件
            FileInfo[] arrFiles = new DirectoryInfo(strFilePath).GetFiles();
            //把文件名逐一添加到列表框控件控件
            foreach (FileInfo fi in arrFiles)
                lb_FileList.Items.Add(fi.Name);
        }
        private bool IsAllowableFileSize()
        {
            //从config中读取上传文件大小限制
            double iFileSizeLimit = Convert.ToInt32(ConfigurationManager.AppSettings["FileSizeLimit"]) * 1024;
            //文件大小是否超出了大小限制？
            if (iFileSizeLimit > FileUpload.PostedFile.ContentLength)
                return true;
            else
                return false;
        }
        private bool IsAllowableFileType()
        {
            //从config中读取上传文件类型限制
            string strFileTypeLimit = ConfigurationManager.AppSettings["FileTypeLimit"].ToString();
            //当前文件扩展名是否能在这个字符串中找到？
            if (strFileTypeLimit.IndexOf(Path.GetExtension(FileUpload.FileName).ToLower()) > -1)
                return true;
            else
                return false;
        }
        private void ShowMessageBox(string strMessaage)
        {
            ClientScript.RegisterStartupScript(this.GetType(), "", string.Format("<script>alert('{0}')</script>", strMessaage));
        }
    }

[20181230202808591.png]: /images/20220401/b9e69cdcc03d4ceb8cc43a23312d5ec0.png