文件上傳控件開發練習

效果圖


還有一個Js文件FielUpLoad.js

var i = 1;

function AddFileToList(obj)
{
    
    //添加一行
    var clientID=obj.parentElement.parentElement.parentElement.parentElement.id;
    var newTr = document.getElementById(clientID).insertRow();

    //添加两列

    var newTd0 = newTr.insertCell();

    var newTd1 = newTr.insertCell();

    var newTd2 = newTr.insertCell();

    //设置列内容和属性
    var file = document.createElement("input");
    file.type = "file";
    file.id = file.name = "file" + i;
    file.name = "title";
    newTd0.appendChild(file);

    var btn =  document.createElement("input");
    btn.type = "button";
    btn.id = btn.name = "btn" + i;

    btn.value = "移除";

    btn.onclick = function() 
    { 
    var index=window.event.srcElement.parentElement.parentElement.rowIndex;
    document.getElementById(clientID).deleteRow(index);
    }

  newTd1.appendChild(btn);
 
  i++;
  return false;
}

設計文件FileUpLoad.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Text;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.IO;

namespace FielUpLoad
{
    [ToolboxData("<{0}:FielUpLoad runat=server></{0}:FielUpLoad>")]
    public class FielUpLoad : WebControl, INamingContainer
    {
        屬性定義#region 屬性定義
        private Button btnAddFileToList;//添加文件按鈕
        private Button btnStartUpload;//文件上傳按鈕
        private HtmlInputFile hifFile;//文件瀏覽控件

        [Bindable(true)]
        [Category("Appearance")]
        [DefaultValue(1048576)]
        [Localizable(true)]
        [Description("文件總共最大的長度(單位KB)預設是1024*1024KB")]
        public int TotalMaxFileLength
        {
            set
            {
                EnsureChildControls();
                ViewState["TotalMaxFileLength"] = value;
            }
            get
            {
                EnsureChildControls();
                return ((ViewState["TotalMaxFileLength"] == null) ? 1048576 : (int)ViewState["TotalMaxFileLength"]);
            }

        }

        [Bindable(true)]
        [Category("Appearance")]
        [DefaultValue(1024)]
        [Localizable(true)]
        [Description("單個文件最大的長度(單位KB)預設是1024KB")]
        public int SingleMaxFileLength
        {
            set
            {
                EnsureChildControls();
                ViewState.Add("SingleMaxFileLength", value);
            }
            get
            {
                EnsureChildControls();
                return ((ViewState["SingleMaxFileLength"] == null) ? 1024 : (int)ViewState["SingleMaxFileLength"]);
            }
        }

        [Category("Appearance"), Description("文件要存放的相對路徑如~\\存放在根目錄")]
        public string ServerFilePath
        {
            set
            {
                EnsureChildControls();
                ViewState.Add("ServerFilePath", value);
            }
            get
            {
                EnsureChildControls();
                String s = (String)ViewState["ServerFilePath"];
                return ((s == null) ? "~\\" : s);
            }
        }


        [Bindable(true)]
        [Category("Appearance")]
        [DefaultValue(true)]
        [Localizable(true)]
        [Description("上傳文件名是否保留,還是重新產生")]
        public bool FileNameHold
        {
            set
            {
                EnsureChildControls();
                ViewState.Add("FileNameHold",value);
            }
            get
            {
                EnsureChildControls();
                return ((ViewState["FileNameHold"] == null) ? true : (bool)ViewState["FileNameHold"]);
            }
        }

        #endregion

        顯示消息的函數#region 顯示消息的函數
        /**//// <summary>
        /// 顯示消息的函數
        /// </summary>
        /// <param name="java"></param>
        protected void ShowMessage(string sMessage)
        {
            Page.ClientScript.RegisterStartupScript(this.GetType(), "fsf", "<script language=javascript>alert('" + sMessage + "');</script>");
        }
        #endregion

        創建子控件#region 創建子控件
        /**//// <summary>
        /// 創建子控件
        /// </summary>
        protected override void CreateChildControls()
        {
            Controls.Clear();

            this.ServerFilePath = @"~\";

            hifFile = new HtmlInputFile();
            hifFile.ID = "HtmlInputFilehifFile";

            btnAddFileToList = new Button();
            btnAddFileToList.Text = "添加";
            btnAddFileToList.ID = "btnAddFileToList";
            btnAddFileToList.OnClientClick = "return AddFileToList(this)";


            btnStartUpload = new Button();
            btnStartUpload.Text = "上傳";
            btnStartUpload.ID = "btnStartUpload";
            btnStartUpload.Click += new EventHandler(btnStartUpload_Click);

            this.Controls.Add(hifFile);
            this.Controls.Add(btnAddFileToList);
            this.Controls.Add(btnStartUpload);
            
        }
        #endregion

        控件布局#region 控件布局
        /**//// <summary>
        /// 控件布局
        /// </summary>
        /// <param name="writer"></param>
        protected override void Render(HtmlTextWriter writer)
        {
            EnsureChildControls();//這句好重要啊，我開始沒有這句，控件拖出來就有錯誤
            AddAttributesToRender(writer);
            writer.RenderBeginTag(HtmlTextWriterTag.Table);
            writer.RenderBeginTag(HtmlTextWriterTag.Tr);
            writer.RenderBeginTag(HtmlTextWriterTag.Td);
            hifFile.RenderControl(writer);
            writer.RenderEndTag();  // Td
            writer.RenderBeginTag(HtmlTextWriterTag.Td);
            btnAddFileToList.RenderControl(writer);
            writer.RenderEndTag();  // Td
            writer.RenderBeginTag(HtmlTextWriterTag.Td);
            btnStartUpload.RenderControl(writer);
            writer.RenderEndTag();  // Td
            writer.RenderEndTag();  // Tr

            writer.RenderEndTag();  // Table


        }

        #endregion

        重寫OnPreRender#region 重寫OnPreRender
        protected override void OnPreRender(EventArgs e)
        {
            if (this.Page != null)
            {
                this.Page.ClientScript.RegisterClientScriptResource(this.GetType(), "FielUpLoad.FielUpLoad.js");
            }
            base.OnPreRender(e);
        }

        #endregion

        單擊按鈕上傳文件#region 單擊按鈕上傳文件
        /**//// <summary>
        /// 單擊按鈕上傳文件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnStartUpload_Click(object sender, System.EventArgs e)
        {
            SaveAs();
        }
        #endregion

        文件上傳另存為#region 文件上傳另存為
        /**//// <summary>
        /// 文件上傳另存為
        /// </summary>
        /// <returns>文件存放路徑以及文件名如：C:\Documents and Settings\Administrator\My Documents\Visual Studio 2005\WebSites\WebSite2\ada\+20070302044811.jpg,20070302044811.jpg,</returns>
        public string SaveAs()
        {
            HttpFileCollection files = System.Web.HttpContext.Current.Request.Files;
            string sFileSavePath = GetAbsolutePath(@ServerFilePath);
            string sReturnFileName =sFileSavePath+"+";

            //判斷文件大小是否超出
            if (!IsAllowedLength())
                return "";
            for (int i = 0; i < files.Count; i++)
            {
                if (files[i].FileName.Length > 0)
                {
                    string sFileSavePathName = "";
                    if (FileNameHold)
                        sFileSavePathName = sFileSavePath + System.IO.Path.GetFileName(files[i].FileName);
                    else
                        sFileSavePathName = sFileSavePath + GetUniqueString()+i.ToString()+ System.IO.Path.GetExtension(files[i].FileName);

                    files[i].SaveAs(sFileSavePathName);
                    sReturnFileName =sReturnFileName+ System.IO.Path.GetFileName(sFileSavePathName)+",";
                }
            }

            return sReturnFileName;
        }
        #endregion

        根據相對路徑取得絕對路徑#region 根據相對路徑取得絕對路徑
        /**//// <summary>
        /// 根據相對路徑取得絕對路徑
        /// </summary>
        /// <param name="sFilePath">相對路徑</param>
        /// <returns></returns>
        private string GetAbsolutePath(string sFilePath)
        {
            try
            {
                //取得絕對路徑
                string sAbsolutePath = HttpContext.Current.Request.MapPath(sFilePath);
                //判断路径是否存在,若不存在则创建路径 
                DirectoryInfo upDir = new DirectoryInfo(sAbsolutePath);
                if (!upDir.Exists)
                {
                    upDir.Create();
                }
                //如果路径末尾为\符号，则直接返回路徑
                if (sAbsolutePath.LastIndexOf("\\") != sAbsolutePath.Length)
                    sAbsolutePath += "\\";
                return sAbsolutePath;
            }
            catch
            {
                throw new Exception("由相對路徑取得絕對路徑失敗!");
            }
        }

        #endregion

        获取一个不重复的文件名#region 获取一个不重复的文件名
        /**//// <summary>
        /// 获取一个不重复的文件名
        /// </summary>
        /// <returns>得到的文件名形如：20050922101010</returns>
        private string GetUniqueString()
        {
            return DateTime.Now.ToString("yyyyMMddhhmmss");
        }
        #endregion

        判断上传文件大小是否合乎要求#region 判断上传文件大小是否合乎要求
        /**//// <summary>
        /// 判断上传文件大小是否合乎要求
        /// </summary>
        /// <returns></returns>
        public  bool IsAllowedLength()
        {
            bool bAllowed = true;
            HttpFileCollection files = System.Web.HttpContext.Current.Request.Files;
            double dTotalLength = 0;

            //判斷上传文件的大小超过單個最大值
            for (int i = 0; i < files.Count; i++)
            {
                if (files[i].ContentLength / 1024.0 > SingleMaxFileLength)
                {
                    bAllowed =false;
                    ShowMessage("上傳文件失敗,單個文件超過允許最大值!");
                    break;
                }
                dTotalLength += files[i].ContentLength / 1024.0;
            }

            if (dTotalLength > TotalMaxFileLength)
            {
                bAllowed = false;
                ShowMessage("上傳文件失敗,縂文件超過允許最大值!");
            }
            return bAllowed;
        }
        #endregion

    }
}