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  • 怎么同时上传多张图片并预览图片信息

    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.Collections;

    public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
         
        }

        /// <summary>
        /// 增加按钮
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected void btnAdd_Click(object sender, EventArgs e)
        {
            ArrayList arraylist = new ArrayList();

            if (Session["UPLOAD"] == null)
            {
                //检查是否有文件要上传
                if (this.FileUpload1.HasFile)
                {
                    if (this.FileUpload1.PostedFile.ContentLength > 4096000)
                    {
                        lblResult.Text = "文件不能超过4M!";
                        return;
                    }
                    else
                    {
                        lblResult.Text = "";
                    }

                    //将要上传的文件存入ArrayList和Session中
                    arraylist.Add(this.FileUpload1.PostedFile);
                    Session["UPLOAD"] = arraylist;
                }
                else
                {
                    lblResult.Text = "请选择上传文件!";
                }
            }
            else if (Session["UPLOAD"] != null)
            {
                //检查是否有文件要上传
                if (this.FileUpload1.HasFile)
                {
                    if (this.FileUpload1.PostedFile.ContentLength > 4096000)
                    {
                        lblResult.Text = "文件不能超过4M!";
                        return;
                    }
                    else
                    {
                        lblResult.Text = "";
                    }
                    arraylist = Session["UPLOAD"] as ArrayList;

                    //将要上传的文件存入ArrayList和Session中
                    arraylist.Add(this.FileUpload1.PostedFile);
                    Session["UPLOAD"] = arraylist;
                }
                else
                {
                    lblResult.Text = "请选择上传文件!";
                }
            }

            //绑定DataList
            DataList1.DataSource = Session["UPLOAD"];
            DataList1.DataBind();
        }

        /// <summary>
        /// 上传按钮
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param> n,
        protected void btnUpload_Click(object sender, EventArgs e)
        {
            string strPath = Server.MapPath("~/files/");

            if (Session["UPLOAD"] != null)
            {
                //从ArrayList中取出要上传的文件
                ArrayList list = Session["UPLOAD"] as ArrayList;
                for (int i = 0; i < list.Count; i++)
                {
                    HttpPostedFile PostedFile = list[i] as HttpPostedFile;

                    //将文件上传到指定路径
                    PostedFile.SaveAs(strPath + System.IO.Path.GetFileName(PostedFile.FileName));
                }
                lblResult.Text = "上传成功!";
            }

            //上传后清空上传文件列表
            if (CheckBox1.Checked)
            {
                Session["UPLOAD"] = null;
                DataList1.DataSource = Session["UPLOAD"];
                DataList1.DataBind();
            }
        }
    }

    前台代码:

    <%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" Debug="true"%>

    <!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>无标题页</title>
    </head>
    <body>
    <center>
    <h2>
        &nbsp;</h2>
        <form id="form1" runat="server">
        <div>
            &nbsp;
       
            <asp:Label ID="Label1" runat="server" Style="font-weight: bold; font-size: x-large"
                Text="文件上传操作示例"></asp:Label>
       
        </div>
            <table border="1" style=" 676px; height: 197px">
                <tr>
                    <td colspan="3">
                        <asp:FileUpload ID="FileUpload1" runat="server" Width="404px" Height="29px" /></td>
                </tr>
                <tr>
                    <td colspan="3" rowspan="2">
                        <asp:Label ID="lblResult" runat="server" ForeColor="Red"></asp:Label></td>
                </tr>
                <tr>
                </tr>
                <tr>
                    <td colspan="2" rowspan="1" style=" 2503px; height: 25px;" align="center">
                        <asp:Button ID="btnAdd" runat="server" Text="增 加" OnClick="btnAdd_Click" /></td>
                    <td colspan="1" rowspan="1" align="center" style="height: 25px">
                        &nbsp;<asp:Button ID="btnUpload" runat="server" OnClick="btnUpload_Click" Text="上 传" /></td>
                </tr>
                <tr>
                    <td align="center" colspan="3" rowspan="1">
                        <asp:CheckBox ID="CheckBox1" runat="server" Text="上传后清空上传文件列表" AutoPostBack="True" /></td>
                </tr>
                <tr>
                    <td colspan="3" rowspan="2">
                        <asp:DataList ID="DataList1" runat="server" CellPadding="3" Height="1px" Width="615px" BackColor="White" BorderColor="#E7E7FF" BorderStyle="None" BorderWidth="1px" GridLines="Horizontal">
                            <FooterStyle BackColor="#B5C7DE" ForeColor="#4A3C8C" />
                            <SelectedItemStyle BackColor="#738A9C" Font-Bold="True" ForeColor="#F7F7F7" />
                            <AlternatingItemStyle BackColor="#F7F7F7" />
                            <ItemStyle BackColor="#E7E7FF" ForeColor="#4A3C8C" />
                            <HeaderStyle BackColor="#4A3C8C" Font-Bold="True" ForeColor="#F7F7F7" />
                            <ItemTemplate>
                                &nbsp;
                                <table style=" 419px; height: 54px">
                                    <tr>
                                        <td>
                                            文件名称:</td>
                                        <td style=" 288px">
                                <asp:Label ID="lblName" runat="server" Text='<%# Eval("FileName") %>'></asp:Label></td>
                                    </tr>
                                    <tr>
                                        <td>
                                            文件大小:</td>
                                        <td style=" 288px">
                                            <asp:Label ID="lblLength" runat="server" Text='<%# Eval("ContentLength") %>'></asp:Label></td>
                                    </tr>
                                    <tr>
                                        <td style="height: 20px">
                                            文件类型:</td>
                                        <td style=" 288px; height: 20px;">
                                            <asp:Label ID="lblType" runat="server" Text='<%# Eval("ContentType") %>'></asp:Label></td>
                                    </tr>
                                </table>
                            </ItemTemplate>
                            <HeaderTemplate>
                                上传文件列表
                            </HeaderTemplate>
                        </asp:DataList>&nbsp;</td>
                </tr>
                <tr>
                </tr>
            </table>
        </form>
        </center>
    </body>
    </html>

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  • 原文地址:https://www.cnblogs.com/lushuicongsheng/p/1893499.html
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