自动重命名图片,并将地址保存到数据库

//上传
        String path = Server.MapPath("~/UpFile/");// +DateTime.Now.ToShortDateString();
        if (!Directory.Exists(path))
        {
            //在Upload目录下创建了一个文件夹
        Directory.CreateDirectory(path);
        }        String filepath = this.FileUpload1.PostedFile.FileName;
        String myextend = System.IO.Path.GetExtension(filepath);
        Maticsoft.Model.TB_News Tad = new Maticsoft.Model.TB_News();
        Random ran = new Random(DateTime.Now.Millisecond);
        //生成随机的文件名
        String newfilename = DateTime.Now.ToString("yyyyMMddhhmmss") + ran.Next(9999) + myextend;
        String newfilename1 = DateTime.Now.ToString("yyyyMMddhhmmss") + ran.Next(9999) +"shuiyin"+ myextend;
        //判断文件是否存在
        if (filepath.ToString() != "")
        {            sting n_Image = "UpFile/" + newfilename1;
                       if (!String.IsNullOrEmpty(filepath))
            {
                //判断文件大小
                int length = int.Parse(ConfigurationManager.AppSettings["length"]);
                if (this.FileUpload1.PostedFile.ContentLength > length)
                {
                    Response.Write("<script>alert('文件大小超出" + length / 1024 + "k,不允许上传');history.back();</script>");
                    Response.End();
                }
                else
                {
                    //判断文件类型
                    String[] extend = ConfigurationManager.AppSettings["extend"].Split('|');
                    //上传的文件类型
                    String myextend1 = System.IO.Path.GetExtension(filepath);
                    bool flag = true;
                    foreach (String var in extend)
                    {
                        if (var == myextend1)
                        {
                            flag = false;
                            break;
                        }
                    }                    if (flag)//为真不允许的文件类型
                    {
                        Response.Write("<script>alert('文件文件类型不匹配,只允许的类型有" + String.Join("|", extend) + "');history.back();</script>");
                        Response.End();                    }                    //保存文件
                  this.FileUpload1.PostedFile.SaveAs(path + "\\" + newfilename);
                             }

    public String Up_Img()
    {
        string path = string.Empty;
        string fullfilename = this.FileUpload1.PostedFile.FileName;
        if (fullfilename.Length > 2)
        {
            string type1 = fullfilename.Substring(fullfilename.LastIndexOf("."));
            string dt = DateTime.Now.ToString().Trim().Replace("-", "").Replace(":", "").Replace(" ", "");
            string filename = dt.ToString() + type1.ToString();
            string lujing = Server.MapPath("..\\") + "..\\Upload\\Images\\" + filename;
            FileUpload1.PostedFile.SaveAs(lujing);
            path = "Upload\\Images\\" + filename;
        }
        else
        {
            path = "Upload\\Images\\nopic.bmp"; //没有选择图片的情况下录入的图片地址。
        }
        return path;
    }
插入数据库很简单的吧。上面的方法是返回个路径，insert进去就行了。

为了防止保存到数据库中的图片名称重复
通常会这样做：
获取当前时间的毫秒数   再接上一个随机数做为图片的名称
下面是主要代码
//生成唯一标识的文件名
string fileName = DateTime.Now.Ticks.ToString() + new Random().Next();
//获取扩展名   例如  .jpg
string format = this.FileUpload_Image.FileName.Substring(this.FileUpload_Image.FileName.LastIndexOf('.'));
//得到图片名称
string name=fileName+format;
//将图片保存到uploads文件夹下           上传图片
this.FileUpload_Image.SaveAs(Server.MapPath("uploads/" + name));  //uploads事先创建好接下来只需把图片名称保存到数据库就可以了

哦对了我上面的那个方法，如果你一个界面上有好几个图片来同时上传的话，最好能用线程sleep个几十毫秒，要不可能会因为速度太快而少上传图片。不过如果只有一张的话还是没有事情的。

Random rand = new Random();
string num = rand.Next(100, 1000).ToString();
string name = DateTime.Now.ToFileTime().ToString();string filename = url +name
是不是这样的啊

能给一段代码演示下线程sleep的用法吗？谢谢

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default3.aspx.cs" Inherits="Default3" %><!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>
    <form id="form1" runat="server">        <asp:FileUpload ID="FileUpload1" runat="server"  />

        <asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="上传" />

    <asp:SqlDataSource ID="SqlDataSource1" runat="server"
        ConnectionString="<%$ ConnectionStrings:extentionConnectionString %>"
        InsertCommand="INSERT INTO [TB_img] ([img]) VALUES (@img)" >

      <InsertParameters>
      <asp:Parameter Name="img" Type="String"/>
      </InsertParameters>
    </asp:SqlDataSource>
    </form>
</body>
</html>

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.IO;public partial class Default3 : System.Web.UI.Page
{

    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
         string myPath = imgPath();
         if (!(myPath == ""))
         {
             try
             {
                 SqlDataSource1.InsertParameters["img"].DefaultValue = myPath;
                 SqlDataSource1.Insert();             }             catch
             {
                 Response.Write("上传失败，请重试。");
             }
         }

    }    public String imgPath()
    {
        string name = this.FileUpload1.PostedFile.FileName;
        Random ran = new Random(DateTime.Now.Millisecond);
        string path = string.Empty;        if (this.FileUpload1.HasFile)
        {
            if (this.FileUpload1.FileBytes.Count() < 1024000)
            {                //string type = name.Substring(name.LastIndexOf(".")).ToLower(); 学习了一下三楼获得扩展名的方法，很好用
                string type = System.IO.Path.GetExtension(name).ToLower();
                string[] allowedType = { ".gif", ".jpg", ".bmp", ".png" };
                bool checkTpye=false;
                for (int i = 0; i < allowedType.Length; i++)
                {
                    if(allowedType[i] == type)
                    {
                       checkTpye=true;
                    }

                }                    if (checkTpye)
                    {
                        try
                        {
                            string dt = DateTime.Now.ToString("yyyyMMddhhmmss").Trim();
                            string newName = dt + ran.Next(9999) + type;
                            path = "Upload\\Images\\" + newName;
                            string pathRoot = Server.MapPath("~/Upload/Images/");                            if (!Directory.Exists(pathRoot))
                            {
                                Directory.CreateDirectory(pathRoot);
                            }                            this.FileUpload1.PostedFile.SaveAs(pathRoot + newName);
                            Response.Write("上传成功");
                        }                        catch
                        {
                            Response.Write("上传失败，请重试。");
                        }
                    }
                    else
                    {
                        Response.Write("不是允许的文件类型");
                    }

            }
            else
            {
                Response.Write("超过大小限制");
            }        }        else
        {
            path = "Upload\\Images\\noPic.jpg";
            Response.Write("你没有上传图片，系统将使用默认图片");
        }        return path;
    }

    }

如果要配置全局的上传文件大小，可在web.config里
<system.web>
<httpRuntime maxRequestLength="250000"/>
</system.web>

5 楼 jianlanzq，如果你一个界面上有好几个图片来同时上传的话，怎么用线程sleep个几十毫秒，希望能给个演示，谢谢

用sleep太影响效率了，你看以下代码，如果一次上传的图多，人为使其延迟的时间都会很久，还要加上上传时间，用户会以为死机了using System.Threading;public partial class Default3 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        string dt =DateTime.Now.ToString()+":"+ DateTime.Now.Millisecond.ToString();

        Response.Write(dt);
        Thread.Sleep(10000);
       dt = DateTime.Now.ToString() + ":" + DateTime.Now.Millisecond.ToString();        Response.Write("<br/>"+dt);
    }
}

最好用if (filepath.ToString() != "") 断定文件是否存在，然后重新随机命名。

调试易

自动重命名图片,并将地址保存到数据库

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