如何用ASP.NET实现图片上传？（80分）

上传(upload)文件的codebehind代码
eKiller 发表于 1/27/2002 11:38:47 AM ASP.NET ←返回版面         [快速返回] 功能：
1。把图片文件(JPG GIF PNG)上传，
2。保存到指定的路径（在web.config中设置路径，以文件的原有格式保存），
3。并自动生成指定宽度的（在web.config中设置宽度）
4。和指定格式的（在web.config中指定缩略图的格式）
5。和原图比例相同的缩略图(根据宽度和原图的宽和高计算所略图的高度)
6。可以判断是否已经存在文件
7。如果不覆盖，则给出错误
8。如果选中"覆盖原图"checkbox，则覆盖原图。
9。可以根据要求，在webform上设置1个以上的file input和相应的checkbox
10。并在文件上传完毕后，显示原图的文件名，尺寸，字节，和
11。缩略图的文件名尺寸。
12。缩略图的文件名格式：原图+"_thumb."+指定格式，如：test.jpg_thumb.gif,以便于管理。--------------------
public void UploadFile(object sender, System.EventArgs e)
        {

                string imgNameOnly, imgNameNoExt, imgExt;
                string imgThumbnail;
                int erroNumber = 0;
                System.Drawing.Image oriImg, newImg;
                string strFePicSavePath = ConfigurationSettings.AppSettings["FePicSavePath"].ToString();
                string strFePicThumbFormat = ConfigurationSettings.AppSettings["FePicThumbFormat"].ToString().ToLower();
                int intFeThumbWidth = Int32.Parse(ConfigurationSettings.AppSettings["FePicThumbWidth"]);
                string fileExt;                StringBuilder picInfo = new StringBuilder();

            if(Page.IsValid)
            {
                            for(int i = 0;i < Request.Files.Count; i++)
                {
                    HttpPostedFile PostedFile = Request.Files[i];
                    fileExt = (System.IO.Path.GetExtension(PostedFile.FileName)).ToString().ToLower();

                    imgNameOnly = System.IO.Path.GetFileName(PostedFile.FileName);
                    if(fileExt == ".jpg" || fileExt == ".gif" || fileExt == ".png")
                    {                        if(System.IO.File.Exists(strFePicSavePath + imgNameOnly) && (checkboxlistRewrite.Items[i].Selected == false))
                        {
                            erroNumber = erroNumber + 1;
                            picInfo.Append("<b>错误：</b>文件("+ (i+1) +") " + imgNameOnly + " 已经存在，请修改文件名<br>" );
                        }
                    }
                    else
                    {
                        erroNumber = erroNumber + 1;
                        picInfo.Append("<b>错误：</b>文件("+ (i+1) +") " + imgNameOnly + " 扩展名 " + fileExt + " 不被许可<br>" );
                    }                                }                if(erroNumber > 0)
                {
                    picInfo.Append("<font color=red>全部操作均未完成，请修改错误，再进行操作</font><br>");
                }
                else
                {
                    for(int i = 0;i < Request.Files.Count; i++)
                    {

                        HttpPostedFile PostedFile = Request.Files[i];
                        imgNameOnly = System.IO.Path.GetFileName(PostedFile.FileName);
                        imgNameNoExt = System.IO.Path.GetFileNameWithoutExtension(PostedFile.FileName);
                        imgExt = System.IO.Path.GetExtension(PostedFile.FileName).ToString().ToLower();


                        oriImg = System.Drawing.Image.FromStream(PostedFile.InputStream);
                        newImg = oriImg.GetThumbnailImage(intFeThumbWidth, intFeThumbWidth * oriImg.Height/oriImg.Width,null,new System.IntPtr(0));
                        switch(imgExt)
                        {
                            //case ".jpeg":
                            case ".jpg":
                                oriImg.Save(strFePicSavePath + imgNameOnly , System.Drawing.Imaging.ImageFormat.Jpeg);
                                break;
                            case ".gif":
                                oriImg.Save(strFePicSavePath + imgNameOnly , System.Drawing.Imaging.ImageFormat.Gif);
                                break;
                            case ".png":
                                oriImg.Save(strFePicSavePath + imgNameOnly , System.Drawing.Imaging.ImageFormat.Png);
                                break;
                        }

                        //oriImg.Save(ConfigurationSettings.AppSettings["FePicSavePath"] + imgNameNoExt + ".jpg", System.Drawing.Imaging.ImageFormat.Jpeg);

                        switch(strFePicThumbFormat)
                        {
                                //jpeg format can get the smallest file size, and the png is the largest size
                            //case "jpeg":
                            case "jpg":
                                newImg.Save(strFePicSavePath + imgNameOnly + "_thumb.jpg",System.Drawing.Imaging.ImageFormat.Jpeg);
                                imgThumbnail = imgNameOnly + "_thumb.jpg";
                                break;
                            case "gif":
                                newImg.Save(strFePicSavePath + imgNameOnly + "_thumb.gif",System.Drawing.Imaging.ImageFormat.Gif);
                                imgThumbnail = imgNameOnly + "_thumb.gif";
                                break;
                            case "png":
                                newImg.Save(strFePicSavePath + imgNameOnly + "_thumb.png",System.Drawing.Imaging.ImageFormat.Png);
                                imgThumbnail = imgNameOnly + "_thumb.png";
                                break;
                            default:
                                newImg.Save(strFePicSavePath + imgNameOnly + "_thumb.jpg",System.Drawing.Imaging.ImageFormat.Jpeg);
                                imgThumbnail = imgNameOnly + "_thumb.jpg";
                                break;

                        }//switch

                        picInfo.Append("<b>文件　名：</b>" + imgNameOnly + " ( " + oriImg.Width + " x " + oriImg.Height + " ) " + PostedFile.ContentLength/1024 + "KB<br>");
                        picInfo.Append("<b>缩略图名：</b>" + imgThumbnail + " ( " + newImg.Width + " x " + newImg.Height + " )<br><br>");

                        oriImg.Dispose();
                        newImg.Dispose();

                    }//for
                    picInfo.Append("<font color=red>所有操作成功</font><br>");                }// if erronumber = 0

            }
            else
            {
                picInfo.Append("<font color=red>有错误，请检查。操作未成功</font><br>");            }            lblPicInfo.Text = picInfo.ToString();        }

http://www.codeproject.com/aspnet/fileupload.asp?target=UPload

http://www.csdn.net/develop/read_article.asp?id=20937

CSDN - 文档中心 - .net

标题     用ASP.NET上传图片并生成可带版权信息的缩略图    xiahouwen（原作）

关键字     缩略图,上传,

<%@ Page Language="C#" ResponseEncoding="gb2312" %>
<%@ import Namespace="System" %>
<%@ import Namespace="System.IO" %>
<%@ import Namespace="System.Drawing" %>
<%@ import Namespace="System.Drawing.Imaging" %>
<script runat="server">    void Page_Load(Object sender, EventArgs e)
    {
        if(!Page.IsPostBack)
        {
   ImgPreview.Visible=false;
        }
    }
    void GetThumbnailImage(int width,int height,string strInfo,int left,int right)
    {
        string file="Uploads/"+uploadFile.PostedFile.FileName.Substring(uploadFile.PostedFile.FileName.LastIndexOf('\\')+1);
  string newfile="Uploads/"+uploadFile.PostedFile.FileName.Substring(uploadFile.PostedFile.FileName.LastIndexOf('\\')+1)+".jpg";
        string strAdd=strInfo;
        System.Drawing.Image oldimage = System.Drawing.Image.FromFile(Server.MapPath(file));
        System.Drawing.Image thumbnailImage =
        oldimage.GetThumbnailImage(width, height,new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback), IntPtr.Zero);
        Response.Clear();
        Bitmap output=new Bitmap(thumbnailImage);
        Graphics g=Graphics.FromImage(output);
        g.DrawString(strAdd,new Font("Courier New", 14),new SolidBrush(Color.Red),left,right);
  output.Save(Server.MapPath(newfile),System.Drawing.Imaging.ImageFormat.Jpeg);
                Response.ContentType = "image/gif";
  ImgPreview.Visible=true;
  ImgPreview.ImageUrl=newfile;
    }
    bool ThumbnailCallback()
    {
             return true;
    }

    void Button_Click(object sender, EventArgs e)
    {
        int width,height,left,right;
        string strAddInfo=txtAddInfo.Text;
        width=Int32.Parse(txtWidth.Text);
        height=Int32.Parse(txtHeight.Text);
        left=Int32.Parse(txtLeft.Text);
        right=Int32.Parse(txtRight.Text);
        if(!(uploadFile.PostedFile.ContentLength>0))
        {
            lblErrInfo.Text="没有选择文件";
        }
        else
        {

            string path = Server.MapPath("./Uploads/"+uploadFile.PostedFile.FileName.Substring(uploadFile.PostedFile.FileName.LastIndexOf('\\')+1));
            if(File.Exists(path))
            {
                lblErrInfo.Text="已经有同名文件";
            }
            else
            {
                uploadFile.PostedFile.SaveAs(path);
    GetThumbnailImage(width,height,strAddInfo,left,right);
            }
        }
    }
</script>
<html>
<head>
</head>
<body>
    <form method="post" enctype="multipart/form-data" runat="server">
        <p>
            <input id="uploadFile" type="file" runat="server" />
            <asp:Label id="lblErrInfo" runat="server" forecolor="Red"></asp:Label>
        </p>
        <p>
            width:<asp:TextBox id="txtWidth" runat="server" Width="40px">100</asp:TextBox>
             height:<asp:TextBox id="txtHeight" runat="server" Width="40px">150</asp:TextBox>
             
        </p>
        <p>
            添加信息：<asp:TextBox id="txtAddInfo" runat="server"> AspxBoy.Com</asp:TextBox>
        </p>
        <p>
            信息位置：left:<asp:TextBox id="txtLeft" runat="server" Width="40px">10</asp:TextBox>
             right:<asp:TextBox id="txtRight" runat="server" Width="40px">135</asp:TextBox>
        </p>
        <p>
             
            <input id="button" type="button" value="上传生成所略图" onServerClick="Button_Click" runat="server" />
        </p>
  <p><asp:Image id="ImgPreview" runat="server"></asp:Image>
  </p>
        
    </form>
</body>
</html>

图片上传，给你一个例子：
1.在.aspx文件中：（添加enctype="multipart/form-data"）
<form id="upload_img_common" method="post" runat="server" enctype="multipart/form-data"><span id="Message" runat="server"></span><INPUT id="File1" type="file" name="File1" runat="server">2.在.aspx.cs中：
using System.IO;
protected System.Web.UI.HtmlControls.HtmlGenericControl Message;
protected System.Web.UI.HtmlControls.HtmlInputFile File1;private void btnOK_Click(object sender, System.EventArgs e)
{
string filepath=Server.MapPath("img/"+Path.GetFileName(File1.PostedFile.FileName));
if(File.Exists(filepath))
{
Message.InnerHtml="上传文件重名，请改名后再上传！";
Message.Style["Color"]="red";
return;
}
else
{
if(File1.PostedFile!=null)
try
{
File1.PostedFile.SaveAs(filepath);
Message.InnerHtml="<b>成功上传！</b>";
}
catch (Exception exc)
{
Message.InnerHtml="保存文件时出错<b>" + filepath + "</b><br>"+ exc.ToString();
}
} }

asp.net上传图片并同时生成缩略图
http://www.pconline.com.cn/pcedu/empolder/net/10309/215678.html

<%@ Import Namespace="System.IO" %>
<html>
<head>
   <script language="VB" runat="server">      'UploadButton1 上传按纽
      'UploadFile1 上传文件名
      'SaveasFile1 另存文件名
      'SavePath1 上传绝对路径
      'Error1  提示的错误信息      Sub UploadButton1_Click(sender As Object, e As EventArgs)   Dim SavePath1 As String="C:\"         If UploadFile1.Value = "" Then
            Error1.InnerHtml = "错误：您必须选择一个文件!"
            Return
         End If         If SaveasFile1.Value = "" Then
            Error1.InnerHtml = "错误：必须输入一个文件名!"
            Return
         End If         If Not IsNothing(UploadFile1.PostedFile) Then
            Dim filepath As String = Path.Combine(SavePath1, Path.GetFileName(SaveasFile1.Value))
            Try
               UploadFile1.PostedFile.SaveAs(filepath)
               Error1.InnerHtml = "文件成功上载到服务器上的 " & filepath
            Catch Exc As Exception
               Error1.InnerHtml = "文件上载出错<b>" & filepath & "</b><br>" & Exc.ToString()
            End Try
         End If
      End Sub
   </script>
</head>
<body>   <form enctype="multipart/form-data" runat="server">
       选择上载文件：<input id="UploadFile1" type=file runat="server"><br>
       另存为文件名：<input id="SaveasFile1" type="text" runat="server">（需后缀）<br>
       <input type=button id="UploadButton1" value="上传" OnServerClick="UploadButton1_Click" runat="server"><br>
       <div id="Error1" style="color:red" runat="server" />
   </form></body>
</html>

我昨天做了一天，上传多少图片都可以了
我用了HtmlInputFile控件，
简单的说upload.PostedFile.SaveAs(upurl);（upload是HtmlInputFile控件）
你还可以加一些验证上传文件大小，类型等方法，都可以在upload.PostedFile.中找到
我是把文件夹名存到数据库中的，所以可以上传多张，

调试易

如何用ASP.NET实现图片上传？（80分）

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