SWFUpload实现原图及缩略图上传保存清空

 1.修改类 Thumbnail

using System;
using System.Data;
using System.Configuration;
using System.Collections;
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;
using System.Collections.Generic;

public partial class upload : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        System.Drawing.Image thumbnail_image = null;
        System.Drawing.Image original_image = null;
        System.Drawing.Bitmap final_image = null;
        System.Drawing.Graphics graphic = null;
        MemoryStream ms = null;
        MemoryStream maxms = null;
        try
        {
            // Get the data
            HttpPostedFile jpeg_image_upload = Request.Files["Filedata"];

            // Retrieve the uploaded image
            original_image = System.Drawing.Image.FromStream(jpeg_image_upload.InputStream);
            
            // Calculate the new width and height
            int width = original_image.Width;
            int height = original_image.Height;
            int target_width = 100;
            int target_height = 75;
            int new_width, new_height;

            float target_ratio = (float)target_width / (float)target_height;
            float image_ratio = (float)width / (float)height;

            if (target_ratio > image_ratio)
            {
                new_height = target_height;
                new_width = (int)Math.Floor(image_ratio * (float)target_height);
            }
            else
            {
                new_height = (int)Math.Floor((float)target_width / image_ratio);
                new_width = target_width;
            }

            new_width = new_width > target_width ? target_width : new_width;
            new_height = new_height > target_height ? target_height : new_height;


            // Create the thumbnail

            // Old way
            //thumbnail_image = original_image.GetThumbnailImage(new_width, new_height, null, System.IntPtr.Zero);
            // We don't have to create a Thumbnail since the DrawImage method will resize, but the GetThumbnailImage looks better
            // I've read about a problem with GetThumbnailImage. If a jpeg has an embedded thumbnail it will use and resize it which
            //  can result in a tiny 40x40 thumbnail being stretch up to our target size


            final_image = new System.Drawing.Bitmap(target_width, target_height);
            graphic = System.Drawing.Graphics.FromImage(final_image);
            graphic.FillRectangle(new System.Drawing.SolidBrush(System.Drawing.Color.Black), new System.Drawing.Rectangle(0, 0, target_width, target_height));
            int paste_x = (target_width - new_width) / 2;
            int paste_y = (target_height - new_height) / 2;
            graphic.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic; /**//* new way */
            //graphic.DrawImage(thumbnail_image, paste_x, paste_y, new_width, new_height); 
            graphic.DrawImage(original_image, paste_x, paste_y, new_width, new_height);

            // Store the thumbnail in the session (Note: this is bad, it will take a lot of memory, but this is just a demo)#

            

            ms = new MemoryStream();
            //final_image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);

            final_image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
            修改部分开始#region 修改部分开始
            maxms = new MemoryStream();
            original_image.Save(maxms, System.Drawing.Imaging.ImageFormat.Jpeg);
            //----------------------------------------------------------------
            // Store the data in my custom Thumbnail object
            string thumbnail_id = DateTime.Now.ToString("yyyyMMddHHmmssfff");

            Thumbnail thumb = new Thumbnail(thumbnail_id,maxms.GetBuffer(), ms.GetBuffer());
            #endregion 修改部分结束

            // Put it all in the Session (initialize the session if necessary)            
            List<Thumbnail> thumbnails = Session["file_info"] as List<Thumbnail>;
            if (thumbnails == null)
            {
                thumbnails = new List<Thumbnail>();
                Session["file_info"] = thumbnails;
            }
            thumbnails.Add(thumb);

            Response.StatusCode = 200;
            Response.Write(thumbnail_id);
        }
        catch
        {
            // If any kind of error occurs return a 500 Internal Server error
            Response.StatusCode = 500;
            Response.Write("An error occured");
            Response.End();
        }
        finally
        {
            // Clean up
            if (final_image != null) final_image.Dispose();
            if (graphic != null) graphic.Dispose();
            if (original_image != null) original_image.Dispose();
            if (thumbnail_image!= null )thumbnail_image.Dispose();
            if (ms != null) ms.Close();
            Response.End();
        }
    
    }
}

 

2.修改upload.aspx.cs

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Web.UI;
/**//// <summary>
/// Summary description for Thumbnail
/// </summary>
public class Thumbnail
{
    public Thumbnail(string id, byte[] data, byte[] minidata)
    {
        this.ID = id;
        this.Data = data;
        this.miniData = minidata;
    }

    private string id;
    public string ID
    {
        get
        {
            return this.id;
        }
        set
        {
            this.id = value;
        }
    }

    private byte[] max_data;
    public byte[] Data
    {
        get
        {
            return this.max_data;
        }
        set
        {
            this.max_data = value;
        }
    }

    private byte[] thumbnail_data;
    public byte[] miniData
    {
        get
        {
            return this.thumbnail_data;
        }
        set
        {
            this.thumbnail_data = value;
        }
    }    
}

 

3.保存按钮事件

    protected void btnSave_Click(object sender, EventArgs e)
    {
        if (Session["file_info"] != null)
        {
            List<Thumbnail> thumbnails = Session["file_info"] as List<Thumbnail>;

            string UploadPath = Server.MapPath("~/picupload/");
            string strPicName;
            string strPicMinName;
            string strCID;
            strCID = ddlpic.SelectedItem.Value;
            TArticle CA = new TArticle();
            foreach (Thumbnail img in thumbnails)
            {
                strPicName = img.ID + ".jpg";
                strPicMinName = img.ID + "_mini.jpg";
                FileStream fs = new FileStream(UploadPath + img.ID + ".jpg", FileMode.Create);
                BinaryWriter bw = new BinaryWriter(fs);
                bw.Write(img.Data);
                bw.Close();
                fs.Close();
                FileStream fss = new FileStream(UploadPath + img.ID + "_mini.jpg", FileMode.Create);
                BinaryWriter bww = new BinaryWriter(fss);
                bww.Write(img.miniData);
                bww.Close();
                fss.Close();
                //共用一个表文章表，原图片使用title,缩略图使用abstract
                //栏目分类使用状态为0的
                CA.ArticleCID = strCID;
                CA.ArticleTitle = strPicName;
                CA.ArticleAbstract = strPicMinName;
                CA.PicInsert();
            }
            Session.Remove("file_info");
            Response.Write("<script>alert('图片上传成功！');</script>");
            
        }
    }

 

总结：

int target_width = 100; //缩略图宽

int target_height = 75; //缩略图高

1.修改类Thumbnail，添加缩略图成员

2.修改上传控件,创建内存流存储缩略图数据流

3.上传保存，从Thumbnail类中读取数据流，使用文件流保存图片

    并保存到数据库中。

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