超强C#图片上传，加水印，自动生成缩略图源代码(联高原创)

发表：联高软件www.legalsoft.com.cn，本文被阅读：1 次

北京联高软件开发有限公司倾情奉献经过测试的超强C#图片上传，加水印，自动生成缩略图源代码。可以指定水印位置、文字；可以设置缩略图背景颜色，边框及其颜色，阴影及其颜色；可以指定缩略图质量；支持GIF,JPEG,JPG,PNG,BMP,TIFF等多种格式图片文件。

<%@ Page Language="C#" AutoEventWireup="true" %>
<%@ Import Namespace="System" %>
<%@ Import Namespace="System.IO" %>
<%@ Import Namespace="System.Net" %>
<%@ Import NameSpace="System.Web" %>
<%@ Import NameSpace="Legalsoft.Images" %>
<script language="C#" runat="server">

protected void Page_Load(object sender, EventArgs e)
{
if (IsPostBack)
{
foreach (string f in Request.Files.AllKeys)
{
// 查找是否存在指定的目，如果允许创建目录，则创建之。
string f_path = TextBox1.Text;
if (!System.IO.Directory.Exists(Server.MapPath(f_path)))
{
if (CheckBox1.Checked)
{
System.IO.Directory.CreateDirectory(Server.MapPath(f_path));
}
else
{
return;
}
}
// 获取提交的文件名，包含的全部的目录信息；需要提取其文件名（名字＋后缀）
HttpPostedFile file = Request.Files[f];
string fname = file.FileName.ToLower();
fname = fname.Replace("\\", "/");
int lsub = fname.LastIndexOf("/");
if (lsub >= 0)
{
fname = fname.Substring(lsub + 1, fname.Length - lsub - 1);
string[] fa_ext = fname.Split(".");
string f_pre = fa_ext[fa_ext.Length - 2];
string f_ext = fa_ext[fa_ext.Length - 1];
if (f_ext == "gif" || f_ext == "jpg" || f_ext == "jpeg")
{
file.SaveAs(Server.MapPath(f_path) + "/" + f_pre + "." + f_ext);

XImage img = new XImage();
// 添加水印
if (TextBox2.Text.Trim() != "")
{
img.markPosition = DropDownList5.Items[DropDownList5.SelectedIndex].Text;
img.Mark(f_path + f_pre + "." + f_ext, TextBox2.Text);
}

// 如果需要生成所略图
if (CheckBox2.Checked)
{
int tWidth = Int32.Parse(TextBox3.Text);
int tHeight = Int32.Parse(TextBox4.Text);
img.tBackground = img.ToColor(DropDownList1.Items[DropDownList1.SelectedIndex].Text);
img.tBorder = img.ToColor(DropDownList2.Items[DropDownList2.SelectedIndex].Text);
img.tShadow = img.ToColor(DropDownList3.Items[DropDownList3.SelectedIndex].Text);
img.tQuality = img.ToQuality(DropDownList4.Items[DropDownList4.SelectedIndex].Text);
img.ToThumbnail(f_path + f_pre + "." + f_ext, f_path + f_pre + "_thumb." + f_ext, tWidth, tHeight);
}
}
}
}
}
}

</script>

<!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 id="Head1" runat="server">
<title>C#图片上传及生成缩略图,添加水印的代码</title>
<meta name="keywords" content="C#文件上传的实例代码"/>
<meta name="description" content="在线式代码自动生成器SharpOnline只需要数据库Table定义就自动生成网站的全套C#源代码与页面（包括数据查询于操作、输入页面、编辑页面及其后台页面）。" />
<meta http-equiv="content-type" content="text/html; charset=gb2312"/>
<meta http-equiv="content-language" content="zh-cn"/>
<link href="/favicon.ico" type="image/x-icon" rel="shortcut icon"/>
<link href="/favicon.ico" type="image/x-icon" rel="bookmark"/>
<meta http-equiv="imagetoolbar" content="no"/>
<meta name="distribution" content="global"/>
<link href="/common/style.css" rel="stylesheet" type="text/css"/>
</head>
<body>
<form id="form1" runat="server">
<center>

<div style="width:938px;background-color:#FFFFFF;">

<table width="938" style="background-color:#F0F0FF;padding:8px;line-height:24px;text-align:left;" cellpadding="0" cellspacing="0">
<tr>
<td align="right">保存的目录：</td>
<td>
<asp:TextBox ID="TextBox1" runat="server">/UploadedFiles/</asp:TextBox>
<asp:CheckBox ID="CheckBox1" runat="server" Checked="true" />自动创建目录
</td>
</tr>
<tr>
<td align="right">添加水印字：</td>
<td>
文字：<asp:TextBox ID="TextBox2" runat="server">50018.COM</asp:TextBox> (可以为空，则不加水印)<br />
位置：
<asp:DropDownList ID="DropDownList5" runat="server">
<asp:ListItem Selected="True">左下角</asp:ListItem>
<asp:ListItem>左上角</asp:ListItem>
<asp:ListItem>右下角</asp:ListItem>
<asp:ListItem>右上角</asp:ListItem>
<asp:ListItem>图片中间</asp:ListItem>
</asp:DropDownList><br />
</td>
</tr>
<tr>
<td align="right">生成缩略图：</td>
<td>
<asp:CheckBox ID="CheckBox2" Checked="true" runat="server" />生成缩略图<br />
宽度： <asp:TextBox ID="TextBox3" runat="server">100</asp:TextBox><br />
高度： <asp:TextBox ID="TextBox4" runat="server">75</asp:TextBox><br />
背景：
<asp:DropDownList ID="DropDownList1" runat="server">
<asp:ListItem Selected="True">无色</asp:ListItem>
<asp:ListItem>白色</asp:ListItem>
<asp:ListItem>红色</asp:ListItem>
<asp:ListItem>蓝色</asp:ListItem>
<asp:ListItem>黄色</asp:ListItem>
<asp:ListItem>黑色</asp:ListItem>
<asp:ListItem>绿色</asp:ListItem>
<asp:ListItem>紫色</asp:ListItem>
<asp:ListItem>灰色</asp:ListItem>
</asp:DropDownList><br />
边框：
<asp:DropDownList ID="DropDownList2" runat="server">
<asp:ListItem Selected="True">无色</asp:ListItem>
<asp:ListItem>白色</asp:ListItem>
<asp:ListItem>红色</asp:ListItem>
<asp:ListItem>蓝色</asp:ListItem>
<asp:ListItem>黄色</asp:ListItem>
<asp:ListItem>黑色</asp:ListItem>
<asp:ListItem>绿色</asp:ListItem>
<asp:ListItem>紫色</asp:ListItem>
<asp:ListItem>灰色</asp:ListItem>
</asp:DropDownList><br />
阴影：
<asp:DropDownList ID="DropDownList3" runat="server">
<asp:ListItem Selected="True">无色</asp:ListItem>
<asp:ListItem>白色</asp:ListItem>
<asp:ListItem>红色</asp:ListItem>
<asp:ListItem>蓝色</asp:ListItem>
<asp:ListItem>黄色</asp:ListItem>
<asp:ListItem>黑色</asp:ListItem>
<asp:ListItem>绿色</asp:ListItem>
<asp:ListItem>紫色</asp:ListItem>
<asp:ListItem>灰色</asp:ListItem>
</asp:DropDownList><br />
质量：
<asp:DropDownList ID="DropDownList4" runat="server">
<asp:ListItem Selected="True">100%</asp:ListItem>
<asp:ListItem>90%</asp:ListItem>
<asp:ListItem>80%</asp:ListItem>
<asp:ListItem>60%</asp:ListItem>
<asp:ListItem>50%</asp:ListItem>
<asp:ListItem>40%</asp:ListItem>
</asp:DropDownList>
</td>
</tr>
<tr>
<td align="right">请选择文件：</td>
<td><asp:FileUpload ID="FileUpload1" runat="server" /></td>
</tr>
<tr>
<td align="right"></td>
<td><asp:Button ID="Button2" runat="server" Text="提交" Width="88px" /></td>
</tr>
</table>

</div>

</center>
</form>
</body>
</html>

using System;
using System.Data;
using System.Data.SqlClient;
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.Text;
using System.Text.RegularExpressions;
using System.Drawing;
using System.Drawing.Imaging;
using System.Collections;
using System.ComponentModel;
namespace Legalsoft.Images
{
    /// <summary>
    /// News 的摘要说明
    /// </summary>
    public class XImage
    {
        public Color tBackground;
        public Color tBorder;
        public Color tShadow;
        public int tQuality;
        public string markPosition;
        /// <summary>
        /// 图片参数预定义
        /// </summary>
        static Hashtable htmimes = new Hashtable();
        internal readonly string AllowExt = ".jpe|.jpeg|.jpg|.png|.tif|.tiff|.bmp|.gif";
        public XImage()
        {
            tBackground = Color.Transparent;
            tBorder = Color.Transparent;
            tShadow = Color.Transparent;
            tQuality = 100;
            markPosition = "左下角";
            #region 图片类型预定义
            htmimes[".jpe"]="image/jpeg";
            htmimes[".jpeg"] = "image/jpeg";
            htmimes[".jpg"] = "image/jpeg";
            htmimes[".png"] = "image/png";
            htmimes[".tif"] = "image/tiff";
            htmimes[".tiff"] = "image/tiff";
            htmimes[".bmp"] = "image/bmp";
            htmimes[".gif"] = "image/gif";
            #endregion 
        }
        #region 下载指定URL图片并保存
        /// <summary>
        /// 下载指定URL的文件并保存到指定目录
        /// </summary>
        /// <param name="strUrl"></param>
        public void DownloadImage(string strUrl, string file)
        {
            System.Net.WebClient wc = new System.Net.WebClient();
            wc.DownloadFile(strUrl, file);
        }
        #endregion
        #region C#自动生成缩略图
        /// <summary>
        /// 按给定名字确定颜色
        /// </summary>
        /// <param name="name"></param>
        /// <returns></returns>
        public Color ToColor(string name)
        {
            if (name == "白色") return Color.White;
            if (name == "红色") return Color.Red;
            if (name == "蓝色") return Color.Blue;
            if (name == "绿色") return Color.Green;
            if (name == "黑色") return Color.Black;
            if (name == "灰色") return Color.DarkGray;
            if (name == "黄色") return Color.Yellow;
            if (name == "紫色") return Color.Cyan;
            if (name == "无色") return Color.Transparent;
            return Color.Transparent;
        }
        /// <summary>
        /// 按名字设置各种颜色，可以自行扩充:)
        /// </summary>
        /// <param name="name"></param>
        /// <returns></returns>
        public int ToQuality(string name)
        {
            return Int32.Parse(name.Replace("%", ""));
        }
        /// <summary> 
        /// 获取图像编码解码器的所有相关信息 
        /// </summary> 
        /// <param name="mimeType">包含编码解码器的多用途网际邮件扩充协议 (MIME) 类型的字符串</param> 
        /// <returns>返回图像编码解码器的所有相关信息</returns> 
        private static ImageCodecInfo GetCodecInfo(string mimeType)
        {
            ImageCodecInfo[] CodecInfo = ImageCodecInfo.GetImageEncoders();
            foreach (ImageCodecInfo ici in CodecInfo)
            {
                if (ici.MimeType == mimeType) return ici;
            }
            return null;
        }
        /// <summary> 
        /// 检测扩展名的有效性 
        /// </summary> 
        /// <param name="sExt">文件名扩展名</param> 
        /// <returns>如果扩展名有效,返回true,否则返回false.</returns> 
        private bool CheckValidExt(string sExt)
        {
            bool flag = false;
            string[] aExt = AllowExt.Split("|");
            foreach (string filetype in aExt)
            {
                if (filetype.ToLower() == sExt)
                {
                    flag = true;
                    break;
                }
            }
            return flag;
        }
        /// <summary> 
        /// 保存图片 
        /// </summary> 
        /// <param name="image">Image 对象</param> 
        /// <param name="savePath">保存路径</param> 
        /// <param name="ici">指定格式的编解码参数</param> 
        private void SaveImage(System.Drawing.Image image, string savePath, ImageCodecInfo ici)
        {
            //设置 原图片 对象的 EncoderParameters 对象 
            EncoderParameters parameters = new EncoderParameters(1);
            parameters.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, ((long)tQuality));
            image.Save(savePath, ici, parameters);
            parameters.Dispose();
        }
        /// <summary> 
        /// 生成缩略图 
        /// </summary> 
        /// <param name="sourceImagePath">原图片路径(相对路径)</param> 
        /// <param name="thumbnailImagePath">生成的缩略图路径,如果为空则保存为原图片路径(相对路径)</param> 
        /// <param name="thumbnailImageWidth">缩略图的宽度（高度与按源图片比例自动生成）</param> 
        public void ToThumbnail(string sourceImagePath, string thumbnailImagePath, int thumbnailImageWidth, int thumbnailImageHeight )
        {
            // 1.先检查图片格式等信息
            string ThumbnailImagePath = thumbnailImagePath;
            string SourceImagePath = sourceImagePath;
            string sExt = SourceImagePath.Substring(SourceImagePath.LastIndexOf(".")).ToLower();
            if (SourceImagePath.ToString() == System.String.Empty)
            {
                throw new NullReferenceException("SourceImagePath is null!");
            }
            if (!CheckValidExt(sExt))
            {
                throw new ArgumentException("原图片文件格式不正确,支持的格式有[ " + AllowExt + " ]", "SourceImagePath");
            }
            // 从原图片创建 Image 对象 
            System.Drawing.Image image = System.Drawing.Image.FromFile(HttpContext.Current.Server.MapPath(SourceImagePath));
            // 2.计算图片的位置、尺寸等信息
            int tWidth, tHeight, tLeft, tTop;
            double fScale = (double)thumbnailImageHeight / (double)thumbnailImageWidth; // 高度宽度比
            if (((double)image.Width * fScale) > (double)image.Height) // 如果原图比较宽
            {
                tWidth = thumbnailImageWidth;
                tHeight = (int)((double)image.Height * (double)tWidth / (double)image.Width);
                tLeft = 0;
                tTop = (thumbnailImageHeight-tHeight)/2;
            }
            else
            {
                tHeight = thumbnailImageHeight;
                tWidth = (int)((double)image.Width * (double)tHeight / (double)image.Height);
                tLeft = (thumbnailImageWidth-tWidth)/2;
                tTop = 0;
            }
            if (tLeft < 0) tLeft = 0;
            if (tTop < 0) tTop = 0;
            if (tBorder != Color.Transparent)
            {
                tWidth -= 2;
                tHeight -= 2;
                tLeft++;
                tTop++;
            }
            if (tShadow != Color.Transparent)
            {
                tWidth -= 1;
                tHeight -= 1;
            }
            //用指定的大小和格式初始化 Bitmap 类的新实例 
            //Bitmap bitmap = new Bitmap(ThumbnailImageWidth, num, PixelFormat.Format32bppArgb);
            Bitmap bitmap = new Bitmap(thumbnailImageWidth, thumbnailImageHeight, PixelFormat.Format32bppArgb);
            //从指定的 Image 对象创建新 Graphics 对象 
            Graphics graphics = Graphics.FromImage(bitmap);
            //清除整个绘图面并以透明背景色填充
            if (tBackground != Color.Transparent)
            {
                graphics.Clear(tBackground);
            }
            else
            {
                graphics.Clear(Color.Transparent);
            }
            // 添加阴影
            if (tShadow != Color.Transparent)
            {
                Pen shPen = new Pen(tShadow);
                graphics.DrawLine(shPen, new Point(1, thumbnailImageHeight-1), new Point(thumbnailImageWidth-1, thumbnailImageHeight-1));
                graphics.DrawLine(shPen, new Point(thumbnailImageWidth-1, 1), new Point(thumbnailImageWidth-1, thumbnailImageHeight-1));
            }
            // 添加边框
            if (tBorder != Color.Transparent)
            {
                Pen bdPen = new Pen(tBorder);
                if (tShadow != Color.Transparent)
                {
                    graphics.DrawRectangle(bdPen, new Rectangle(0, 0, thumbnailImageWidth-2, thumbnailImageHeight-2));
                }
                else
                {
                    graphics.DrawRectangle(bdPen, new Rectangle(0, 0, thumbnailImageWidth-1, thumbnailImageHeight-1));
                }
            }
            //在指定位置并且按指定大小绘制 原图片 对象 
            graphics.DrawImage(image, new Rectangle(tLeft, tTop, tWidth, tHeight));
            image.Dispose();
            try
            {
                //将此 原图片 以指定格式并用指定的编解码参数保存到指定文件 
                string savepath = (ThumbnailImagePath == null ? SourceImagePath : ThumbnailImagePath);
                SaveImage(bitmap, HttpContext.Current.Server.MapPath(savepath), GetCodecInfo((string)htmimes[sExt]));
            }
            catch (System.Exception e)
            {
                throw e;
            }
            finally
            {
                bitmap.Dispose();
                graphics.Dispose();
            }
        }
        #endregion
        #region C#给图片添加水印
        public void Mark(string sourceImagePath, string markString)
        {
            // 1.先检查图片格式等信息
            string markImagePath = sourceImagePath;
            string SourceImagePath = sourceImagePath;
            string sExt = SourceImagePath.Substring(SourceImagePath.LastIndexOf(".")).ToLower();
            if (SourceImagePath.ToString() == System.String.Empty)
            {
                throw new NullReferenceException("SourceImagePath is null!");
            }
            if (!CheckValidExt(sExt))
            {
                throw new ArgumentException("原图片文件格式不正确,支持的格式有[ " + AllowExt + " ]", "SourceImagePath");
            }
            // 从原图片创建 Image 对象 
            System.Drawing.Image image = System.Drawing.Image.FromFile(HttpContext.Current.Server.MapPath(SourceImagePath));
            //用指定的大小和格式初始化 Bitmap 类的新实例 
            Bitmap bitmap = new Bitmap(image.Width, image.Height, PixelFormat.Format32bppArgb);
            //从指定的 Image 对象创建新 Graphics 对象 
            Graphics graphics = Graphics.FromImage(bitmap);
            //在指定位置并且按指定大小绘制 原图片 对象 
            graphics.DrawImage(image, new Rectangle(0, 0, image.Width, image.Height));
            #region 绘制水印
            // 设置水印字体
            int fHeight = image.Height/5;
            if(fHeight>16) fHeight = 16;
            Font drawFont = new Font("Arial", fHeight);
            // 设置水印文字位置，默认为左下角
            float x = 4;
            float y = image.Height - drawFont.Height - 4;
            if (markPosition == "左上角")
            {
                y = 4;
            }
            if (markPosition == "右上角")
            {
                x = image.Width - markString.Length * fHeight / 2 - fHeight;
                y = 4;
            }
            if (markPosition == "右下角")
            {
                x = image.Width - markString.Length * fHeight / 2 - fHeight;
            }
            if (markPosition == "图片中间")
            {
                x = image.Width / 2 - markString.Length * fHeight / 2;
                y = image.Height / 2 - fHeight / 2;
            }
            StringFormat drawFormat = new StringFormat();
            drawFormat.FormatFlags = StringFormatFlags.NoWrap;
            // 设置水印文字颜色，先绘制一个黑色字作为阴影，再绘制白色字，这样比较显眼；
            SolidBrush drawBrush = new SolidBrush(Color.Black);
            graphics.DrawString(markString, drawFont, drawBrush, x, y, drawFormat);
            drawBrush.Color = Color.White;
            graphics.DrawString(markString, drawFont, drawBrush, x-1, y-1, drawFormat);
            #endregion
            image.Dispose();
            try
            {
                //将此 原图片 以指定格式并用指定的编解码参数保存到指定文件 
                string savepath = SourceImagePath;
                SaveImage(bitmap, HttpContext.Current.Server.MapPath(savepath), GetCodecInfo((string)htmimes[sExt]));
            }
            catch (System.Exception e)
            {
                throw e;
            }
            finally
            {
                bitmap.Dispose();
                graphics.Dispose();
            }
        }
        #endregion
    }
}

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