Asp.net上传图片同时生成缩略图和水印图后台代码（一）
后台代码：
using System;
using System.Collections;
using System.Configuration;
using System.Data;
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.IO;
using System.Net;
using System.Text.RegularExpressions;
public partial class BackManagement_ImagesUpload : System.Web.UI.Page
{
public string treePath = "";
public int imageW = 100;
public int imageH = 100;
protected void Page_Load(object sender, EventArgs e)
{
this.btnExit.Attributes.Add("Onclick", "window.close();"); //在本地关闭当前页，而不需要发送到服务器去关闭当前页时
if (!Page.IsPostBack)
{
txtDir.Text = "ImageUpload";
treePath = Server.MapPath("~/") + txtDir.Text.Trim() + "/";
TextBox4.Text = imageW.ToString();
TextBox5.Text = imageH.ToString();
}
}
protected void Btnload_Click(object sender, EventArgs e)
{
//如果保存图片的目录不存在，由创建它
treePath = Server.MapPath("~/") + txtDir.Text.Trim() + "/";
imageW = Convert.ToInt32(TextBox4.Text.ToString());
imageH = Convert.ToInt32(TextBox5.Text.ToString());
if (!File.Exists(treePath + "images")) //如果/ImageUpload/images不存在，则创建/ImageUpload/images，用于存放源图片
{
System.IO.Directory.CreateDirectory(treePath + "images");
}
if (!File.Exists(treePath + "thumbnails")) //如果/ImageUpload/thumbnails不存在，则创建/ImageUpload/thumbnails，用于存放缩略图片
{
System.IO.Directory.CreateDirectory(treePath + "thumbnails");
}
if (!File.Exists(treePath + "textImages")) //如果/ImageUpload/textImages不存在，则创建/ImageUpload/textImages，用于存文字水印图片
{
System.IO.Directory.CreateDirectory(treePath + "textImages");
}
if (!File.Exists(treePath + "waterImages")) //如果/ImageUpload/waterImages不存在，则创建/ImageUpload/waterImages，用于存图形水印图片
{
System.IO.Directory.CreateDirectory(treePath + "waterImages");
}
System.Web.HttpFileCollection files = System.Web.HttpContext.Current.Request.Files;
for (int i = 0; i < files.Count; i++)
{
System.Web.HttpPostedFile myFile = files[i];
string FileName = "";
FileName = System.IO.Path.GetFileName(myFile.FileName);
if (FileName.Length > 0)//有文件才执行上传操作再保存到数据库
{
string fileContentType = myFile.ContentType;
if (fileContentType == "image/bmp" || fileContentType == "image/gif" || fileContentType == "image/pjpeg")
{
string name = myFile.FileName; //返回文件在客户端的完全路径（包括文件名全称）
FileInfo file = new FileInfo(name); //FileInfo对象表示磁盘或网络位置上的文件。提供文件的路径，就可以创建一个FileInfo对象：
string fileName = file.Name; // 文件名称
string fileName_s = "x_" + file.Name; // 缩略图文件名称
string fileName_sy = "text_" + file.Name; // 水印图文件名称（文字）
string fileName_syp = "water_" + file.Name; // 水印图文件名称（图片）
string webFilePath = treePath + "images/" + fileName; // 服务器端文件路径
string webFilePath_s = treePath + "thumbnails/" + fileName_s; // 服务器端缩略图路径
string webFilePath_sy = treePath + "textImages/" + fileName_sy; // 服务器端带水印图路径(文字)
string webFilePath_syp = treePath + "waterImages/" + fileName_syp; // 服务器端带水印图路径(图片)
string webFilePath_sypf = Server.MapPath("~/images/water.png"); // 服务器端水印图路径(图片)
if (!File.Exists(webFilePath))
{
try
{
myFile.SaveAs(webFilePath); // 使用 SaveAs 方法保存文件
if (CheckBox1.Checked) //是否生成文字水印图
{
AddWaterText(webFilePath, webFilePath_sy);
}
if (CheckBox2.Checked) //是否生成图形水印图
{
AddWaterPic(webFilePath, webFilePath_syp, webFilePath_sypf);
}
MakeThumbnail(webFilePath, webFilePath_s, imageW, imageH, "Cut"); // 生成缩略图方法
lblMessage.Text = "提示：文件“" + fileName + "”成功上传，并生成“" + fileName_s + "”缩略图，文件类型为：" + myFile.ContentType + "，文件大小为：" + myFile.ContentLength + "B";
Image1.ImageUrl = "~/" + txtDir.Text.ToString() + "/images/" + fileName;
Image2.ImageUrl = "~/" + txtDir.Text.ToString() + "/thumbnails/" + "x_" + fileName;
TextBox1.Text = webFilePath;
TextBox2.Text = "/" + txtDir.Text.ToString() + "/images/" + fileName;
}
catch (Exception ex)
{
lblMessage.Text = "提示：文件上传失败，失败原因：" + ex.Message;
}
}
else
{
lblMessage.Text = "提示：文件已经存在，请重命名后上传";
}
}
else
{
lblMessage.Text = "提示：文件类型不符";
}
}
}
}
Asp.net上传图片同时生成缩略图和水印图后台代码（二）
/// <summary>/// 生成缩略图
/// </summary>
/// <param name="originalImagePath">源图路径（物理路径）</param>
/// <param name="thumbnailPath">缩略图路径（物理路径）</param>
/// <param name="width">缩略图宽度</param>
/// <param name="height">缩略图高度</param>
/// <param name="mode">生成缩略图的方式</param>
public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)
{
System.Drawing.Image originalImage = System.Drawing.Image.FromFile(originalImagePath);
int towidth = width;
int toheight = height;
int x = 0;
int y = 0;
int ow = originalImage.Width;
int oh = originalImage.Height;
switch (mode)
{
case "HW"://指定高宽缩放（可能变形）
break;
case "W"://指定宽，高按比例
toheight = originalImage.Height * width / originalImage.Width;
break;
case "H"://指定高，宽按比例
towidth = originalImage.Width * height / originalImage.Height;
break;
case "Cut"://指定高宽裁减（不变形）
if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
{
oh = originalImage.Height;
ow = originalImage.Height * towidth / toheight;
y = 0;
x = (originalImage.Width - ow) / 2;
}
else
{
ow = originalImage.Width;
oh = originalImage.Width * height / towidth;
x = 0;
y = (originalImage.Height - oh) / 2;
}
break;
default:
break;
}
//新建一个bmp图片
System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight);
//新建一个画板
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);
//设置高质量插值法
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
//设置高质量,低速度呈现平滑程度
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//清空画布并以透明背景色填充
g.Clear(System.Drawing.Color.Transparent);
//在指定位置并且按指定大小绘制原图片的指定部分
g.DrawImage(originalImage, new System.Drawing.Rectangle(0, 0, towidth, toheight),
new System.Drawing.Rectangle(x, y, ow, oh),
System.Drawing.GraphicsUnit.Pixel);
try
{
//以jpg格式保存缩略图
bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
}
catch (System.Exception e)
{
throw e;
}
finally
{
originalImage.Dispose();
bitmap.Dispose();
g.Dispose();
}
}
/**/
/// <summary>
/// 在图片上增加文字水印
/// </summary>
/// <param name="Path">原服务器图片路径</param>
/// <param name="Path_sy">生成的带文字水印的图片路径</param>
protected void AddWaterText(string Path, string Path_sy)
{
string addText = "深圳力致文化传播有限公司";
System.Drawing.Image image = System.Drawing.Image.FromFile(Path);
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image);
g.DrawImage(image, 0, 0, image.Width, image.Height);
System.Drawing.Font f = new System.Drawing.Font("Verdana", 10); //字体位置为左空10
System.Drawing.Brush b = new System.Drawing.SolidBrush(System.Drawing.Color.Green);
g.DrawString(addText, f, b, 14, 14); //字体大小为14X14
g.Dispose();
image.Save(Path_sy);
image.Dispose();
}
/**/
/// <summary>
/// 在图片上生成图片水印
/// </summary>
/// <param name="Path">原服务器图片路径</param>
/// <param name="Path_syp">生成的带图片水印的图片路径</param>
/// <param name="Path_sypf">水印图片路径</param>
protected void AddWaterPic(string Path, string Path_syp, string Path_sypf)
{
System.Drawing.Image image = System.Drawing.Image.FromFile(Path);
System.Drawing.Image copyImage = System.Drawing.Image.FromFile(Path_sypf);
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image);
g.DrawImage(copyImage, new System.Drawing.Rectangle(image.Width - copyImage.Width, image.Height - copyImage.Height, copyImage.Width, copyImage.Height), 0, 0, copyImage.Width, copyImage.Height, System.Drawing.GraphicsUnit.Pixel);
g.Dispose();
image.Save(Path_syp);
image.Dispose();
}
protected void Button2_Click(object sender, EventArgs e)
{
//自动保存远程图片
WebClient client = new WebClient();
//备用Reg:<img.*?src=([\"\'])(http:\/\/.+\.(jpg|gif|bmp|bnp))\1.*?>
Regex reg = new Regex("IMG[^>]*?src\\s*=\\s*(?:\"(?<1>[^\"]*)\"|'(?<1>[^\']*)')", RegexOptions.IgnoreCase);
MatchCollection m = reg.Matches(TextBox1.Text);
foreach (Match math in m)
{
string imgUrl = math.Groups[1].Value;
//在原图片名称前加YYMMDD重名名并上传
Regex regName = new Regex(@"\w+.(?:jpg|gif|bmp|png)", RegexOptions.IgnoreCase);
string strNewImgName = DateTime.Now.ToShortDateString().Replace("-", "") + regName.Match(imgUrl).ToString();
try
{
//保存图片
//client.DownloadFile(imgUrl, Server.MapPath("../ImageUpload/Auto/" + strNewImgName));
}
catch
{
}
finally
{
}
client.Dispose();
}
Response.Write("<script>alert('远程图片保存成功，保存路径为ImageUpload/auto')</script>");
}
}
摘自：http://hi.baidu.com/zhifeng_mo/blog/item/9b2be52086913aaa4723e84e.html
