asp.net 上传图片并作处理 水印 缩略图

代码具体如下：

asp.net 上传图片并作处理（生成缩略图 、在图片上增加文字水印、在图片上生成图片水印），经过测试！

方法类：

upFileClass.cs

using System;

using System.Data;

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;



/// <summary>

/// upFileClass 的摘要说明

/// </summary>

public class upFileClass

{

    public upFileClass()

    {

        //

        // TODO: 在此处添加构造函数逻辑

        //

    }



    /// <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>

    public static void AddShuiYinWord(string Path, string Path_sy)

    {

        string addText = "爱智旮旯";

        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", 16);

        System.Drawing.Brush b = new System.Drawing.SolidBrush(System.Drawing.Color.Blue);



        g.DrawString(addText, f, b, 15, 15);

        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>

    public static void AddShuiYinPic(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();

    }

}

Default.aspx代码：

<%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %>



<!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>asp.net 上传图片并作处理 水印 缩略图</title>

</head>

<body>

    <form id="form1" runat="server">

   <div>

        <asp:FileUpload ID="FileUpload1" runat="server" BorderColor="Gray" BorderWidth="1px" />

        <asp:Button ID="Button1" runat="server" onClick="Button1_Click" Text="上传" BorderColor="Gray" BorderWidth="1px" Width="70px" /><br />

        <asp:Label ID="Label1" runat="server"></asp:Label>

   </div>

    </form>

</body>

</html>

Default.aspx.cs代码：

using System;

using System.Data;

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.IO;



public partial class _Default : System.Web.UI.Page 

{

    protected void Page_Load(object sender, EventArgs e)

    {



    }

    protected void Button1_Click(object sender, EventArgs e)

    {

        if (FileUpload1.HasFile)

        {

            string fileContentType = FileUpload1.PostedFile.ContentType;

            if (fileContentType == "image/bmp" || fileContentType == "image/gif" || fileContentType == "image/pjpeg")

            {

                string name = FileUpload1.PostedFile.FileName; // 客户端文件路径



                FileInfo file = new FileInfo(name);

                string fileName = file.Name; // 文件名称

                string fileName_s = "s_" + file.Name; // 缩略图文件名称

                string fileName_sy = "sy_" + file.Name; // 水印图文件名称（文字）

                string fileName_syp = "syp_" + file.Name; // 水印图文件名称（图片）

                //以下路径可以根据情况进行修改

                string webFilePath = Server.MapPath("file/" + fileName); // 服务器端文件路径

                string webFilePath_s = Server.MapPath("file/" + fileName_s);　　// 服务器端缩略图路径

                string webFilePath_sy = Server.MapPath("file/" + fileName_sy);　// 服务器端带水印图路径(文字)

                string webFilePath_syp = Server.MapPath("file/" + fileName_syp);　// 服务器端带水印图路径(图片)

                //以下为水印图片的路径一定要先准备一张水印图片！

                string webFilePath_sypf = Server.MapPath("file/shuiyin.jpg");　// 服务器端水印图路径(图片)



                if (!File.Exists(webFilePath))

                {

                    try

                    {

                        FileUpload1.SaveAs(webFilePath); // 使用 SaveAs 方法保存文件

                        upFileClass.AddShuiYinWord(webFilePath, webFilePath_sy);

                        upFileClass.AddShuiYinPic(webFilePath, webFilePath_syp, webFilePath_sypf);

                        upFileClass.MakeThumbnail(webFilePath, webFilePath_s, 130, 130, "Cut"); // 生成缩略图方法

                        Label1.Text = "提示：文件“" + fileName + "”成功上传，并生成“" + fileName_s + "”缩略图，文件类型为：" + FileUpload1.PostedFile.ContentType + "，文件大小为：" + FileUpload1.PostedFile.ContentLength + "B";

                    }

                    catch (Exception ex)

                    {

                        Label1.Text = "提示：文件上传失败，失败原因：" + ex.Message;

                    }

                }

                else

                {

                    Label1.Text = "提示：文件已经存在，请重命名后上传";

                }

            }

            else

            {

                Label1.Text = "提示：文件类型不符";

            }



        }

    }



}