步步为营-71-asp.net的简单练习(图片处理)

2023-07-26 12:22:34

1 原有图片添加水印

1.1 封装一个类,用于获取文件路径

using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Web;

namespace _06_图片处理

{

    public static class FileHelper

    {

        public static string GetFilePath()

        {

            //02 创建文件保存路径

            string savePath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory + "Upload\\");

            //02-01 根据日期创建文件夹

            DateTime dt = DateTime.Now;

            savePath += dt.Year + "\\" + dt.Month + "\\" + dt.Day;

            if (!Directory.Exists(savePath))

            {

                //创建文件夹

                Directory.CreateDirectory(savePath);

            }

            //02-02文 件名为当前时间

            //savePath += "\\" + dt.ToString().Replace(':', '-') + ".gif";

            savePath += "\\" + dt.ToString().Replace(':', '-') ;

            return savePath;

        }

    }

}

FileHelper

1.2 html页面和ashx页面

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>

    <title></title>

</head>

<body>

    <form action="AddLogo.ashx" method="post" enctype="multipart/form-data">

        <input type="file" name="OrImg" />

        <input type="submit" value="添加水印" />

    </form>

</body>

</html>

html

using System;

using System.Collections.Generic;

using System.Drawing;

using System.Linq;

using System.Web;

namespace _06_图片处理

{

    /// <summary>

    /// AddLogo 的摘要说明

    /// </summary>

    public class AddLogo : IHttpHandler

    {

        public void ProcessRequest(HttpContext context)

        {

            context.Response.ContentType = "text/html";

            //01 获取上传图片

            HttpPostedFile pf = context.Request.Files["OrImg"];

            #region 02 添加水印

            //02-01 创建画布

            Bitmap bm = new Bitmap(pf.InputStream);

            //02-02 创建绘图工具

            Graphics gs = Graphics.FromImage(bm);

            //02-03 拿到logo图片

            Bitmap bmLogo = new Bitmap(AppDomain.CurrentDomain.BaseDirectory + "/images/LogoYK.GIF");

            //02-04 开始绘制

            gs.DrawImage(bmLogo,bm.Width-bmLogo.Width,bm.Height-bmLogo.Height,bmLogo.Width,bmLogo.Height);

            #endregion

            #region 03 保存

            //03-01 获取文件扩展名

            string extName = pf.FileName.Substring(pf.FileName.LastIndexOf('.'));

            //03-02 获取文件路径

            string ph = FileHelper.GetFilePath();

            string savePath = ph + extName;

            //03-03 saveAs

            bm.Save(savePath);

            #endregion

            //04 展示

            context.Response.Write("<img src='" + savePath.Substring(savePath.IndexOf("Upload")) + "'/> ");

        }

        public bool IsReusable

        {

            get

            {

                return false;

            }

        }

    }

}

AddLogo.ashx

1.3 运行效果

2 验证码

2.1 ashx页面

using System;

using System.Collections.Generic;

using System.Drawing;

using System.Linq;

using System.Web;

using System.Drawing.Imaging;

namespace _06_图片处理

{

    /// <summary>

    /// ValidateCode 的摘要说明

    /// </summary>

    public class ValidateCode : IHttpHandler

    {

        public void ProcessRequest(HttpContext context)

        {

            //01 验证码是图片,所以修改Type

            context.Response.ContentType = "image/jpeg";

            //02 创建画布

            Bitmap bm = new Bitmap(,);

            //03 创建绘图工具

            Graphics g =   Graphics.FromImage(bm);

            //03-01 设置背景色

            g.Clear(Color.Green);

            //04 准备绘制

            string strArry = "abcdefghijklmnopqrstuvwxyz0123456789";

            string vCode = string.Empty;

            Random r = new Random ();

            for (int i = ; i < ; i++)

            {

                vCode += strArry[r.Next(strArry.Length)];

            }

            //05 开始绘制

            g.DrawString(vCode,new Font (new FontFamily("宋体"),),new SolidBrush(Color.Red),,);

            //06 保存

            bm.Save(context.Response.OutputStream,ImageFormat.Jpeg);

            //context.Response.Write("Hello World");

        }

        public bool IsReusable

        {

            get

            {

                return false;

            }

        }

    }

}

ashx

2.2 HTML页面

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>

    <script src="Script/jquery-1.7.1.min.js"></script>

    <title></title>

    <script>

        $(function () {

            $("#changeCode").click(function () {

                $('#validateCode').attr("src",  $('#validateCode').attr("src")+'1');

            });

        })

    </script>

</head>

<body>

    <img id="validateCode" src="ValidateCode.ashx?1"/>

    <a href="#" id="changeCode">看不清,换一张</a>

</body>

</html>

html

2.3 效果图

3 缩略图

3.1 HTML页面和ashx代码

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>

    <title></title>

</head>

<body>

    <form method="post" action="SmallImag.ashx" enctype="multipart/form-data">

        <input type="file" name="OrImg"/>

        <input type="submit" value="制作缩略图" />

    </form>

</body>

</html>

html

using System;

using System.Collections.Generic;

using System.Drawing;

using System.Linq;

using System.Web;

namespace _06_图片处理

{

    /// <summary>

    /// SmallImag 的摘要说明

    /// </summary>

    public class SmallImag : IHttpHandler

    {

        public void ProcessRequest(HttpContext context)

        {

            context.Response.ContentType = "text/html";

            //01 获取上传对象

            HttpPostedFile hf = context.Request.Files["OrImg"];

            //01-01 获取文件名称和后缀名

            string name = hf.FileName;

            string extName = hf.FileName.Substring(hf.FileName.IndexOf('.'));

            //01-02 获取文件路径 和 相对路径

            string path = FileHelper.GetFilePath();

            string showPath = path.Substring(path.IndexOf("Upload"));

            //02 保存原图片

            hf.SaveAs(path+extName);

            #region 03 绘制缩略后的小图

            //03-00 规定缩放比例

            float scale = 0.3f;

            //03-01 获取原图片

            Bitmap bmBig = new Bitmap(hf.InputStream);

            //03-02 创建画布

            Bitmap bm = new Bitmap((int)(bmBig.Width * scale),(int)(bmBig.Height * scale));

            //03-03 获取绘制工具

            Graphics g = Graphics.FromImage(bm);

            //03-04 开始绘制

            g.DrawImage(bmBig, , , (bmBig.Width * scale), (bmBig.Height * scale));

            #endregion

            //04 保存缩略图

            bm.Save(path +"_small"+ extName);

            //05 展示缩略图

            context.Response.Write("<img src='"+showPath+"_small"+extName+"'/>");

        }

        public bool IsReusable

        {

            get

            {

                return false;

            }

        }

    }

}

SmallImag.ashx

3.2 效果图

码农公寓

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