上传 添加图片水印 添加文字水印 图片剪裁 压缩图片 返回文件类型

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Drawing.Imaging;
using System.Drawing;
using System.IO;

/// <summary>
///Method 的摘要说明
/// </summary>
public class Method
{
 public Method()
 {
  //
  //TODO: 在此处添加构造函数逻辑
  //
 }

    /// <summary>
    /// 添加图片水印
    /// </summary>
    /// <param name="image1">/此处添加添加被加水印的图片</param>
    /// <param name="image2">此外添加添加水印图片</param>
    /// <param name="num"></param>
    /// <param name="savepath"></param>
    private void DrawImage(string image1,string image2,int num,string savepath)
    {
        System.Drawing.Image image = System.Drawing.Image.FromFile(image1);          //此处添加添加被加水印的图片
        System.Drawing.Image copyImage = System.Drawing.Image.FromFile(image2);   //此外添加添加水印图片

        ImageAttributes attributes = new ImageAttributes();

        float alpha = num / 255.0f;                                               //这里来设置透明度(只修改此处就可以了)
        float[][] colorMatrixElements = {
           new float[] {1.0f, 0.0f, 0.0f, 0.0f, 0.0f},
           new float[] {0.0f, 1.0f, 0.0f, 0.0f, 0.0f},
           new float[] {0.0f, 0.0f, 1.0f, 0.0f, 0.0f},
           new float[] {0.0f, 0.0f, 0.0f, alpha, 0.0f},
           new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}
        };
        ColorMatrix colorMatrix = new ColorMatrix(colorMatrixElements);
        ///设置颜色调整矩阵
        attributes.SetColorMatrix(colorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);

        Graphics g = Graphics.FromImage(image);
        g.DrawImage(copyImage, new Rectangle(image.Width - copyImage.Width, image.Height - copyImage.Height, copyImage.Width, copyImage.Height), 0, 0, copyImage.Width, copyImage.Height, GraphicsUnit.Pixel, attributes);     //合成图片
        g.Dispose();                 //销毁对象
        image.Save(savepath);       //保存合成的图片
    }
    /// <summary>
    /// 图片剪裁
    /// </summary>
    /// <param name="imagepth">图片路径</param>
    /// <param name="savepath">保存路径</param>
    /// <param name="x">起始的X坐标</param>
    /// <param name="y">起始的Y坐标</param>
    /// <param name="newwidth">新图片的宽度</param>
    /// <param name="newheith">新图片的高度</param>
    protected void CutPic(string imagepth, string savepath, int x, int y, int newwidth, int newheith)
    {

        //int x = 0, y = 0;      //剪裁的照片(起始坐标)
        //int newwidth = 2;    //图片的宽度(新图片)
        //int newheith = 50;     //图片的高度(新图片)
        //以上是设置的参数

        ///以下为执行剪裁图片的操作Server.MapPath("UploadImage") + "/main_01.gif"
        System.Drawing.Image newImage = System.Drawing.Image.FromFile(imagepth);
        ///加载
        Bitmap b = new Bitmap(newwidth, newheith);
        Graphics g = Graphics.FromImage(b);

 

        GraphicsUnit units = GraphicsUnit.Pixel;
        g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBilinear;
        g.DrawImage(newImage, new Rectangle(0, 0, b.Width, b.Height), x, y, newwidth, newheith, units);
        ///保存剪裁后的图片Server.MapPath("UploadImage") + "/cut.jpg"
        b.Save(savepath);

 

    }
    /// <summary>
    /// 添加文字水印
    /// </summary>
    /// <param name="wordstring">水印文字</param>
    /// <param name="savepath">保存路径</param>
    /// <param name="inputstream">FileUpload.PostedFile.InputStream</param>
    private void DrawWord(string wordstring,string savepath,Stream inputstream)
    {
        //FileUpload2.PostedFile.InputStream
        System.Drawing.Image img = Bitmap.FromStream(inputstream);    //在Cs后台代码中可以直接写 FileUpload2.PostedFile.InputStream

        img = img.GetThumbnailImage(img.Size.Width / 1, img.Size.Height / 1, null, System.IntPtr.Zero);

        Bitmap output = new Bitmap(img);
        Graphics g = Graphics.FromImage(output);
        g.DrawString(wordstring, new Font("Courier New", 20), new SolidBrush(Color.Gray), 0, img.Size.Height - 30);
        //Server.MapPath("UploadImage") + "/text.jpg"
        output.Save(savepath);
    }
    /// <summary>
    /// 压缩图片
    /// </summary>
    /// <param name="InputStream">FileUpload.PostedFile.InputStream</param>
    /// <param name="Ziprate">压缩率</param>
    /// <param name="savepath">保存路径</param>
    private void Zip(Stream InputStream,int Ziprate,string savepath)
    {

        //int rate = Convert.ToInt32(DropDownList1.SelectedValue);
        //FileUpload1.PostedFile.InputStream
        System.Drawing.Image img = Bitmap.FromStream(InputStream);

        img = img.GetThumbnailImage(img.Size.Width / Ziprate, img.Size.Height / Ziprate, null, System.IntPtr.Zero);

        Graphics g = Graphics.FromImage(img);         //定一个graphics实例，参数为要改变分辨率的图片  
        // g.DrawImage(img, 0, 0, img.Size.Width / rate, img.Size.Height / rate);//将要改变分辨率的图片画到新的位图变量里  

         //Server.MapPath("UploadImage") + "/text.jpg"
        img.Save(savepath);
    }
    ///返回文件类型
    /// FileUpload4.PostedFile.ContentType.ToString().Substring(FileUpload4.PostedFile.ContentType.ToString().LastIndexOf("/")+1)

}