封装的一些实现图片水印与图片自动结合缩放的类

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.Drawing;
namespace WebHelper
{
   /**//// <summary>
  /// ImageHelper 的摘要说明
 /// </summary>
 public class ImageHelper
   {
     public ImageHelper()
       {
           //
           // TODO: 在此处添加构造函数逻辑
          //
       }
       Image水印#region Image水印
       /**//// <summary>
       /// 写入图像水印
       /// </summary>
       /// <param name="str">水印字符串</param>
       /// <param name="filePath">原图片位置</param>
       /// <param name="savePath">水印加入后的位置</param>
       /// <returns></returns>
        public  string CreateBackImage(System.Web.UI.Page pageCurrent, string str, string filePath, string savePath, int x, int y)
        {
           System.Drawing.Image img = System.Drawing.Image.FromFile(pageCurrent.MapPath(filePath));
            //创建图片
           Graphics graphics = Graphics.FromImage(img);
           //指定要绘制的面积
            graphics.DrawImage(img, 0, 0, img.Width, img.Height);
           //定义字段和画笔
           Font font = new Font("黑体", 16);
           Brush brush = new SolidBrush(Color.Yellow);
           graphics.DrawString(str, font, brush, x, y);
           //保存并输出图片
           img.Save(pageCurrent.MapPath(savePath), System.Drawing.Imaging.ImageFormat.Jpeg);
            return savePath;

       }
        #endregion
        Image自动缩小#region Image自动缩小
        /**//// <summary>
        /// 缩小图片到指定的大小
        /// </summary>
        /// <param name="strOldPic">
        /// 原图片的位置
        /// </param>
        /// <param name="strNewPic">
        /// 缩小后的图片位置
        /// </param>
        /// <param name="intWidth">
       /// 宽度
       /// </param>
        /// <param name="intHeight">
        /// 高度
        /// </param>
        public void SmallPic(string strOldPic, string strNewPic, int intWidth, int intHeight)
        {

            System.Drawing.Bitmap objPic, objNewPic;
            try
            {
                objPic = new System.Drawing.Bitmap(strOldPic);
                objNewPic = new System.Drawing.Bitmap(objPic, intWidth, intHeight);
               objNewPic.Save(strNewPic);
            }
            catch (Exception exp) { throw exp; }
           finally
           {
               objPic = null;
               objNewPic = null;
            }
        }

        public void SmallPic(string strOldPic, string strNewPic, int intWidth)
        {
           System.Drawing.Bitmap objPic, objNewPic;
           try
           {
               objPic = new System.Drawing.Bitmap(strOldPic);
               int intHeight = Convert.ToInt32(((intWidth * 1.0) / (objPic.Width * 1.0)) * objPic.Height);
              objNewPic = new System.Drawing.Bitmap(objPic, intWidth, intHeight);
              objNewPic.Save(strNewPic, objPic.RawFormat);
           }
           catch (Exception exp) { throw exp; }
           finally
           {
               objPic = null;
               objNewPic = null;
            }
        }

      //public void SmallPic(string strOldPic, string strNewPic, int intHeight)
       //{
       //    System.Drawing.Bitmap objPic, objNewPic;
       //    try
       //    {
       //        objPic = new System.Drawing.Bitmap(strOldPic);
       //        int intWidth = Convert.ToInt32(((intHeight * 1.0) / objPic.Height) * objPic.Width);
       //        objNewPic = new System.Drawing.Bitmap(objPic, intWidth, intHeight);
       //        objNewPic.Save(strNewPic, objPic.RawFormat);
       //    }
       //    catch (Exception exp) { throw exp; }
       //    finally
       //    {
       //        objPic = null;
       //        objNewPic = null;
       //    }
       //}
       #endregion

   }
}

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