C#图片旋转

梦里梦外; 2021-07-04 12:27 449阅读 0赞

> **保存图片的时候一定要选择图片保存的格式**

using System;
    using System.Collections.Generic;
    using System.Drawing;
    using System.Drawing.Imaging;
    using System.IO;
    using System.Linq;
    using System.Web;
    using System.Web.UI;
    
    public partial class AS : System.Web.UI.Page
    { 
        protected void Page_Load(object sender, EventArgs e)
        { 
            System.Drawing.Image img = null;
            string fullpath = Server.MapPath("~/content/originimg.jpg");
            //img = RotateImage(System.Drawing.Image.FromStream(postedFile.InputStream));
            img = RotateImage(System.Drawing.Image.FromFile(fullpath));
    
            int Width = img.Width;
            int Height = img.Height;
    
            //设置文件名
            string fileNewName = DateTime.Now.ToString("yyyyMMddHHmmssff") + "_" + System.IO.Path.GetFileName(fullpath);
            //保存文件
            img.Save(Server.MapPath("~/content/" + fileNewName), GetImageFormat(fullpath)); //保存的时候必须添加图片格式，不然图片会很大；
        }
    
        /// <summary> 
        /// 根据图片exif调整方向 
        /// </summary> 
        private Image RotateImage(Image tmpbitmap)
        { 
            try
            { 
                var exif = tmpbitmap.PropertyItems;
                byte orien = 0;
                var item = exif.Where(m => m.Id == 274).ToArray();
                if (item.Length > 0)
                { 
                    orien = item[0].Value[0];
                }
    
                switch (orien)
                { 
                    case 2:
                        tmpbitmap.RotateFlip(RotateFlipType.RotateNoneFlipX); //horizontal flip 
                        break;
                    case 3:
                        tmpbitmap.RotateFlip(RotateFlipType.Rotate180FlipNone); //right-top 
                        break;
                    case 4:
                        tmpbitmap.RotateFlip(RotateFlipType.RotateNoneFlipY); //vertical flip 
                        break;
                    case 5:
                        tmpbitmap.RotateFlip(RotateFlipType.Rotate90FlipX);
                        break;
                    case 6:
                        tmpbitmap.RotateFlip(RotateFlipType.Rotate90FlipNone); //right-top 
                        break;
                    case 7:
                        tmpbitmap.RotateFlip(RotateFlipType.Rotate270FlipX);
                        break;
                    case 8:
                        tmpbitmap.RotateFlip(RotateFlipType.Rotate270FlipNone); //left-bottom 
                        break;
                    default:
                        break;
                }
    
                Bitmap bitmap = new Bitmap(tmpbitmap);
                tmpbitmap.Dispose();
                return (Image) bitmap;
            }
            catch (Exception E)
            { 
                Response.Write("异常:" + E.Message);
                return tmpbitmap;
            }
        }
    
        private ImageFormat GetImageFormat(string path)
        { 
            string extension = Path.GetExtension(path).ToLower();
    
            if (extension.Equals(".jpeg") || extension.Equals(".jpg"))
                return ImageFormat.Jpeg;
            if (extension.Equals(".bmp"))
                return ImageFormat.Bmp;
            if (extension.Equals(".png"))
                return ImageFormat.Png;
            else
                return ImageFormat.Jpeg;
        }
    }

## 如图: ##

![在这里插入图片描述][20200812180958516.png]

[20200812180958516.png]: /images/20210704/a663ab6727ba4e07ba071d8bf3ae2c6c.png