IO流操作-图片操作（二）

一，选取一张图片



       var open = new OpenFileDialog();

            open.Filter = "图片|*.jpg";

            open.ShowDialog();

            var filepath = open.FileName;

（1）将图片转成流，流的方式生成图片

//第一中方法，先转成流

            FileStream file=new FileStream(filepath,FileMode.Open);

            //创建一个file.length大小的数组控件

            byte[] bt= new byte[file.Length];

             file.Read(bt, 0, bt.Length);

             file.Close();
             //创建内存流

            MemoryStream mstream=new MemoryStream(bt);

            System.Drawing.Image image = System.Drawing.Image.FromStream(mstream);

            var imgPath = "../../IMG/2015.png";

            image.Save(imgPath, ImageFormat.Png);

（二）直接读取



  System.Drawing.Image image = System.Drawing.Image.FromFile(filepath);

            var imgPath = "../../IMG/2015.png";

（3）转成位图进行存储



    Bitmap bi=new Bitmap(filepath);

            var imgPath = "../../IMG/2015.png";

            bi.Save(imgPath);

（4）先转成流，在使用位图进行读取



 FileStream file = new FileStream(filepath, FileMode.Open);

            //创建一个file.length大小的数组控件

            byte[] bt = new byte[file.Length];

            file.Read(bt, 0, bt.Length);

            file.Close();

            //把流转换成内存流

            MemoryStream ms=new MemoryStream(bt);

            Bitmap bi = new Bitmap(ms);

            var imgPath = "../../IMG/2016.png";

            bi.Save(imgPath,ImageFormat.Png);