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[ASP.net教程]C# 剪裁图片并保存


最近需要将一张图片上传并按指定位置剪裁,后来在网上找了一个剪裁图片的插件,但是只有前台没有后端,然后我各种百度,并最终完成,特此写一篇博客略表纪念。

前台我就不说了,用的cropper插件,有兴趣的自己去百度找找吧。jQuery之家 有这个插件。

下面是代码:

    HttpPostedFile file = context.Request.Files["avatar_file"];    string datasize = context.Request.Params["avatar_data"];    //{"x":30.003846153846148,"y":16.715384615384625,"height":300.8,"width":300.8,"rotate":0}   剪裁之后参数    JavaScriptSerializer jss = new JavaScriptSerializer();    ImgSize imagesize = jss.Deserialize<ImgSize>(datasize);    byte[] FileByte = SetFileToByteArray(file);//图片数组    string strtExtension = System.IO.Path.GetExtension(file.FileName);//图片格式    MemoryStream ms1 = new MemoryStream(FileByte);    Bitmap sBitmap = (Bitmap)Image.FromStream(ms1);    Rectangle section = new Rectangle(new Point(imagesize.ToInt(imagesize.x), imagesize.ToInt(imagesize.y)), new Size(imagesize.ToInt(imagesize.width), imagesize.ToInt(imagesize.height)));    Bitmap CroppedImage = MakeThumbnailImage(sBitmap, section.Width, section.Height, section.Width, section.Height, section.X, section.Y);

 

上面代码中用到我自己创建了一个ImgSize类,代码如下:

  class ImgSize  {    //{"x":30.003846153846148,"y":16.715384615384625,"height":300.8,"width":300.8,"rotate":0}    public double x { get; set; }    public double y { get; set; }    public double width { get; set; }    public double height { get; set; }    public int rotate { get; set; }    public int ToInt(double doubleValue)    {      return Convert.ToInt32(doubleValue);    }  }

上面代码中使用到的几个方法:

文件转化:

  /// <summary>  /// 将From表单file文件转化为byte数组  /// </summary>  /// <param name="File">from提交文件流</param>  /// <returns></returns>  private byte[] SetFileToByteArray(HttpPostedFile File)  {    Stream stream = File.InputStream;    byte[] AyyayByte = new byte[File.ContentLength];    stream.Read(AyyayByte, 0, File.ContentLength);    stream.Close();    return AyyayByte;  }

核心剪裁方法:

  /// <summary>  /// 裁剪图片并保存  /// </summary>  /// <param name="Image">图片信息</param>  /// <param name="maxWidth">缩略图宽度</param>  /// <param name="maxHeight">缩略图高度</param>  /// <param name="cropWidth">裁剪宽度</param>  /// <param name="cropHeight">裁剪高度</param>  /// <param name="X">X轴</param>  /// <param name="Y">Y轴</param>  public static Bitmap MakeThumbnailImage(Image originalImage, int maxWidth, int maxHeight, int cropWidth, int cropHeight, int X, int Y)  {    Bitmap b = new Bitmap(cropWidth, cropHeight);    try    {      using (Graphics g = Graphics.FromImage(b))      {        //清空画布并以透明背景色填充        g.Clear(Color.Transparent);        //在指定位置并且按指定大小绘制原图片的指定部分        g.DrawImage(originalImage, new Rectangle(0, 0, cropWidth, cropHeight), X, Y, cropWidth, cropHeight, GraphicsUnit.Pixel);        Image displayImage = new Bitmap(b, maxWidth, maxHeight);        displayImage.Save("E:\\cutimg.jpg", System.Drawing.Imaging.ImageFormat.Jpeg);        Bitmap bit = new Bitmap(b, maxWidth, maxHeight);        return bit;      }    }    catch (System.Exception e)    {      throw e;    }    finally    {      originalImage.Dispose();      b.Dispose();    }  }

最后的结果是把存到了E盘根目录下面