asp.net压缩图片怎么保持纵横比？
这个代码是网上copy的，选择了cut这个，但是压缩出来的图片会变形，因为一些原图有一些宽一点，有一些就正方形，宽的那些会变形，而正方形的不会。。还有更好的代码么
/// <summary>
/// 生成缩略图
/// </summary>
/// <param name="originalImagePath">源图路径（物理路径）</param>
/// <param name="thumbnailPath">缩略图路径（物理路径）</param>
/// <param name="width">缩略图宽度</param>
/// <param name="height">缩略图高度</param>
/// <param name="mode">生成缩略图的方式</param>
public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)
{
System.Drawing.Image originalImage = System.Drawing.Image.FromFile(originalImagePath);
int towidth = width;
int toheight = height;
int x = 0;
int y = 0;
int ow = originalImage.Width;
int oh = originalImage.Height;
switch (mode)
{
case "HW"://指定高宽缩放（可能变形）
break;
case "W"://指定宽，高按比例
toheight = originalImage.Height * width / originalImage.Width;
break;
case "H"://指定高，宽按比例
towidth = originalImage.Width * height / originalImage.Height;
break;
case "Cut"://指定高宽裁减（不变形）
if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
{
oh = originalImage.Height;
ow = originalImage.Height * towidth / toheight;
y = 0;
x = (originalImage.Width - ow) / 2;
}
else
{
ow = originalImage.Width;
oh = originalImage.Width * height / towidth;
x = 0;
y = (originalImage.Height - oh) / 2;
}
break;
default:
break;
}
//新建一个bmp图片
System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight);
//新建一个画板
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);
//设置高质量插值法
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
//设置高质量,低速度呈现平滑程度
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//清空画布并以透明背景色填充
g.Clear(System.Drawing.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 System.Drawing.Rectangle(0, 0, towidth, toheight),
new System.Drawing.Rectangle(x, y, ow, oh),
System.Drawing.GraphicsUnit.Pixel);
try
{
//以jpg格式保存缩略图
bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
}
catch (System.Exception e)
{
throw e;
}
finally
{
originalImage.Dispose();
bitmap.Dispose();
g.Dispose();
}
}
--------------------编程问答-------------------- 图片要等比例,压缩 --------------------编程问答-------------------- 图片处理 --------------------编程问答--------------------
--------------------编程问答-------------------- 从图片的中心位置 开始算 图片的宽度和高度 --------------------编程问答--------------------
public enum ZoomMode
{
Fixed,
GeometricProportion,
Cut
}
public static void SaveThumbnail(Stream sr, string savePath, int width, int height, ZoomMode zoomMode)
{
using (Image originalImg = Image.FromStream(sr))
{
Size size = originalImg.Size;
switch (zoomMode)
{
case ZoomMode.GeometricProportion:
float scale = Math.Min((float)width / size.Width, (float)height / size.Height);
size = new Size((int)(scale * size.Width), (int)(scale * size.Height));
break;
case ZoomMode.Fixed:
size = new Size(width, height);
break;
case ZoomMode.Cut:
float newScale = (float)width / height;
if (size.Width < size.Height * newScale)
{
size = new Size(size.Width, Convert.ToInt32(size.Width / newScale));
}
else
{
size = new Size(Convert.ToInt32(size.Height * newScale), size.Height);
}
break;
}
Bitmap bmp;
if (zoomMode == ZoomMode.Cut)
bmp = new Bitmap(width, height);
else
bmp = new Bitmap(size.Width, size.Height);
using (bmp)
using (Graphics g = Graphics.FromImage(bmp))
{
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
g.Clear(Color.Transparent);
if (zoomMode != ZoomMode.Cut)
g.DrawImage(originalImg, 0, 0, size.Width, size.Height);
else
g.DrawImage(originalImg, new Rectangle(0, 0, width, height), new Rectangle(0, 0, size.Width, size.Height), GraphicsUnit.Pixel);
bmp.Save(savePath, ImageFormat.Jpeg);
}
}
}
这个可以,怎么实现呢 --------------------编程问答-------------------- --------------------编程问答--------------------
我受不了你了，你怎么就能这么强大呢，你是我的偶像啊！！发自内心的佩服！ --------------------编程问答-------------------- 请参考我的最新下载资源。资源整合了所有图片操作功能：包括剪切、缩放和加盖水印文字。 11 点的时候我上传的，估计明天就可以下载。相信这就是你要找的东西。
补充：.NET技术 , ASP.NET
