public ImageSizeType(int width, int height, bool markSuare, bool cut, string extname, ImageMakeMode type,ImageWaterMark watermark)
{
this.width = width;
this.height = height;
this.markSuare = markSuare;
this.cut = cut;
this.extname = extname;
this.type = type;
this.watermark = watermark;
}
/// <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, ImageMakeMode mode,ImageWaterMark watermark)
{
Image originalImage = Image.FromFile(originalImagePath);
Image bitmap =
MakeThumbnail(width, height, mode, originalImage, watermark);
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();
}
}
public static Image MakeThumbnail(int width, int height, ImageMakeMode mode, Image originalImage,ImageWaterMark watermark)
{
Image bitmap;
Graphics g;
int towidth = width;
int toheight = height;
int x = 0;
int y = 0;
int ow = originalImage.Width;
int oh = originalImage.Height;
switch (mode)
{
case ImageMakeMode.HW://指定高宽缩放（可能变形）
break;
case ImageMakeMode.W://指定宽，高按比例
toheight = originalImage.Height * width / originalImage.Width;
break;
case ImageMakeMode.WButOnlyShrink://指定宽，高按比例，但仅缩小，小于高度的图片不会放大
if (originalImage.Width <= towidth)
{
towidth = originalImage.Width;
toheight = originalImage.Height;
}
else
{
toheight = originalImage.Height * width / originalImage.Width;
}
break;
case ImageMakeMode.H://指定高，宽按比例
towidth = originalImage.Width * height / originalImage.Height;
break;
case ImageMakeMode.HButOnlyShrink://指定高，宽按比例，但仅缩小，小于高度的图片不会被放大
if (originalImage.Height <= toheight)
{
towidth = originalImage.Width;
toheight = originalImage.Height;
}
else
{
towidth = originalImage.Width * height / originalImage.Height;
}
break;
case ImageMakeMode.Cut://指定高宽裁减
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;
case ImageMakeMode.CutA://指定高宽裁减（不变形）自定义
if (ow <= towidth && oh <= toheight)
{
x = -(towidth - ow) / 2;
y = -(toheight - oh) / 2;
ow = towidth;
oh = toheight;
}
else
{
if (ow > oh)//宽大于高
{
x = 0;
y = -(ow - oh) / 2;
oh = ow;
}
else//高大于宽
{
y = 0;
x = -(oh - ow) / 2;
ow = oh;
}
}
break;
default:
break;
}
//新建一个bmp图片
bitmap = new System.Drawing.Bitmap(towidth, toheight);
//新建一个画板
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;
//清空画布并以白色背景色填充
g.Clear(Color.White);
//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, towidth, toheight),
new Rectangle(x, y, ow, oh),
GraphicsUnit.Pixel);
//放置水印
if (watermark != null)
{
if (watermark.WaterPicOn)
{
Image waterimg = null;
try
{
waterimg = Image.FromFile(watermark.WaterPicPath);
}
catch { }
if (waterimg != null)
{
g.DrawImage(waterimg,
new Rectangle(
bitmap.Width-waterimg.Width-watermark.WaterPicMarginRight,
bitmap.Height-waterimg.Height-watermark.WaterPicMarginBottom,
waterimg.Width,
waterimg.Height),
0,
0,
waterimg.Width,
waterimg.Height,
GraphicsUnit.Pixel
);
}
}
}
g.Dispose();
return bitmap;
}