生成缩略图代码,Asp.Net代码库,德仔网

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代码分类
【Asp.Net】生成缩略图
作者:Dezai.CN / 发布于2011/7/8/ 782
<div><span style="color: rgb(128,128,128)">///</span><span style="color: rgb(0,128,0)"> </span><span style="color: rgb(128,128,128)"><summary></span><span style="color: rgb(0,128,0)">
 </span><span style="color: rgb(128,128,128)">///</span><span style="color: rgb(0,128,0)"> 生成缩略图
 </span><span style="color: rgb(128,128,128)">///</span><span style="color: rgb(0,128,0)"> </span><span style="color: rgb(128,128,128)"></summary></span><span style="color: rgb(0,128,0)">
 </span><span style="color: rgb(128,128,128)">///</span><span style="color: rgb(0,128,0)"> </span><span style="color: rgb(128,128,128)"><param name="originalImagePath"></span><span style="color: rgb(0,128,0)">源图路径（物理路径）</span><span style="color: rgb(128,128,128)"></param></span><span style="color: rgb(0,128,0)">
 </span><span style="color: rgb(128,128,128)">///</span><span style="color: rgb(0,128,0)"> </span><span style="color: rgb(128,128,128)"><param name="thumbnailPath"></span><span style="color: rgb(0,128,0)">缩略图路径（物理路径）</span><span style="color: rgb(128,128,128)"></param></span><span style="color: rgb(0,128,0)">
 </span><span style="color: rgb(128,128,128)">///</span><span style="color: rgb(0,128,0)"> </span><span style="color: rgb(128,128,128)"><param name="width"></span><span style="color: rgb(0,128,0)">缩略图宽度</span><span style="color: rgb(128,128,128)"></param></span><span style="color: rgb(0,128,0)">
 </span><span style="color: rgb(128,128,128)">///</span><span style="color: rgb(0,128,0)"> </span><span style="color: rgb(128,128,128)"><param name="height"></span><span style="color: rgb(0,128,0)">缩略图高度</span><span style="color: rgb(128,128,128)"></param></span><span style="color: rgb(0,128,0)">
 </span><span style="color: rgb(128,128,128)">///</span><span style="color: rgb(0,128,0)"> </span><span style="color: rgb(128,128,128)"><param name="mode"></span><span style="color: rgb(0,128,0)">生成缩略图的方式</span><span style="color: rgb(128,128,128)"></param></span><span style="color: rgb(0,128,0)"> </span><span style="color: rgb(128,128,128)">
</span><span style="color: rgb(0,0,255)">public</span><span style="color: rgb(0,0,0)"> </span><span style="color: rgb(0,0,255)">static</span><span style="color: rgb(0,0,0)"> </span><span style="color: rgb(0,0,255)">void</span><span style="color: rgb(0,0,0)"> MakeThumbnail(</span><span style="color: rgb(0,0,255)">string</span><span style="color: rgb(0,0,0)"> originalImagePath, </span><span style="color: rgb(0,0,255)">string</span><span style="color: rgb(0,0,0)"> thumbnailPath, </span><span style="color: rgb(0,0,255)">int</span><span style="color: rgb(0,0,0)"> width, </span><span style="color: rgb(0,0,255)">int</span><span style="color: rgb(0,0,0)"> height, </span><span style="color: rgb(0,0,255)">string</span><span style="color: rgb(0,0,0)"> mode)
 {
 Image originalImage </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> Image.FromFile(originalImagePath);

 </span><span style="color: rgb(0,0,255)">int</span><span style="color: rgb(0,0,0)"> towidth </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> width;
 </span><span style="color: rgb(0,0,255)">int</span><span style="color: rgb(0,0,0)"> toheight </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> height;

 </span><span style="color: rgb(0,0,255)">int</span><span style="color: rgb(0,0,0)"> x </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> </span><span style="color: rgb(128,0,128)">0</span><span style="color: rgb(0,0,0)">;
 </span><span style="color: rgb(0,0,255)">int</span><span style="color: rgb(0,0,0)"> y </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> </span><span style="color: rgb(128,0,128)">0</span><span style="color: rgb(0,0,0)">;
 </span><span style="color: rgb(0,0,255)">int</span><span style="color: rgb(0,0,0)"> ow </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> originalImage.Width;
 </span><span style="color: rgb(0,0,255)">int</span><span style="color: rgb(0,0,0)"> oh </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> originalImage.Height;

 </span><span style="color: rgb(0,0,255)">switch</span><span style="color: rgb(0,0,0)"> (mode)
 {
 </span><span style="color: rgb(0,0,255)">case</span><span style="color: rgb(0,0,0)"> </span><span style="color: rgb(128,0,0)">"</span><span style="color: rgb(128,0,0)">HW</span><span style="color: rgb(128,0,0)">"</span><span style="color: rgb(0,0,0)">:</span><span style="color: rgb(0,128,0)">//</span><span style="color: rgb(0,128,0)">指定高宽缩放（可能变形） </span><span style="color: rgb(0,128,0)">
</span><span style="color: rgb(0,0,0)"> </span><span style="color: rgb(0,0,255)">break</span><span style="color: rgb(0,0,0)">;
 </span><span style="color: rgb(0,0,255)">case</span><span style="color: rgb(0,0,0)"> </span><span style="color: rgb(128,0,0)">"</span><span style="color: rgb(128,0,0)">W</span><span style="color: rgb(128,0,0)">"</span><span style="color: rgb(0,0,0)">:</span><span style="color: rgb(0,128,0)">//</span><span style="color: rgb(0,128,0)">指定宽，高按比例 </span><span style="color: rgb(0,128,0)">
</span><span style="color: rgb(0,0,0)"> toheight </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> originalImage.Height </span><span style="color: rgb(0,0,0)">*</span><span style="color: rgb(0,0,0)"> width </span><span style="color: rgb(0,0,0)">/</span><span style="color: rgb(0,0,0)"> originalImage.Width;
 </span><span style="color: rgb(0,0,255)">break</span><span style="color: rgb(0,0,0)">;
 </span><span style="color: rgb(0,0,255)">case</span><span style="color: rgb(0,0,0)"> </span><span style="color: rgb(128,0,0)">"</span><span style="color: rgb(128,0,0)">H</span><span style="color: rgb(128,0,0)">"</span><span style="color: rgb(0,0,0)">:</span><span style="color: rgb(0,128,0)">//</span><span style="color: rgb(0,128,0)">指定高，宽按比例</span><span style="color: rgb(0,128,0)">
</span><span style="color: rgb(0,0,0)"> towidth </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> originalImage.Width </span><span style="color: rgb(0,0,0)">*</span><span style="color: rgb(0,0,0)"> height </span><span style="color: rgb(0,0,0)">/</span><span style="color: rgb(0,0,0)"> originalImage.Height;
 </span><span style="color: rgb(0,0,255)">break</span><span style="color: rgb(0,0,0)">;
 </span><span style="color: rgb(0,0,255)">case</span><span style="color: rgb(0,0,0)"> </span><span style="color: rgb(128,0,0)">"</span><span style="color: rgb(128,0,0)">Cut</span><span style="color: rgb(128,0,0)">"</span><span style="color: rgb(0,0,0)">:</span><span style="color: rgb(0,128,0)">//</span><span style="color: rgb(0,128,0)">指定高宽裁减（不变形） </span><span style="color: rgb(0,128,0)">
</span><span style="color: rgb(0,0,0)"> </span><span style="color: rgb(0,0,255)">if</span><span style="color: rgb(0,0,0)"> ((</span><span style="color: rgb(0,0,255)">double</span><span style="color: rgb(0,0,0)">)originalImage.Width </span><span style="color: rgb(0,0,0)">/</span><span style="color: rgb(0,0,0)"> (</span><span style="color: rgb(0,0,255)">double</span><span style="color: rgb(0,0,0)">)originalImage.Height </span><span style="color: rgb(0,0,0)">></span><span style="color: rgb(0,0,0)"> (</span><span style="color: rgb(0,0,255)">double</span><span style="color: rgb(0,0,0)">)towidth </span><span style="color: rgb(0,0,0)">/</span><span style="color: rgb(0,0,0)"> (</span><span style="color: rgb(0,0,255)">double</span><span style="color: rgb(0,0,0)">)toheight)
 {
 oh </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> originalImage.Height;
 ow </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> originalImage.Height </span><span style="color: rgb(0,0,0)">*</span><span style="color: rgb(0,0,0)"> towidth </span><span style="color: rgb(0,0,0)">/</span><span style="color: rgb(0,0,0)"> toheight;
 y </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> </span><span style="color: rgb(128,0,128)">0</span><span style="color: rgb(0,0,0)">;
 x </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> (originalImage.Width </span><span style="color: rgb(0,0,0)">-</span><span style="color: rgb(0,0,0)"> ow) </span><span style="color: rgb(0,0,0)">/</span><span style="color: rgb(0,0,0)"> </span><span style="color: rgb(128,0,128)">2</span><span style="color: rgb(0,0,0)">;
 }
 </span><span style="color: rgb(0,0,255)">else</span><span style="color: rgb(0,0,0)">
 {
 ow </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> originalImage.Width;
 oh </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> originalImage.Width </span><span style="color: rgb(0,0,0)">*</span><span style="color: rgb(0,0,0)"> height </span><span style="color: rgb(0,0,0)">/</span><span style="color: rgb(0,0,0)"> towidth;
 x </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> </span><span style="color: rgb(128,0,128)">0</span><span style="color: rgb(0,0,0)">;
 y </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> (originalImage.Height </span><span style="color: rgb(0,0,0)">-</span><span style="color: rgb(0,0,0)"> oh) </span><span style="color: rgb(0,0,0)">/</span><span style="color: rgb(0,0,0)"> </span><span style="color: rgb(128,0,128)">2</span><span style="color: rgb(0,0,0)">;
 }
 </span><span style="color: rgb(0,0,255)">break</span><span style="color: rgb(0,0,0)">;
 </span><span style="color: rgb(0,0,255)">default</span><span style="color: rgb(0,0,0)">:
 </span><span style="color: rgb(0,0,255)">break</span><span style="color: rgb(0,0,0)">;
 }

 </span><span style="color: rgb(0,128,0)">//</span><span style="color: rgb(0,128,0)">新建一个bmp图片</span><span style="color: rgb(0,128,0)">
</span><span style="color: rgb(0,0,0)"> Image bitmap </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> </span><span style="color: rgb(0,0,255)">new</span><span style="color: rgb(0,0,0)"> System.Drawing.Bitmap(towidth, toheight);

 </span><span style="color: rgb(0,128,0)">//</span><span style="color: rgb(0,128,0)">新建一个画板</span><span style="color: rgb(0,128,0)">
</span><span style="color: rgb(0,0,0)"> Graphics g </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> System.Drawing.Graphics.FromImage(bitmap);

 </span><span style="color: rgb(0,128,0)">//</span><span style="color: rgb(0,128,0)">设置高质量插值法</span><span style="color: rgb(0,128,0)">
</span><span style="color: rgb(0,0,0)"> g.InterpolationMode </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> System.Drawing.Drawing2D.InterpolationMode.High;

 </span><span style="color: rgb(0,128,0)">//</span><span style="color: rgb(0,128,0)">设置高质量,低速度呈现平滑程度</span><span style="color: rgb(0,128,0)">
</span><span style="color: rgb(0,0,0)"> g.SmoothingMode </span><span style="color: rgb(0,0,0)">=</span><span style="color: rgb(0,0,0)"> System.Drawing.Drawing2D.SmoothingMode.HighQuality;

 </span><span style="color: rgb(0,128,0)">//</span><span style="color: rgb(0,128,0)">清空画布并以透明背景色填充</span><span style="color: rgb(0,128,0)">
</span><span style="color: rgb(0,0,0)"> g.Clear(Color.Transparent);

 </span><span style="color: rgb(0,128,0)">//</span><span style="color: rgb(0,128,0)">在指定位置并且按指定大小绘制原图片的指定部分</span><span style="color: rgb(0,128,0)">
</span><span style="color: rgb(0,0,0)"> g.DrawImage(originalImage, </span><span style="color: rgb(0,0,255)">new</span><span style="color: rgb(0,0,0)"> Rectangle(</span><span style="color: rgb(128,0,128)">0</span><span style="color: rgb(0,0,0)">, </span><span style="color: rgb(128,0,128)">0</span><span style="color: rgb(0,0,0)">, towidth, toheight),
 </span><span style="color: rgb(0,0,255)">new</span><span style="color: rgb(0,0,0)"> Rectangle(x, y, ow, oh),
 GraphicsUnit.Pixel);

 </span><span style="color: rgb(0,0,255)">try</span><span style="color: rgb(0,0,0)">
 {
 </span><span style="color: rgb(0,128,0)">//</span><span style="color: rgb(0,128,0)">以jpg格式保存缩略图</span><span style="color: rgb(0,128,0)">
</span><span style="color: rgb(0,0,0)"> bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
 }
 </span><span style="color: rgb(0,0,255)">catch</span><span style="color: rgb(0,0,0)"> (System.Exception e)
 {
 </span><span style="color: rgb(0,0,255)">throw</span><span style="color: rgb(0,0,0)"> e;
 }
 </span><span style="color: rgb(0,0,255)">finally</span><span style="color: rgb(0,0,0)">
 {
 originalImage.Dispose();
 bitmap.Dispose();
 g.Dispose();
 }
 }</span></div>
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