求一js代码 用于在Gridview中显示缩略图 图片较大 要缩小真实大小生成新的小图片

Question

求一js代码 用于在Gridview中显示缩略图 图片较大 要缩小真实大小生成新的小图片

Answer 1

用JQ
$(document).ready(function(){
    $(img).css({width:"100px",height:"100px"});
});

Answer 2

求一js代码
JS办不到,只能服务器端解决生成新图片?
我来给一个类吧!
/**
 * 产生缩阅图
 * @return boolean
 */
public static void buildSmallPic(File inputFile,File outputFile,int outputWidth,int outputHeight,boolean proportion){
try { 
 if (!inputFile.exists()) return; 
             Image img = ImageIO.read(inputFile); 
             Toolkit toolkit = Toolkit.getDefaultToolkit();
             Image srcImage = toolkit.getImage(inputFile.getAbsolutePath()); // 构造Image对象
             int width = -1;
             int height = -1;
             boolean flag = true;
             while (flag) {
                 width = srcImage.getWidth(null); // 得到源图宽
                 height = srcImage.getHeight(null); // 得到源图长
                 if (width > 0 && height > 0) { 
                     flag = false;
                 } else {
                     try {
                         Thread.sleep(10);
                     } catch (Exception e) {
                         e.printStackTrace();
                     }
                 }
             }
             
             //if(width==outputWidth && height==outputHeight) return ;//相等了
             
             //判断图片格式是否正确 
             if (img.getWidth(null) == -1) {
                 System.out.println("can't read,retry!" + "<BR>"); 
                 return; 
             }else{ 
              if (!outputFile.exists()) { 
              outputFile.createNewFile();
              }
              int newWidth; int newHeight; 
              // 判断是否是等比缩放 
                 if (proportion == true) { 
                     // 为等比缩放计算输出的图片宽度及高度 
                     double rate1 = ((double) img.getWidth(null)) / (double) outputWidth + 0.1; 
                     double rate2 = ((double) img.getHeight(null)) / (double) outputHeight + 0.1; 
                     // 根据缩放比率大的进行缩放控制 
                     double rate = rate1 > rate2 ? rate1 : rate2; 
                     newWidth = (int) (((double) img.getWidth(null)) / rate); 
                     newHeight = (int) (((double) img.getHeight(null)) / rate); 
                 } else { 
                     newWidth = outputWidth; // 输出的图片宽度 
                     newHeight = outputHeight; // 输出的图片高度 
                 } 
                 
                 
                 
                 BufferedImage tag = new BufferedImage((int)newWidth, (int) newHeight, BufferedImage.TYPE_INT_RGB); 
                 /*
                 * Image.SCALE_SMOOTH 的缩略算法 生成缩略图片的平滑度的
                 * 优先级比速度高 生成的图片质量比较好 但速度慢
                 */ 
                 Graphics2D g = tag.createGraphics();
                 g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
                 g.drawImage(img.getScaledInstance(newWidth,newHeight,Image.SCALE_SMOOTH),0,0,null);
                 g.dispose();
                 
                 /*质量不高
                 /* FileOutputStream out = new FileOutputStream(outputFile);
                 // JPEGImageEncoder可适用于其他图片类型的转换 
                 JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out); 
                 encoder.encode(tag); 
                 out.close();*/
     
                 // FileOutputStream out = new FileOutputStream(outputFile);
                 // JPEGImageEncoder可适用于其他图片类型的转换 
                 //JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
                 ImageWriter   writer   =   null; 
                 ImageTypeSpecifier   type   =  ImageTypeSpecifier.createFromRenderedImage(tag); 
                 Iterator<ImageWriter>   iter   =   ImageIO.getImageWriters(type,"jpg"); 
                 if(iter.hasNext())   { 
                  writer=(ImageWriter)iter.next(); 
                 } 
                 if(writer ==null)   { 
                    return; 
                 } 
                 IIOImage iioImage = new   IIOImage(tag,   null,   null); 
                 ImageWriteParam   param   =   writer.getDefaultWriteParam(); 
                 param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT); 
                 //设置质量(0.1-1)
              param.setCompressionQuality(1f); 
                 ImageOutputStream   outputStream   =  ImageIO.createImageOutputStream(outputFile);
                 writer.setOutput(outputStream); 
                 writer.write(null,   iioImage,   param); 
                 
                 outputStream.flush();
                 outputStream.close();
             }
        } catch (IOException ex) { 
            ex.printStackTrace(); 
        } 
}