Implement image related operations (redraw, get size, resize, zoom) based on jquery_jquery

This article shares four common jquery image operations for your reference. The specific content is as follows

1. Regarding redrawing the image size, you can implement it on the server side or on the client side through JQuery.

$(window).bind("load", function() {
   // IMAGE RESIZE
   $('#product_cat_list img').each(function() {
     var maxWidth = 120;
     var maxHeight = 120;
     var ratio = 0;
     var width = $(this).width();
     var height = $(this).height();
 
     if(width > maxWidth){
      ratio = maxWidth / width;
      $(this).css("width", maxWidth);
      $(this).css("height", height * ratio);
      height = height * ratio;
     }
     var width = $(this).width();
     var height = $(this).height();
     if(height > maxHeight){
      ratio = maxHeight / height;
      $(this).css("height", maxHeight);
      $(this).css("width", width * ratio);
      width = width * ratio;
     }
   });
   //$("#contentpage img").show();
   // IMAGE RESIZE
});

2. How to get the actual size of the image with jQuery

$(function(){
 var imgSrc = $("#image").attr("src");
 getImageWidth(imgSrc,function(w,h){
 console.log({width:w,height:h});
 });
});

function getImageWidth(url,callback){
 var img = new Image();
 img.src = url;
 
 // 如果图片被缓存，则直接返回缓存数据
 if(img.complete){
   callback(img.width, img.height);
 }else{
      // 完全加载完毕的事件
   img.onload = function(){
 callback(img.width, img.height);
   }
    }
 
}

3. jquery automatically adjusts image size

$(document).ready(function(){
        $('img').each(function() {  
        var maxWidth =500; // 图片最大宽度  
        var maxHeight =500;  // 图片最大高度  
        var ratio = 0; // 缩放比例 
         var width = $(this).width();  // 图片实际宽度  
         var height = $(this).height(); // 图片实际高度   // 检查图片是否超宽  
         if(width > maxWidth){    
         ratio = maxWidth / width;  // 计算缩放比例    
         $(this).css("width", maxWidth); // 设定实际显示宽度    
         height = height * ratio;  // 计算等比例缩放后的高度    
         $(this).css("height", height); // 设定等比例缩放后的高度  
         }   // 检查图片是否超高 
          if(height > maxHeight){    
          ratio = maxHeight / height; // 计算缩放比例   
          $(this).css("height", maxHeight);  // 设定实际显示高度    
          width = width * ratio;  // 计算等比例缩放后的高度    
          $(this).css("width", width);  // 设定等比例缩放后的高度  
          }});
      });

4. Use jQuery to resize images

$(window).bind("load", function() {
  // IMAGE RESIZE
  $('#product_cat_list img').each(function() {
    var maxWidth = 120;
    var maxHeight = 120;
    var ratio = 0;
    var width = $(this).width();
    var height = $(this).height();
 
    if(width > maxWidth){
      ratio = maxWidth / width;
      $(this).css("width", maxWidth);
      $(this).css("height", height * ratio);
      height = height * ratio;
    }
    var width = $(this).width();
    var height = $(this).height();
    if(height > maxHeight){
      ratio = maxHeight / height;
      $(this).css("height", maxHeight);
      $(this).css("width", width * ratio);
      width = width * ratio;
    }
  });
  //$("#contentpage img").show();
  // IMAGE RESIZE
});

The above is the entire content of this article to help you achieve image redrawing, image resizing, image resizing and image scaling. I hope you like it.