如何檢測圖像在瀏覽器中是否被禁用？

Question

可能重複：
JavaScript: How to find out when images are turned off in browser?

什麼是檢測用戶是否與圖片瀏覽關閉，並添加另一個樣式表頭那麼最簡單的方法是什麼？

是否有一個簡短的JavaScript代碼片段可以做到這一點，並支持瀏覽器？

Answer 1

這是我的解決方案：

<script type="text/javascript"> 
    detectImageEnabledMode({ 
     onDetectImageIsDisabled:function(){ 
      alert('disabled'); 
     }, 
     onDetectImageIsEnabled:function(){ 
      alert('enabled'); 
     } 
    }); 
    function detectImageEnabledMode(options){ 
     /* define disabled/enabled actions */ 
     var actionCounter = 0; 
     var enabledAction = (options.onDetectImageIsEnabled && typeof(options.onDetectImageIsEnabled)=='function')?options.onDetectImageIsEnabled:function(){}; 
     var enaledActionRun = function(){ 
      if(actionCounter) return; 
      actionCounter++; 
      enabledAction(); 
     } 
     var disabledAction = (options.onDetectImageIsDisabled && typeof(options.onDetectImageIsDisabled)=='function')?options.onDetectImageIsDisabled:function(){}; 
     var disabledActionRun = function(){ 
      if(actionCounter) return; 
      actionCounter++; 
      disabledAction(); 
     } 
     /* create image */ 
     var img = new Image(); 
     var currentTime = (new Date()).getTime(); 
     if(navigator.appName.indexOf('Microsoft Internet Explorer') != -1){// ie 
      img.onload = enaledActionRun; 
      img.onabort = enaledActionRun; 
      img.onerror = enaledActionRun; 
      img.src = currentTime+'.'+currentTime+'?time='+currentTime; 
      setTimeout(function(){ 
       disabledActionRun(); 
      }, 0); 
     }else if (navigator.appName.indexOf('Opera') != -1) {// opera 
      img.src = "data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///ywAAAAAAQABAAACAUwAOw=="+'?time='+(new Date()).getTime(); 
      if(img.complete){ 
       enaledActionRun(); 
      }else{ 
       disabledActionRun(); 
      } 
     }else{// other 
      img.src = currentTime+'.'+currentTime+'?time='+currentTime; 
      if(img.complete){ 
       disabledActionRun(); 
      }else{ 
       enaledActionRun(); 
      } 
     } 
    } 
    // tested in: ff 2+, opera 9+, chrome, safari 4+, ie 6+ 
</script> 

Live demo. 唯一的問題 - 即在最低異步：

setTimeout(function(){ 
disabledActionRun(); 
}, 0);