判斷 iframe 是否加載完成的完美方法（轉）

般來講，咱們判斷 iframe 是否加載完成其實與 判斷 JavaScript 文件是否加載完成 採用的方法很相似：

var iframe = document.createElement("iframe");
iframe.src = "http://www.planabc.net";
if (!/*@cc_on!@*/0) { //if not IE    
    iframe.onload = function(){        
        alert("Local iframe is now loaded.");    
    };
} else {    
    iframe.onreadystatechange = function(){//ie
        if (iframe.readyState == "complete"){            
            alert("Local iframe is now loaded.");
        }
    };
}
document.body.appendChild(iframe);

　最近， Nicholas C. Zakas 文章《Iframes, onload, and document.domain》的評論中 Christopher 提供了一個新的判斷方法（很完美)

var iframe = document.createElement("iframe");
iframe.src = "http://www.planabc.net";
if (iframe.attachEvent){    
    iframe.attachEvent("onload", function(){        
        alert("Local iframe is now loaded.");    
    });
} else {    
    iframe.onload = function(){        
        alert("Local iframe is now loaded.");    
    };
}
document.body.appendChild(iframe);