Javascript for循环中HTML集合的事件侦听器和闭包
代码是Javascript for循环中HTML集合的事件侦听器和闭包,javascript,for-loop,closures,htmlcollection,Javascript,For Loop,Closures,Htmlcollection,代码是 //Logic which works when the desired element is clicked function changeArtistPhotoAndBio(prop) { var artistPhoto = document.getElementsByClassName("artist-photo")[0]; var artistBio = document.getElementsByClassName("artist-bio")[0];
//Logic which works when the desired element is clicked
function changeArtistPhotoAndBio(prop) {
var artistPhoto = document.getElementsByClassName("artist-photo")[0];
var artistBio = document.getElementsByClassName("artist-bio")[0];
var i = prop.getAttribute("src").indexOf(".jpg");
var photoName = prop.getAttribute("src").slice (0, i);
artistPhoto.style.background="url(" + photoName + "-large.jpg";
console.log("it happened");
};
//Setting listeners for the click event in the loop
var artists = document.getElementsByClassName("gallery")[0].getElementsByTagName("img");
for (var i = 0; i < artists.length; i++) {
artists[i].addEventListener("click", changeArtistPhotoAndBio(artists[i]));
}
并且click函数的事件处理程序不起作用。我尝试过在闭包中隔离处理程序,如下所示:
for (var i = 0; i < artists.length; i++) {(function(i) {
artists[i].addEventListener("click", changeArtistPhotoAndBio(artists[i]));
}(i))
}
for(var i=0;i
但是输出仍然是一样的。因此有两个问题:
1) 为什么控制台输出包含七个处理程序调用的结果?如果我没有调用函数,只是将其设置为处理程序
2) 如何在HTML集合的“for”循环中设置处理程序
var artists = document.getElementsByClassName("gallery")[0].getElementsByTagName("img");
for (var i = 0; i < artists.length; i++) {
artists[i].addEventListener("click", function(index) {
return function() {
//You can use index for the current clicked item index
// console.log(index);
var artistPhoto = document.getElementsByClassName("artist-photo")[0];
var artistBio = document.getElementsByClassName("artist-bio")[0];
var i = this.getAttribute("src").indexOf(".jpg");
var photoName = this.getAttribute("src").slice (0, i);
artistPhoto.style.background="url(" + photoName + "-large.jpg";
console.log("it happened");
}
}(i));
}
var artists=document.getElementsByClassName(“画廊”)[0].getElementsByTagName(“img”);
for(var i=0;i
$('body*')
选择body中的所有元素。它应该是例如changeArtistPhotoAndBio.bind({},artists[i])
并且您缺少结束父项。这里是:url(“+photoName+”-large.jpg”
感谢您的回答和注意括号。但是我已经尝试绑定函数,但没有效果(即处理程序不工作).当然,我试过你的例子,但仍然不起作用。你的意思是处理程序没有被触发?你应该提供复制你的问题的最低限度的示例,例如在JSFIDDLOk上,这里是小提琴:我已经通过它进行了测试,无论出于什么原因,当我查找“img”元素时,它都不起作用,但在查找“li”时确实起作用元素。因为使用了artists[i]。添加了EventListener(“单击”,changeArtistPhotoAndBio(artists[i]);
您使用的返回函数changeArtistPhotoAndBio
的处理程序结果,在您的情况下,该函数是未定义的
(此函数不返回任何内容)。如果要将函数本身用作处理程序,则必须使用它的引用,或者可以将其包装在匿名函数中。基本上,使用anyFunction()
调用函数anyFunction
var artists = document.getElementsByClassName("gallery")[0].getElementsByTagName("img");
for (var i = 0; i < artists.length; i++) {
artists[i].addEventListener("click", function(index) {
return function() {
//You can use index for the current clicked item index
// console.log(index);
var artistPhoto = document.getElementsByClassName("artist-photo")[0];
var artistBio = document.getElementsByClassName("artist-bio")[0];
var i = this.getAttribute("src").indexOf(".jpg");
var photoName = this.getAttribute("src").slice (0, i);
artistPhoto.style.background="url(" + photoName + "-large.jpg";
console.log("it happened");
}
}(i));
}
$('body *').on('mouseover',function(){console.log(this.tagName)});