將事件添加到數組的元素

Question

我試圖在數組中創建一個循環，並向其元素添加事件，而不是成功。 這是數組：

div_empresa_links_elements.push({
    div_mouseover: div_imagens_mouseover,
    div_submenu: div_empresa_imagens,
    div_txt: div_imagens_txt
}, {
    div_mouseover: div_institucional_mouseover,
    div_submenu: div_empresa_institucional,
    div_txt: div_institucional_txt
}, {
    div_mouseover: div_localizacao_mouseover,
    div_submenu: div_empresa_localizacao,
    div_txt: div_localizacao_txt
}, {
    div_mouseover: div_infraestrutura_mouseover,
    div_submenu: div_empresa_infraestrutura,
    div_txt: div_infraestrutura_txt
}, {
    div_mouseover: div_politicaDeQualidade_mouseover,
    div_submenu: div_empresa_politicaDeQualidade,
    div_txt: div_politicaDeQualidade_txt
}, {
    div_mouseover: div_linhaDoTempo_mouseover,
    div_submenu: div_empresa_linhaDoTempo,
    div_txt: div_linhaDoTempo_txt
}, {
    div_mouseover: div_historico_mouseover,
    div_submenu: div_empresa_historico,
    div_txt: div_historico_txt
})

這是循環：

for (var i = 0; i < div_empresa_links_elements.length; i++) {
    var obj = div_empresa_links_elements[i]
    obj.div_mouseover.onmouseover = function () {
        obj.div_txt.style.opacity = 1
        obj.div_txt.style.filter = 'alpha(opacity = 100)'
        obj.div_submenu.style.opacity = .7
        obj.div_submenu.style.filter = 'alpha(opacity = 70)'
    }
}

如果我手動為每個元素（_mouseover）放置一個事件，而沒有循環，那么事情就起作用了。 誰能告訴我為什么？

Answer 1

問題是由關閉問題引起的。 當前， obj在每次迭代時都會被覆蓋。 因此， obj指向最后定義的元素。 要解決此問題，請將循環的主體包裝在自調用函數中，並將變量obj作為參數傳遞，如下所示：

 for (var i = 0; i<div_empresa_links_elements.length;i++){
    var obj = div_empresa_links_elements[i]
    (function(obj){ //obj is declared again. Inside this func, obj = <see below>
        obj.div_mouseover.onmouseover = function(){
            obj.div_txt.style.opacity = 1
            obj.div_txt.style.filter = 'alpha(opacity = 100)'
            obj.div_submenu.style.opacity = .7
            obj.div_submenu.style.filter = 'alpha(opacity = 70)'
        }
    })(obj); //Pass the variable obj as defined at the top
}