即使 css 设置为 display ， display 属性也会返回 null : block

<div id = "Info">
    <p id = "Name">
   ......
</div>

<input type = "button" value = "Edit" id = "Edit_button">

<div id = "Edit">
    ....
    </div>

CSS：

#Info {
    display: block;
}

#Edit_button {
    display: none;
}

#Edit {
    display: none;
}

下面的函数是点击上面的按钮时的回调。

 function main(){
    var info = document.getElementById("Info");
    var edit = document.getElementById("Edit");
    var edit_button = document.getElementById("Edit_button");
    alert("INFO" + info.style.display + " Edit" + edit.style.display + " Edit_Button" + edit_button.style.display);
    var json = document.body.json;
    if(info.style.display == "none" && edit.style.display == "block"){
        edit.style.display = "none";
        info.style.display = "block";
        edit_button.style.display = "block";
        waitForElements("Info");
        addJSONtoEdit(json);
    }
    if(edit.style.display == "none" && info.style.display == "block"){
        info.style.display = "none";
        edit_button.style.display = "none";
        edit.style.display = "block";
        waitForElements("Edit");        
        addJSONtoEdit(json);
    }
}

问题是，我单击按钮并显示警报 -

因此，这些ifs都不起作用。