使用 javascript 更改可见性

Question

嗨 我有一个网页，它使用 ajax 从其他页面检索数据，同时我想在页面中显示加载 gif，所以我创建了一个带有我的 gif 的 div。

 <div id="loading"><img src="images/loadinfo.net.gif" width="48" height="48" /></div>

这是我的css代码：

#content #loading {
    visibility:hidden;
    position: fixed;
    width: 48px;
    top: 0px;
}

现在我想我需要做的就是在加载内容 ajax 函数开始时将加载 div 的可见性设置为“可见”，然后在最后将其再次隐藏 但奇怪的是，如果我创建加载 div 可见，然后在 ajax 函数的开头将其隐藏，它工作正常！！！

这是我的功能：

function ajaxpage(url, containerid) {
    document.getElementById('loading').style.visibility = 'visible';

    var bustcachevar = 1 //bust potential caching of external pages after initial request? (1=yes, 0=no)
    var loadedobjects = ""
    var rootdomain = "http://" + window.location.hostname
    var bustcacheparameter = ""

    var page_request = false
    if (window.XMLHttpRequest) // if Mozilla, Safari etc
    page_request = new XMLHttpRequest()
    else if (window.ActiveXObject) { // if IE
        try {
            page_request = new ActiveXObject("Msxml2.XMLHTTP")
        } catch (e) {
            try {
                page_request = new ActiveXObject("Microsoft.XMLHTTP")
            } catch (e) {}
        }
    } else
    return false
    page_request.onreadystatechange = function () {
        loadpage(page_request, containerid)
    }
    if (bustcachevar) //if bust caching of external page
    bustcacheparameter = (url.indexOf("?") != -1) ? "&" + new Date().getTime() : "?" + new Date().getTime()
    page_request.open('GET', url + bustcacheparameter, true)
    page_request.send(null)
}

function loadpage(page_request, containerid) {
    if (page_request.readyState == 4 && (page_request.status == 200 || window.location.href.indexOf("http") == -1)) document.getElementById(containerid).innerHTML = page_request.responseText

}

function loadobjs() {
    if (!document.getElementById) return
    for (i = 0; i < arguments.length; i++) {
        var file = arguments[i]
        var fileref = ""
        if (loadedobjects.indexOf(file) == -1) { //Check to see if this object has not already been added to page before proceeding
            if (file.indexOf(".js") != -1) { //If object is a js file
                fileref = document.createElement('script')
                fileref.setAttribute("type", "text/javascript");
                fileref.setAttribute("src", file);
            } else if (file.indexOf(".css") != -1) { //If object is a css file
                fileref = document.createElement("link")
                fileref.setAttribute("rel", "stylesheet");
                fileref.setAttribute("type", "text/css");
                fileref.setAttribute("href", file);
            }
        }
        if (fileref != "") {
            document.getElementsByTagName("head").item(0).appendChild(fileref)
            loadedobjects += file + " " //Remember this object as being already added to page
        }
    }
    document.getElementById('loading').style.visibility = 'hidden';
}

Answer 1

function loadpage (page_request, containerid)
{
  var loading = document.getElementById ( "loading" ) ;

  // when connecting to server
  if ( page_request.readyState == 1 )
      loading.style.visibility = "visible" ;

  // when loaded successfully
  if (page_request.readyState == 4 && (page_request.status==200 || window.location.href.indexOf("http")==-1))
  {
      document.getElementById(containerid).innerHTML=page_request.responseText ;
      loading.style.visibility = "hidden" ;
  }
}

Answer 2

如果您只想在收到响应时显示它，请将其添加到您的 loadpage()

function loadpage(page_request, containerid){
   if (page_request.readyState == 4 && page_request.status==200) { 
      var container = document.getElementById(containerid);
      container.innerHTML=page_request.responseText;
      container.style.visibility = 'visible';
      // or 
      container.style.display = 'block';
}

但这完全取决于你最初是如何隐藏 div 的

Answer 3

使用显示而不是可见性。 display: none 为不可见，无设置为可见。