全局变量不会在事件上更改 [英] Global variable not changing on event

问题描述

我有一个名为userValue的全局变量.页面加载时，此值将找到选定的选项并存储该选项值.加载后，由于该选项被禁用，它将存储default或null.但是，在onchange(每个站点动态填充更多选项)时，我试图全局存储所选选项的值，因此我可以简单地继续使用varialbe userValue.当包含以下内容时，我下面的内容可以正常工作:

I have a global variable called userValue. When the page loads, this value is finding the selected option and storing that options value. On load it would be storing default or null since the option is disabled. However, onchange (more options populate dynamically per site), I'm trying to store the value of the selected option globally so I can simply keep reusing the varialbe userValue. What I have below works properly when I include:

   userValue = $('#my_SiteUsers').find(':selected').val(); 

在RefreshGroupList()函数中，但是如果我必须这样做，那是否会破坏拥有全局变量的目的?现在，我所做的任何更改都将返回默认"

in the RefreshGroupList() function, but if i have to do that, doesn't that defeat the purpose of having a global variable? Right now, any change I make returns "default"

HTML:

 <select id="my_SiteUsers" style="width:200px;" onchange="RefreshGroupLists()">
        <option value='default' disabled="disabled">Select a user</option>
      </select>

JS:

  var user, userValue, userText, group, strHTMLSiteUsers, strHTMLSiteGroups, strHTMLAvailable, strHTMLAssigned, arrOptionsAssigned, arrGroups, arrUsers, intOpts, booMatch, booErr;

        $(document).ready(function(){ 
            user = $('#m

y_SiteUsers');
        userValue = $('#my_SiteUsers').find(':selected').val();
        userText = $('#my_SiteUsers').find(':selected').text();
        group = $('#my_SiteGroups');
        groupsAssigned = $("#my_SPGroupsAssigned").html("");
        groupAvailable = $("#my_SPGroupsAvailable").html("");
        userAssigned = $("#my_SPUsersAssigned").html("");
        userAvailable = $("#my_SPUsersAvailable").html("");

        $("button").click(function() { return false; });

        populateUsers();
            populateGroups();
        });


function RefreshGroupLists(){
            //Populate the Groups Assigned
          $().SPServices({
              operation: "GetGroupCollectionFromUser",
              userLoginName: userValue,
              async: true,
              completefunc: function(xData, Status) {
                $(xData.responseXML).find("errorstring").each(function() {
                  alert("User not found");
                  booErr = "true";
                  return;
                });
                $(xData.responseXML).find("Group").each(function() {
                  strHTMLAvailable += "<option value='" + $(this).attr("Name") + "'>" + $(this).attr("Name") + "</option>";
                  arrOptionsAssigned[intOpts] = $(this).attr("Name");
                  intOpts = intOpts + 1;
                });
                groupsAssigned.append(strHTMLAvailable);
              }
          });
}

JSFiddle

推荐答案

由于您打算将$('#my_SiteUsers').find(':selected').val()的值更改为像以前一样对其进行分配，实际上并没有帮助.字符串值被复制按值，需要引用.

Since you intend that the value of $('#my_SiteUsers').find(':selected').val() changes assigning it as you did doesn't really help you. String values are copied by-value, you want a reference.

您可以做的只是保留对DOM元素的引用:

What you can do just keep a reference to the DOM element:

 userValueHolder = $('#my_SiteUsers').find(':selected')

，并在需要时使用useuserValueHolder.val()

这篇关于全局变量不会在事件上更改的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！