Question

我有一个简单的选择框。当用户选择选项时，应显示包含某些代码的图像和文本框：

 <select name="state" id="state" style="margin-bottom: 1em;">
      <option value="AL">Alabama</option>
      <option value="AK">Alaska</option>
      <option value="AZ">Arizona</option>
      <!-- etc. etc. -->
 </select>

 <div id="badgeView"></div>

 <div id="codewrap" >
      <textarea id="codeView" readonly="readonly"></textarea>
 </div>

这是脚本：

/* Helpful variables */ 
var codeTemplate = '<a href="http://www.nonprofitvote.org/voting-in-yourstate.html" title="Voting in Your State">\n' + '<img src="http://nonprofitvote.org/images/badges/voting_in_yourstate.jpg" alt="Voting in Your State" />\n' + '</a>';
var state = document.getElementById('state');
var badgeView = document.getElementById('badgeView');
var codeView = document.getElementById('codeView');

/* Load up AL's image and code when the page first loads */
changeBadgeAndCode();

/* What to do when the user selects an option */
state.addEventListener('change', changeBadgeAndCode, false);

/* What to do if a user clicks in the code view text box */
codeView.addEventListener('click', selectText, false);

/* Function declarations */
function changeBadgeAndCode(){
    changeBadgeView(badgeView);
    changeCodeView(codeView);

    var stateName = state.options[state.selectedIndex].value.toLowerCase();

    function changeBadgeView(element) {
        element.innerHTML = '<img src="http://www.nonprofitvote.org/images/badges/voting_in_' + stateName + '.jpg" />';
    }

    function changeCodeView(element) {
        codeTemplate = codeTemplate.replace(/yourstate/g, stateName);
        codeTemplate = codeTemplate.replace(/Your State/g, stateName);
        element.innerHTML = codeTemplate;
    }
}
function selectText(){this.select()}

如果我提醒stateName，我会得到一个反映我的选项选择的值。但是这个stateName变量似乎没有进入changeBadgeView和changeCodeView函数。我不明白为什么。有什么想法吗？

Answer 1

您在为changeBadgeView分配了值之前调用了changeCodeView和stateName。

你需要先做作业......

function changeBadgeAndCode(){
    var stateName = state.options[state.selectedIndex].value.toLowerCase();

    changeBadgeView(badgeView);
    changeCodeView(codeView);

    function changeBadgeView(element) {
        element.innerHTML = '<img src="http://www.nonprofitvote.org/images/badges/voting_in_' + stateName + '.jpg" />';
    }

    function changeCodeView(element) {
        codeTemplate = codeTemplate.replace(/yourstate/g, stateName);
        codeTemplate = codeTemplate.replace(/Your State/g, stateName);
        element.innerHTML = codeTemplate;
    }
}

变量不适用于后代函数，涉及的事件

1 个答案: