因为您的脚本在运行之前运行,所以标签存在于页面中(在DOM中)。可以将脚本放在标签后,或者等待文档完全加载(使用OnLoad函数)
这行不通:
<script>
document.getElementById('lbltipAddedComment').innerHTML = 'your tip has been submitted!';
</script>
<label id="lbltipAddedComment">test</label>
这将起作用:
<label id="lbltipAddedComment">test</label>
<script>
document.getElementById('lbltipAddedComment').innerHTML = 'your tip has been submitted!';
</script>
此示例(jsfiddle链接)维护顺序(首先是脚本,然后是标签),并使用onLoad:
<label id="lbltipAddedComment">test</label>
<script>
function addLoadEvent(func) {
var oldonload = window.onload;
if (typeof window.onload != 'function') {
window.onload = func;
} else {
window.onload = function() {
if (oldonload) {
oldonload();
}
func();
}
}
}
addLoadEvent(function() {
document.getElementById('lbltipAddedComment').innerHTML = 'your tip has been submitted!';
});
</script>