js怎么实现弹幕功能
具体操作方法：
首先创建一个html文件。
在html文件中添加html代码架构。
<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>弹幕功能</title> </head> <body> </body> </html>
然后在html代码架构中的body标签里面使用div、input、button标签分别给页面设计一个效果显示框、输入框、弹幕提交按钮。
<div id="box" class="box"></div> <input type="text" id="txt" /> <button onclick="send()">发送弹幕</button>
在html架构中的html标签里面添加script标签并写入js代码来实现弹幕效果。
<script>
function $(str) {
return document.getElementById(str);
}
function send() {
var word = $('txt').value;
var span = document.createElement('span');
var top = parseInt(Math.random() * 500) - 20;
var color1 = parseInt(Math.random() * 256);
var color2 = parseInt(Math.random() * 256);
var color3 = parseInt(Math.random() * 256);
var color = "rgb(" + color1 + "," + color2 + "," + color3 + ")";
top = top < 0 ? 0 : top;
span.style.position = 'absolute';
span.style.top = top + "px";
span.style.color = color;
span.style.left = '500px';
span.style.whiteSpace = 'nowrap';
var nub = (Math.random() * 10) + 1;
span.setAttribute('speed', nub);
span.speed = nub;
span.innerHTML = word;
$('box').appendChild(span);
$('txt').value = "";
}
setInterval(move, 200);
function move() {
var spanArray = $('box').children;
for (var i = 0; i < spanArray.length; i++) {
spanArray[i].style.left = parseInt(spanArray[i].style.left) - spanArray[i].speed + 'px';
}
}
</script>最后可通过浏览器方式阅读html文件查看设计效果。
完整示例代码如下：
<div id="box" class="box"></div>
<input type="text" id="txt" />
<button onclick="send()">发送弹幕</button>
<script>
function $(str) {
return document.getElementById(str);
}
function send() {
var word = $('txt').value;
var span = document.createElement('span');
var top = parseInt(Math.random() * 500) - 20;
var color1 = parseInt(Math.random() * 256);
var color2 = parseInt(Math.random() * 256);
var color3 = parseInt(Math.random() * 256);
var color = "rgb(" + color1 + "," + color2 + "," + color3 + ")";
top = top < 0 ? 0 : top;
span.style.position = 'absolute';
span.style.top = top + "px";
span.style.color = color;
span.style.left = '500px';
span.style.whiteSpace = 'nowrap';
var nub = (Math.random() * 10) + 1;
span.setAttribute('speed', nub);
span.speed = nub;
span.innerHTML = word;
$('box').appendChild(span);
$('txt').value = "";
}
setInterval(move, 200);
function move() {
var spanArray = $('box').children;
for (var i = 0; i < spanArray.length; i++) {
spanArray[i].style.left = parseInt(spanArray[i].style.left) - spanArray[i].speed + 'px';
}
}
</script>
