Javascript错误/小故障?

Javascript错误/小故障?,javascript,html5-canvas,Javascript,Html5 Canvas,我有这个修改过的矩阵Javascript代码,我想去掉第一次运行的所有重叠字符串。有人知道我该怎么办吗?我还想在我的网页上多次使用此代码我需要声明新变量,不是吗?但是当我在不同的页面上使用它时,我不必这样做,对吗?然而,我两个都试过了,但都不起作用。。。我将感谢任何帮助。谢谢 您可以在此处看到完整的代码: 这是我的js代码: <script type="text/javascript"> var c = document.getElementById("c"); var ctx =

我有这个修改过的矩阵Javascript代码,我想去掉第一次运行的所有重叠字符串。有人知道我该怎么办吗?我还想在我的网页上多次使用此代码我需要声明新变量,不是吗?但是当我在不同的页面上使用它时,我不必这样做,对吗?然而,我两个都试过了,但都不起作用。。。我将感谢任何帮助。谢谢 您可以在此处看到完整的代码:

这是我的js代码:

<script type="text/javascript"> var c = document.getElementById("c");
var ctx = c.getContext("2d");

document.getElementById("c").style.backgroundColor = 'rgba(255, 255, 255)';

c.height = 450;
c.width = window.innerWidth;

//chinese characters - taken from the unicode charset
var chinese = ["paylessshoes.com.au" , 
"ralphlaurenoutlet.com.au","uloadit.com.au" ,"forsterbus.com.au", 
"deanwoods.com.au" , "deanwoods.com.au" , "agelessinstantly.com.au", 
"stayhuman.com.au" , "lyndhursthotel.com.au" , "gothicweddings.com.au" , 
"growing-home.com.au" , "veglife.com.au" , 
"anagomes.com.au","soulcentralsydney.com.au" , 
 "manninghammedicalcentre.com.au" ];


var font_size = 15;
var columns = c.width/font_size; //number of columns for the rain
//an array of drops - one per column
var drops = [];
//x below is the x coordinate
//1 = y co-ordinate of the drop(same for every drop initially)
for(var x = 0; x < columns; x++)
drops[x] = 1; 

//drawing the characters
function draw()
{
//White BG for the canvas
//translucent BG to show trail
ctx.fillStyle = "rgba(255, 255, 255, 0.35)";
ctx.fillRect(0, 0, c.width, c.height);

ctx.fillStyle = "#243c84"; //blue text
ctx.font = font_size + "px arial";
//looping over drops
for(var i = 0; i < drops.length; i++)
{
    //a random chinese character to print
    var text = chinese[Math.floor(Math.random()*chinese.length)];
    //x = i*font_size, y = value of drops[i]*font_size
    ctx.fillText(text, i*font_size, drops[i]*font_size);


//sending the drop back to the top randomly after it has crossed the screen
    //adding a randomness to the reset to make the drops scattered on the Y axis
    if(drops[i]*font_size > c.height && Math.random() > 0.980)
        drops[i] = 0;

    //incrementing Y coordinate
    drops[i]++;
 }
}

setInterval(draw, 150); </script>
var c=document.getElementById(“c”);
var ctx=c.getContext(“2d”);
document.getElementById(“c”).style.backgroundColor='rgba(255,255,255)';
c、 高度=450;
c、 宽度=window.innerWidth;
//中文字符-取自unicode字符集
var chinese=[“paylesshoes.com.au”,
“ralphlaureoutlet.com.au”、“uloadit.com.au”、“forsterbus.com.au”,
“deanwoods.com.au”、“deanwoods.com.au”、“agelessinstantly.com.au”,
“stayhuman.com.au”、“lyndhursthotel.com.au”、“gothicweddings.com.au”,
“成长家园”和“素食生活”,
“anagomes.com.au”、“soulcentralsydney.com.au”,
“manninghammedicalcentre.com.au”];
var font_size=15;
var columns=c.width/font\u size//雨的列数
//一组水滴-每列一滴
var下降=[];
//下面的x是x坐标
//1=落差的y坐标(每个落差的初始坐标相同)
对于(变量x=0;xc.height&&Math.random()>0.980)
滴[i]=0;
//递增Y坐标
滴[i]++;
}
}
设置间隔(抽签,150);
和HTML:

要删除重叠第一行的下降,可以将下降y偏移初始化为画布底部下方的行,而不是顶部行:

var rowOffCanvas = Math.ceil( c.height/font_size) + 1;
for(var x = 0; x < columns; x++) {
    drops[x] = rowOffCanvas;  // instead of 1
}
var rowOffCanvas=Math.ceil(c.height/font\u size)+1;
对于(变量x=0;x
因此,可以轻松优化绘图功能,以避免绘制画布:

if( drops[i] < rowOffCanvas) {
    ctx.fillText(text, i*font_size, drops[i]*font_size);
}
if(删除[i]

如果在同一页面上有多个不同的拖放效果,则它们需要单独存储其数据值(显然,正如您所假设的)。通常,这可以通过将单个拖放效果(包括画布上下文)的所有数据存储在每个效果唯一的对象中来实现。选择使用对象文本、构造函数或类声明来实现这一点取决于您,请记住类声明是ES6的一部分,IE不支持。

有什么错误吗?如果您在初始化和第一次拖放期间查看画笔,每个“名称”都会重叠,并且看起来不好,因为您无法读取任何内容。我指的是第一段下降的线路。我想这是所有我放在一起的线。在那之后一切都很好。即使它不一定是一个错误,但如果可能的话,我想删除它