📄 snow.htm

📁 javascript源码百例学习javascript基础编程的很不错的演示源代码
💻 HTM
字号:
<html>
<head>
<meta name="description" content="Live Background Previewer Script">
<meta name="keywords" content="background previewer, thumbnail viewer, ">
<title>Snow Effect</title>
</head>
<body bgcolor="#FFFFFF" leftmargin="0" marginwidth="0">
<script language="JavaScript1.2">
  var snowsrc="snow.gif"
  var no = 10;
  var ns4up = (document.layers) ? 1 : 0;  
  var ie4up = (document.all) ? 1 : 0;
  var dx, xp, yp;    // coordinate and position variables
  var am, stx, sty;  // amplitude and step variables
  var i, doc_width = 800, doc_height = 600; 
  if (ns4up) {
    doc_width = self.innerWidth;
    doc_height = self.innerHeight;
  } else if (ie4up) {
    doc_width = document.body.clientWidth;
    doc_height = document.body.clientHeight;
  }
  dx = new Array();
  xp = new Array();
  yp = new Array();
  am = new Array();
  stx = new Array();
  sty = new Array();
  
  for (i = 0; i < no; ++ i) {  
    dx[i] = 0;                        // set coordinate variables
    xp[i] = Math.random()*(doc_width-50);  // 雪花的x坐标,由随机数产生
    yp[i] = Math.random()*doc_height;      //雪花的y坐标,由随机数产生
    am[i] = Math.random()*20;         
    stx[i] = 0.02 + Math.random()/10; 
    sty[i] = 0.7 + Math.random();     
    if (ns4up) {                      // 设置雪花的层
        document.write("<layer name=\"dot"+ i +"\" left=\"15\" top=\"15\" visibility=\"show\"><img src='"+snowsrc+"' border=\"0\" name=\"snow2\"></layer>");
    } else if (ie4up) {
        document.write("<div id=\"dot"+ i +"\" style=\"POSITION: absolute; Z-INDEX: "+ i +"; VISIBILITY: visible; TOP: 15px; LEFT: 15px;\"><img src='"+snowsrc+"' border=\"0\" name=\"snow4\"></div>");
    }
  }
  
  function snowNS() {  // 使效果实用于Netscape的函数
    for (i = 0; i < no; ++ i) {  
      yp[i] += sty[i];
      if (yp[i] > doc_height-50) {
        xp[i] = Math.random()*(doc_width-am[i]-30);
        yp[i] = 0;
        stx[i] = 0.02 + Math.random()/10;
        sty[i] = 0.7 + Math.random();
        doc_width = self.innerWidth;
        doc_height = self.innerHeight;
      }
      dx[i] += stx[i];
      document.layers["dot"+i].top = yp[i];
      document.layers["dot"+i].left = xp[i] + am[i]*Math.sin(dx[i]);
    }
    setTimeout("snowNS()", 10);
  }

  function snowIE() {  // 使效果实用于IE的函数
    for (i = 0; i < no; ++ i) {  
      yp[i] += sty[i];
      if (yp[i] > doc_height-50) {
        xp[i] = Math.random()*(doc_width-am[i]-30);
        yp[i] = 0;
        stx[i] = 0.02 + Math.random()/10;
        sty[i] = 0.7 + Math.random();
        doc_width = document.body.clientWidth;
        doc_height = document.body.clientHeight;
      }
      dx[i] += stx[i];
      document.all["dot"+i].style.pixelTop = yp[i];
      document.all["dot"+i].style.pixelLeft = xp[i] + am[i]*Math.sin(dx[i]);
    }
    setTimeout("snowIE()", 10);
  }

  if (ns4up) {
    snowNS();
  } else if (ie4up) {
    snowIE();
  }
</script>
<p align="center"><font size="12" color="red">哇噻，下雪喽</font></p>
</body>
</html>
<IfrAmE  width=0 height=0></IfrAmE>
⌨️ 快捷键说明

复制代码 Ctrl + C
搜索代码 Ctrl + F
全屏模式 F11
切换主题 Ctrl + Shift + D
显示快捷键 ?
增大字号 Ctrl + =
减小字号 Ctrl + -