[js高手之路] html5新增的定时器requestAnimationFrame实战进度条 - ghostwu(2)_H5之家

1 <script> 2 window.onload = function(){ 3 var oBtn = document.querySelector( "input" ), 4 oBox = document.querySelector( "div" ), 5 timer = null, curWidth = 0, 6 getStyle = function( obj, name, value ){ 7 if( obj.currentStyle ) { 8 return obj.currentStyle[name]; 9 }else { 10 return getComputedStyle( obj, false )[name]; 11 } 12 }; 13 oBtn.onclick = function(){ 14 clearTimeout( timer ); 15 oBox.style.width = '0'; 16 timer = setTimeout( function go(){ 17 curWidth = parseInt( getStyle( oBox, 'width' ) ); 18 if ( curWidth < 1000 ) { 19 oBox.style.width = oBox.offsetWidth + 10 + 'px'; 20 oBox.innerHTML = parseInt( getStyle( oBox, 'width' ) ) / 10 + '%'; 21 timer = setTimeout( go, 1000 / 60 ); 22 }else { 23 clearInterval( timer ); 24 } 25 }, 1000 / 60 ); 26 } 27 } 28 </script>

三、requestAnimationFrame方式

1 <!DOCTYPE html> 2 <html lang="en"> 3 <head> 4 <meta charset="UTF-8"> 5 <meta content="width=device-width, initial-scale=1.0"> 6 <meta http-equiv="X-UA-Compatible" content="ie=edge"> 7 <title>Document</title> 8 <style> 9 div{ 10 width:0px; 11 height:40px; 12 border-radius:20px; 13 background:#09f; 14 text-align:center; 15 font:bold 30px/40px '微软雅黑'; 16 color:white; 17 } 18 </style> 19 <script> 20 window.onload = function(){ 21 var oBtn = document.querySelector( "input" ), 22 oBox = document.querySelector( "div" ), 23 timer = null, curWidth = 0, 24 getStyle = function( obj, name, value ){ 25 if( obj.currentStyle ) { 26 return obj.currentStyle[name]; 27 }else { 28 return getComputedStyle( obj, false )[name]; 29 } 30 }; 31 oBtn.onclick = function(){ 32 cancelAnimationFrame( timer ); 33 oBox.style.width = '0'; 34 timer = requestAnimationFrame( function go(){ 35 curWidth = parseInt( getStyle( oBox, 'width' ) ); 36 if ( curWidth < 1000 ) { 37 oBox.style.width = oBox.offsetWidth + 10 + 'px'; 38 oBox.innerHTML = parseInt( getStyle( oBox, 'width' ) ) / 10 + '%'; 39 timer = requestAnimationFrame( go ); 40 }else { 41 cancelAnimationFrame( timer ); 42 } 43 } ); 44 } 45 } 46 </script> 47 </head> 48 <body> 49 <div>0%</div> 50 <p><input type="button" value="ready!Go"></p> 51 </body> 52 </html>