不知道為什么 效果只能顯示一部分,height的高度也撐開了的啊
這是HTML代碼
<!DOCTYPE?html> <html?lang="en"> <head> ????<meta?charset="UTF-8"> ????<title>canvas倒計時效果</title> </head> <body?style="height:?100%"> <canvas?id="canvas"?style="height:?100%"> ????當(dāng)前瀏覽器不支持Canvas,請更換瀏覽器后再試 </canvas> <script?src="digit.js"></script> <!--<script?src="canvas03.js"></script>--> <script?src="canvas%20daojishi.js"></script> <!--<script?src="canvas01.js"></script>--> <!--<script?src="countdown.js"></script>--> </body> </html>
這是js代碼
var?canvas_width=1024; var?canvas_height=768; var?radius=8; var?margin_top=60; var?margin_left=30; //const修飾的數(shù)據(jù)類型是指常類型,常類型的變量或?qū)ο蟮闹凳遣荒鼙桓碌??//endtime?截至?xí)r間 //?const?endTime=new?Date(2016,10,7,0,0,0);?//new?date()?不能超過距離現(xiàn)在的99小時?因?yàn)樾r設(shè)定只有兩位數(shù)?只能99小時?4天?月份0——11 //自動更新時間 var?endTime=new?Date();??//得到當(dāng)前的時間 endTime.setTime(endTime.getTime()+3600*1000);??//設(shè)置當(dāng)前時間(得到當(dāng)前時間(毫秒)+1h(3600)s*1000轉(zhuǎn)換為毫秒) var?curShowTimeSeconds=0;?//當(dāng)前時間秒數(shù)為0 var?balls?=?[]; const?colors?=?["#33B5E5","#0099CC","#AA66CC","#9933CC","#99CC00","#669900","#FFBB33","#FF8800","#FF4444","#CC0000"]; window.onload=function?()?{ ????var?canvas=document.getElementById("canvas"); ????//?canvas.width=canvas_width; ????//?canvas.height=canvas_height; ????//屏幕自適應(yīng) ????canvas_width=document.body.clientWidth; ????canvas_height=document.body.clientHeight; ????margin_left=Math.round(canvas_width/10); ????margin_top=Math.round(canvas_height/5); ????radius=Math.round((canvas_width*4/5)/108)-1; ????//render這個函數(shù)里面有個renderDigit() ????//依次繪制時分秒的每個數(shù)字,秒的個位數(shù)到區(qū)域左邊的距離是?93*(R+1), ????//并且本身一個數(shù)的寬度是15*(R+1), ????//所以得到了區(qū)域總寬為93*(R+1)+15*(R+1)=108*(R+1), ????//也就是window_width*4/5?=?108?*(R+1); ????var?context=canvas.getContext("2d"); ???? ????curShowTimeSeconds=getCurrentShowTimeSeconds(); ????//?render(context);??//渲染?具體繪制??//替換為setInterval() ????//動畫效果的實(shí)現(xiàn) ????setInterval( ????????function?()?{ ????????????render(context);??//在畫布上描述?//下面已完成 ????????????update();??//數(shù)據(jù)的變化 ????????},50 ????) }; function?getCurrentShowTimeSeconds()?{ ????var?curTime=new?Date();?//取得當(dāng)前的時間 ????var?retTime=endTime.getTime()-curTime.getTime();?//倒計時=結(jié)束時間-當(dāng)前時間???//getTime()??得到毫秒數(shù) ????retTime=Math.round(retTime/1000);??//round()?方法可把一個數(shù)字舍入為最接近的整數(shù)。//??ret/1000?把毫秒轉(zhuǎn)換為秒 ????return?retTime>=0??retTime:0;??//判斷reTime是否>=0?如果是?則返回?ret?否則返回0 } function?update()?{ ????//1.時間變化 ????var?nextShowTimeSeconds=getCurrentShowTimeSeconds();??//下一個時間 ????//下一個時間分解 ????var?nextHours=parseInt(nextShowTimeSeconds/3600); ????var?nextMinutes=parseInt((nextShowTimeSeconds-nextHours*3600)/60); ????var?nextSeconds=nextShowTimeSeconds%60; ????//當(dāng)前時間分解 ????var?curHours=parseInt(curShowTimeSeconds/3600); ????var?curMinutes=parseInt((curShowTimeSeconds-curHours*3600)/60); ????var?curSeconds=curShowTimeSeconds%60; ????//2.添加小球位置的變化 ?????if?(nextSeconds?!=?curSeconds)?{?//判斷下一個時間是否等于當(dāng)前的時間//當(dāng)不等于的時候 ????????????//小時 ????????????if?(parseInt(curHours?/?10)?!=?parseInt(nextHours?/?10))?{ ????????????????addBalls(margin_left,?margin_top,?parseInt(curHours?/?10));?//位置?X?Y?以及?相應(yīng)的數(shù)字 ????????????} ????????????if?(parseInt(curHours?%?10)?!=?parseInt(nextHours?%?10))?{ ????????????????addBalls(margin_left?+?15?*?(radius?+?1),?margin_top,?parseInt(curHours?%?10)) ????????????} ????????????//分鐘 ????????????if?(parseInt(curMinutes?/?10)?!=?parseInt(nextMinutes?/?10))?{ ????????????????addBalls(margin_left?+?39?*?(radius?+?1),?margin_top,?parseInt(curMinutes?/?10)); ????????????} ????????????if?(parseInt(curMinutes?%?10)?!=?parseInt(nextMinutes?%?10))?{ ????????????????addBalls(margin_left?+?54?*?(radius?+?1),?margin_top,?parseInt(curMinutes?%?10)); ????????????} ????????????//秒鐘 ????????????if?(parseInt(curSeconds?/?10)?!=?parseInt(nextSeconds?/?10))?{ ????????????????addBalls(margin_left?+?78?*?(radius?+?1),?margin_top,?parseInt(curSeconds?/?10)); ????????????} ????????????if?(parseInt(curSeconds?%?10)?!=?parseInt(nextSeconds?%?10))?{ ????????????????addBalls(margin_left?+?93?*?(radius?+?1),?margin_top,?parseInt(curSeconds?%?10)); ????????????} ????????????curShowTimeSeconds?=?nextShowTimeSeconds;??//當(dāng)前的時間就是==下一個時間 ????????} ????????updateBalls();??//更新所有的小球 ????????console.log(balls.length);??//在控制臺打印balls的長度??//不停加長??//解決性能優(yōu)化 ????} ??????? ???????? function?updateBalls()?{ ????//1.小球運(yùn)動值的變化?//.碰撞檢測 ????for?(var?i=0;i<balls.length;i++){ ????????balls[i].x+=balls[i].vx; ????????balls[i].y+=balls[i].vy; ????????balls[i].vy+=balls[i].g; ????????if?(balls[i].y>=canvas_height-radius)?{ ???????????balls[i].y?=?canvas_height?-?radius; ???????????balls[i].vy?=?-balls[i].vy?*?0.75;??//0.75摩擦系數(shù)?越大越遠(yuǎn) ???????} ????} ????//2.性能優(yōu)化?刪除小球 ????var?cnt=0;??//小球數(shù)量 ????for?(var?i=0;i<balls.length;i++) ????????//右邊緣>0?和?左邊緣<canvas.width?說明在畫布內(nèi)?然后放在數(shù)組里 ????????if(balls[i].x+radius>0?&&?balls[i].x-radius<canvas_width) ????????????balls[cnt++]?=?balls[i]; ????while?(balls.length>Math.min(200,cnt)){??//保留200到cnt之間的最小值 ????????balls.pop();??//pop()用于刪除并返回數(shù)組的最后一個元素 ????} } function?addBalls(x,y,num)?{???//運(yùn)動的彩色小球 ????for?(var?i=0;i<digit[num].length;i++) ???????for?(var?j=0;j<digit[num][i].length;j++) ??????????if?(digit[num][i][j]==1){ ??????????????var?aBall={ ??????????????????x:x+j*2*(radius+1)+(radius+1), ??????????????????y:y+i*2*(radius+1)+(radius+1), ??????????????????g:1.5+Math.random(),??//加速度?1.5-2.5?//?不同 ??????????????????//?在X軸上的加速度?//Math.round()?四舍五入取整??//random()?0?~?1?之間?隨機(jī)數(shù)。 ??????????????????vx:?Math.pow(-1,?Math.ceil(Math.random()?*?1000))?*?4,??//1-1000//取整?//取-1?或+1?//*4//-4至+4 ??????????????????//?Math.ceil向上取整??//pow()?方法可返回?x?的?y?次冪的值。在這里是?-1的N次冪 ??????????????????vy:?-5,??//向上拋一點(diǎn)點(diǎn) ??????????????????//math.floor(x)對浮點(diǎn)數(shù)向下取整??// ??????????????????color:?colors[Math.floor(Math.random()?*?colors.length)]?//顏色數(shù)組 ??????????????}; ??????????????balls.push(aBall); ??????????} } function?render(cxt)?{???//在畫布上描述 ????cxt.clearRect(0,0,canvas_width,canvas_height);??//clearRect()?方法清空給定矩形內(nèi)的指定像素??//畫布更新??//時間變化不重復(fù) ????//當(dāng)前的時間 ????var?hours=parseInt(curShowTimeSeconds/3600); ????var?minutes=parseInt((curShowTimeSeconds-hours*3600)/60);??//(現(xiàn)在秒-當(dāng)前秒?)/60??=分鐘 ????var?seconds=curShowTimeSeconds%60;??//倒計時具體時間??//%60取余 ????renderDigit(margin_left,margin_top,parseInt(hours/10),cxt)?;??//小時?//十位數(shù)??//?第一位?//起始位置?x?y ????renderDigit(margin_left+15*(radius+1),margin_top,parseInt(hours%10),cxt);?//小時//個位數(shù)//第二位// ???? ????renderDigit(margin_left+30*(radius+1),margin_top,10,cxt);??//冒號 ???? ????renderDigit(margin_left+39*(radius+1),margin_top,parseInt(minutes/10),cxt);?//分鐘//第三位 ????renderDigit(margin_left+54*(radius+1),margin_top,parseInt(minutes%10),cxt);?//分鐘//第四位 ????renderDigit(margin_left+69*(radius+1),margin_top,10,cxt);??//冒號 ????renderDigit(margin_left+78*(radius+1),margin_top,parseInt(seconds/10),cxt);??//秒鐘//第五位 ????renderDigit(margin_left+93*(radius+1),margin_top,parseInt(seconds%10),cxt);??//秒鐘//第六位 ????//繪制小球 ????for?(var?i=0;i<balls.length;i++){ ????????cxt.fillStyle=balls[i].color; ????????cxt.beginPath(); ????????cxt.arc(balls[i].x,balls[i].y,radius,0,2*Math.PI,true); ????????cxt.closePath(); ????????cxt.fill(); ????} } //具體的循環(huán)//規(guī)定何處填充顏色 function?renderDigit(x,y,num,cxt)?{??//傳入4個參數(shù)??X?Y?num?cxt ????cxt.fillStyle="#00ff00";??//定義好顏色 ????for?(var?i=0;i<digit[num].length;i++)???//不能有; ?????????for?(var?j=0;j<digit[num][i].length;j++)?????//不能有; ????if?(digit[num][i][j]==1){?????//畫圓 ????????cxt.beginPath(); ????????cxt.arc(x+j*2*(radius+1)+(radius+1),y+i*2*(radius+1),radius,0,2*Math.PI); ????????cxt.closePath(); ????????cxt.fill(); ????} }
可是顯示出來是這樣的 為什么呢?
2017-04-15
把寬度也撐開100%就行了
2017-04-12
把html的高度也撐開
2017-01-16
試一下
2016-11-07
給html也加一個高度試試