& lt畫布?id= \"繪圖\"?width=\"400 \"?height=\"400 \" >答?畫畫?的?什麽事!& lt/canvas & gt;& lt劇本?type = \" text/" />
& lthtml & gt
& lthead & gt
& lt/head & gt;
& lt身體?align="center " >
& lt畫布?id= "繪圖"?width="400 "?height="400 " >答?畫畫?的?什麽事!& lt/canvas & gt;
& lt劇本?type = " text/JavaScript " & gt;
//繪制餅圖
var?drawCircle?=?函數(canvasId,data_arr,?color_arr){
var?畫畫?=?document . getelementbyid(canvasId);
if(drawing.getContext)?{
var?語境?=?drawing . get context(' 2d ');
var?半徑?=?drawing.height/2?-20,//半徑
黃牛?=?半徑?+20,?oy?=?半徑?+20;//圓心
var?寬度?=?30,?身高?=?10,?//圖例寬度和高度
posX?=?黃牛?*?2?+20,?波西。=?30;//圖例位置
var?textX?=?posX?+?寬度?+?5,?短信?=?波西。+?10;//文本位置
var?startAngle?=?0,?endAngle?=?0;//開始和結束弧度
context.strokeStyle?=?紫色';
上下文.線寬?=?3;
context.strokeRect(0,0,?繪圖.寬度,?drawing . height);
for(var?i=0,?len=data_arr .長度;?我& ltlen?i++)?{
//繪制餅圖
endAngle?+=?data_arr[i]?*?2 *數學。PI;
context.fillStyle?=?color _ arr[I];
context . begin path();
context.moveTo(ox,oy);
context.arc(ox,oy?半徑,?startAngle,?endAngle?假);
context . close path();
context . fill();
startAngle?=?endAngle
}
}
};
var?初始化?=?函數(){
var?data_arr?=?[0.05,?0.25,?0.6,?0.1],
color_arr?=?['#00FF21 ',?#FFAA00 ',?#00AABB ',?# ff 4400 '];
drawCircle('drawing ',?data_arr,?color _ arr);
};
init();
& lt/script & gt;
& lt/body & gt;
& lt/html & gt;