我正在尝试创建一个循环的进度条(虽然它不再是一个吧,不是吗?).在这个cricle周围有垂直于圆圈的细条.现在的问题是,我的代码不会产生均匀间距的条形.这是代码和结果的图像:
function MH5PB(canvasId,//the id of the canvas to draw the pb on value,//a float value,representing the progress(ex: 0.3444) background,//the background color of the pb(ex: "#ffffff") circleBackground,//the background color of the bars in the circles integerColor,//the color of the outer circle(or the int circle) floatColor //the color of the inner circle(or the float circle) ) { var canvas = document.getElementById(canvasId); var context = canvas.getContext("2d"); var canvasWidth = canvas.width; var canvasHeight = canvas.height; var radius = Math.min(canvasWidth,canvasHeight) / 2; var numberOfBars = 72; var barThickness = 2; //margin from the borders,and also the space between the two circles var margin = parseInt(radius / 12.5) >= 2 ? parseInt(radius / 12.5) : 2; //the thickness of the int circle and the float circle var circleThickness = parseInt((radius / 5) * 2); //the outer radius of the int circle var intOuterRadius = radius - margin; //the inner radius of the int circle var intInnerRadius = radius - margin - circleThickness; //the outer radius of the float circle var floatOuterRadius = intOuterRadius - margin - circleThickness; //the inner radius of the float circle var floatInnerRadius = floatOuterRadius - circleThickness; //draw a bar,each degreeStep degrees var intCircleDegreeStep = 5; // ((2 * Math.PI * intOuterRadius) / (barThickness + 10)) // // this area is the total number of required bars // // to fill the intCircle.1px space between each bar// var floatCircleDegreeStep = 360 / ((2 * Math.PI * floatOuterRadius) / (barThickness + 10)); context.lineWidth = barThickness; context.strokeStyle = circleBackground; //draw the bg of the outer circle for(i = 90; i < 450; i+=intCircleDegreeStep) { //since we want to start from top,and move cw,we have to map the degree //in the loop cxOuter = Math.floor(intOuterRadius * Math.cos(i) + radius); cyOuter = Math.floor(intOuterRadius * Math.sin(i) + radius); cxInner = Math.floor(intInnerRadius * Math.cos(i) + radius); cyInner = Math.floor(intInnerRadius * Math.sin(i) + radius); context.moveTo(cxOuter,cyOuter); context.lineTo(cxInner,cyInner); context.stroke(); } }
编辑:哦,而且行也没有消除锯齿.你知道为什么吗?
我还应该解释一下,这个进度条由两部分组成.外圈(在提供的图像中可见)和内圈.外圆是百分比的整数部分的量(即45在45.98%中的45),内圆是百分比的非整数部分的量(即,在45.98%中为98).因此,您现在知道intCircle和floatCircle是什么:)
解决方法
看来你正在将学位传递给Math.sin和Math.cos.这些函数需要弧度.例如,
// i degrees to radians. Math.sin(i * (Math.PI / 180));