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/Html5
/Canvas 繪制時鐘
我控制臺輸出var r = width/2;console.log(width+" "+r);width是300,r是150有問題嗎
2016-10-14
源自:Canvas 繪制時鐘 3-2
正在回答
<script type="text/javascript">
var dom = document.getElementById('clock');
var ctx = dom.getContext('2d');
var width = ctx.canvas.width;
var height = ctx.canvas.height;
var r = width/2;
var rem = width/200;
function drawBackground(){
ctx.save();
ctx.translate(r,r);
ctx.beginPath();
ctx.lineWidth = 10*rem;
ctx.arc(0,0,r-ctx.lineWidth/2,0,2*Math.PI,false);
ctx.stroke();
var hourNumbers = [3,4,5,6,7,8,9,10,11,12,1,2];
ctx.font = 18*rem+'px Arial';
ctx.textAlign = 'center';
ctx.textBaseline = 'middle';?
hourNumbers.forEach(function(number,i){
var rad = 2*Math.PI/12*i;
var x = Math.cos(rad)*(r-30*rem);
var y = Math.sin(rad)*(r-30*rem);
ctx.fillText(number,x,y);
});
for (var i = 0; i < 60; i++) {
var rad = 2*Math.PI/60*i;
var x = Math.cos(rad)*(r-18*rem);
var y = Math.sin(rad)*(r-18*rem);
if (i%5 === 0) {
ctx.fillStyle = '#000';
ctx.arc(x,y,2*rem,0,2*Math.PI,false);
}else{
ctx.fillStyle = '#ccc';
}
ctx.fill();
function drowHour(hour,minute){
var rad = 2*Math.PI/12*hour;
var mrad = 2*Math.PI/12/60*minute;
ctx.rotate(rad+mrad);
ctx.lineWidth = 6*rem;
ctx.lineCap = 'round';
ctx.moveTo(0,10*rem);
ctx.lineTo(0,-r/2);
ctx.restore();
function drowMinute(minute){
var rad = 2*Math.PI/60*minute;
ctx.rotate(rad);
ctx.lineWidth = 3*rem;
ctx.lineTo(0,-r+30*rem);
function drowSecond(second){
ctx.fillStyle = '#c14543';
var rad = 2*Math.PI/60*second;
ctx.moveTo(-2*rem,20*rem);
ctx.lineTo(2*rem,20*rem);
ctx.lineTo(1,-r+18*rem);
ctx.lineTo(-1,-r+18*rem);
function drawDot(){
ctx.fillStyle = '#fff';
ctx.arc(0,0,3*rem,0,2*Math.PI,false);
function draw(){
ctx.clearRect(0,0,width,height);
var now = new Date();
var hour = now.getHours();
var minute = now.getMinutes();
var second = now.getSeconds();
drawBackground();
drowHour(hour,minute);
drowMinute(minute);
drowSecond(second);
drawDot();
draw();
setInterval(draw,1000);
</script>
我出來的時鐘是正常的,請參考
慕粉3197089 提問者
無題毛毛 回復 慕粉3197089 提問者
canvas標簽里面加上width=“200”height=“200”
我只能說一句你的在我這也一樣,是瀏覽器的問題?
舉報
canvas畫出漂亮的時鐘,通過本教程能重新掌握一些幾何知識
1 回答代碼一樣。圓沒有出來
4 回答為什么我的圓沒有畫出來啊
4 回答代碼一模一樣,圓畫不出來
2 回答求這兩代碼的區(qū)別,上面的代碼不能畫圓
3 回答誰幫我看一下哪錯了,為什么出不來效果,只有一個矩形出來了?
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2016-10-14
<script type="text/javascript">
var dom = document.getElementById('clock');
var ctx = dom.getContext('2d');
var width = ctx.canvas.width;
var height = ctx.canvas.height;
var r = width/2;
var rem = width/200;
function drawBackground(){
ctx.save();
ctx.translate(r,r);
ctx.beginPath();
ctx.lineWidth = 10*rem;
ctx.arc(0,0,r-ctx.lineWidth/2,0,2*Math.PI,false);
ctx.stroke();
var hourNumbers = [3,4,5,6,7,8,9,10,11,12,1,2];
ctx.font = 18*rem+'px Arial';
ctx.textAlign = 'center';
ctx.textBaseline = 'middle';?
hourNumbers.forEach(function(number,i){
var rad = 2*Math.PI/12*i;
var x = Math.cos(rad)*(r-30*rem);
var y = Math.sin(rad)*(r-30*rem);
ctx.fillText(number,x,y);
});
for (var i = 0; i < 60; i++) {
var rad = 2*Math.PI/60*i;
var x = Math.cos(rad)*(r-18*rem);
var y = Math.sin(rad)*(r-18*rem);
ctx.beginPath();
if (i%5 === 0) {
ctx.fillStyle = '#000';
ctx.arc(x,y,2*rem,0,2*Math.PI,false);
}else{
ctx.fillStyle = '#ccc';
ctx.arc(x,y,2*rem,0,2*Math.PI,false);
}
ctx.fill();
}
}
function drowHour(hour,minute){
ctx.save();
ctx.beginPath();
var rad = 2*Math.PI/12*hour;
var mrad = 2*Math.PI/12/60*minute;
ctx.rotate(rad+mrad);
ctx.lineWidth = 6*rem;
ctx.lineCap = 'round';
ctx.moveTo(0,10*rem);
ctx.lineTo(0,-r/2);
ctx.stroke();
ctx.restore();
}
function drowMinute(minute){
ctx.save();
ctx.beginPath();
var rad = 2*Math.PI/60*minute;
ctx.rotate(rad);
ctx.lineWidth = 3*rem;
ctx.lineCap = 'round';
ctx.moveTo(0,10*rem);
ctx.lineTo(0,-r+30*rem);
ctx.stroke();
ctx.restore();
}
function drowSecond(second){
ctx.save();
ctx.beginPath();
ctx.fillStyle = '#c14543';
var rad = 2*Math.PI/60*second;
ctx.rotate(rad);
ctx.moveTo(-2*rem,20*rem);
ctx.lineTo(2*rem,20*rem);
ctx.lineTo(1,-r+18*rem);
ctx.lineTo(-1,-r+18*rem);
ctx.fill();
ctx.restore();
}
function drawDot(){
ctx.beginPath();
ctx.fillStyle = '#fff';
ctx.arc(0,0,3*rem,0,2*Math.PI,false);
ctx.fill();
}
function draw(){
ctx.clearRect(0,0,width,height);
var now = new Date();
var hour = now.getHours();
var minute = now.getMinutes();
var second = now.getSeconds();
drawBackground();
drowHour(hour,minute);
drowMinute(minute);
drowSecond(second);
drawDot();
ctx.restore();
}
draw();
setInterval(draw,1000);
</script>
我出來的時鐘是正常的,請參考
2016-11-05
canvas標簽里面加上width=“200”height=“200”
2016-10-14
我只能說一句你的在我這也一樣,是瀏覽器的問題?