實習期間讓我用canvas畫一個表情，比較簡單，話不多說直接上代碼：
<body>
<div id="canvas-warp">
<canvas id="canvas" style="display: block; margin: 200px auto;">
你的瀏覽器居然不支持Canvas!
</canvas>
</div>
<script>
window.onload = function () {
var canvas = document.getElementById("canvas");
canvas.width = 400;
canvas.height = 400;
//獲取上下文
var context = canvas.getContext("2d");
//用於畫有填充色圓的函數 參數分別爲圓心座標 ，半徑，起始與終止位置，線顏色，填充顏色
function drawCircle(x2, y2, r2, a2, b2, lineColor, FillColor) {
context.beginPath();
context.arc(x2, y2, r2, a2, b2 * Math.PI);
context.strokeStyle = lineColor;
context.fillStyle = FillColor;
context.fill(); //確認填充
context.stroke();
};
//用於畫圓弧函數 默認線條爲黑色 無填充 參數分別爲：圓心x座標，圓心y座標，半徑，開始位置，終止位置
function drawsArc(x, y, r, l1, l2) {
context.beginPath();
context.arc(x, y, r, l1 * Math.PI, l2 * Math.PI);
context.strokeStyle = "black";
context.stroke();
};
//用於畫眼睛的函數
function darwEyes(x1, y1, a1, b1) { //參數分別爲橢圓圓心位置 長軸 短軸
context.strokeStyle = "#754924"
ParamEllipse(context, x1, y1, a1, b1); //橢圓
function ParamEllipse(context, x, y, a, b) {
//使每次循環所繪製的路徑（弧線）接近1像素
var step = (a > b) ? 1 / a : 1 / b;
context.beginPath();
context.moveTo(x + a, y); //從橢圓的左端點開始繪製
for (var i = 0; i < 2 * Math.PI; i += step) {
//參數爲i，表示度數（弧度）
context.lineTo(x + a * Math.cos(i), y + b * Math.sin(i));
}
context.closePath();
context.fillStyle = "#754924";
context.fill();
context.stroke();
};
};
//臉
drawCircle(200, 200, 200, 0, 2, "#EEE685", "#FCF200");
//左眼
context.strokeStyle = "#754924"
darwEyes(116, 130, 18, 25);
drawCircle(110, 127, 12, 0, 2, "#754924", "#F5F5F5");
//右眼
darwEyes(296, 130, 18, 25);
drawCircle(290, 127, 12, 0, 2, "#754924", "#F5F5F5");
//左眉毛
drawsArc(100, 100, 50, 1.3, 1.7);
//右眉毛
drawsArc(300, 100, 50, 1.3, 1.7);
//嘴巴
drawsArc(200, 120, 180, 0.3, 0.7);
}
</script></body>
- 效果圖
