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小程式使用Canvas畫餅圖

先上效果圖

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<view class="canvas-content"> <canvas canvas-id="Canvas" style="width:100%;height:360px;"></canvas></view>

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Page({ data: {

}, onLoad: function () { var context = wx.createCanvasContext('Canvas', this); var array = [20, 50, 60,80]; var colors = ["#228B22","pink", "#008B8B", "#ADFF2F"]; var total = 0; for (var val = 0; val < array.length; val++) { total += array[val]; } var point = { x: 160, y: 120 }; var radius = 100; for (var i = 0; i < array.length; i++) { context.beginPath(); var start = 0; if (i > 0) { for (var j = 0; j < i; j++) { start += array[j] / total * 2 * Math.PI; } } var end = start + array[i] / total * 2 * Math.PI; context.arc(point.x, point.y, radius, start, end); context.setLineWidth(2) context.lineTo(point.x, point.y); context.setStrokeStyle('#F5F5F5'); context.setFillStyle(colors[i]); context.fill(); context.closePath(); context.stroke(); } context.draw(); }})

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