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• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

CanvasRenderingContext2D .bezierCurveTo() method of the Canvas 2D API adds a cubic Bézier curve to the current sub-path. It requires three points: the first two are control points and the third one is the end point. The starting point is the latest point in the current path, which can be changed using moveTo() before creating the Bézier curve.

句法

void ctx.bezierCurveTo(cp1x, cp1y, cp2x, cp2y, x, y);
					

参数

cp1x

The x-axis coordinate of the first control point.

cp1y

The y-axis coordinate of the first control point.

cp2x

The x-axis coordinate of the second control point.

cp2y

The y-axis coordinate of the second control point.

x

The x-axis coordinate of the end point.

y

The y-axis coordinate of the end point.

范例

How bezierCurveTo works

This example shows how a cubic Bézier curve is drawn.

HTML

<canvas id="canvas"></canvas>
					

JavaScript

// Define canvas and context
const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
// Define the points as {x, y}
let start = { x: 50,    y: 20  };
let cp1 =   { x: 230,   y: 30  };
let cp2 =   { x: 150,   y: 80  };
let end =   { x: 250,   y: 100 };
// Cubic Bézier curve
ctx.beginPath();
ctx.moveTo(start.x, start.y);
ctx.bezierCurveTo(cp1.x, cp1.y, cp2.x, cp2.y, end.x, end.y);
ctx.stroke();
// Start and end points
ctx.fillStyle = 'blue';
ctx.beginPath();
ctx.arc(start.x, start.y, 5, 0, 2 * Math.PI);  // Start point
ctx.arc(end.x, end.y, 5, 0, 2 * Math.PI);      // End point
ctx.fill();
// Control points
ctx.fillStyle = 'red';
ctx.beginPath();
ctx.arc(cp1.x, cp1.y, 5, 0, 2 * Math.PI);  // Control point one
ctx.arc(cp2.x, cp2.y, 5, 0, 2 * Math.PI);  // Control point two
ctx.fill();
					

结果

在此范例中， control points are red 和 start and end points are blue .

A simple Bézier curve

This example draws a simple Bézier curve using bezierCurveTo() .

HTML

<canvas id="canvas"></canvas>
					

JavaScript

The curve begins at the point specified by moveTo() : (30, 30). The first control point is placed at (120, 160), and the second at (180, 10). The curve ends at (220, 140).

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
ctx.beginPath();
ctx.moveTo(30, 30);
ctx.bezierCurveTo(120,160, 180,10, 220,140);
ctx.stroke();
					

结果

规范

规范	状态	注释
HTML 实时标准 The definition of 'CanvasRenderingContext2D.beziercurveto' in that specification.	实时标准

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
bezierCurveTo	Chrome 1	Edge 12	Firefox 1.5	IE 9	Opera 11.6	Safari 2	WebView Android 1	Chrome Android 18	Firefox Android 4	Opera Android 12	Safari iOS 1	Samsung Internet Android 1.0

图例

完整支持

完整支持

另请参阅

• The interface defining this method: CanvasRenderingContext2D
• Wikipedia article on Bézier curves

元数据

• 最后修改： 2019 年 3 月 23 日

相关话题

1. CanvasRenderingContext2D
2. 特性

   1. canvas
   2. currentTransform
   3. direction
   4. fillStyle
   5. filter
   6. font
   7. globalAlpha
   8. globalCompositeOperation
   9. imageSmoothingEnabled
   10. imageSmoothingQuality
   11. lineCap
   12. lineDashOffset
   13. lineJoin
   14. lineWidth
   15. miterLimit
   16. shadowBlur
   17. shadowColor
   18. shadowOffsetX
   19. shadowOffsetY
   20. strokeStyle
   21. textAlign
   22. textBaseline
3. 方法

   1. addHitRegion()
   2. arc()
   3. arcTo()
   4. beginPath()
   5. bezierCurveTo()
   6. clearHitRegions()
   7. clearRect()
   8. clip()
   9. closePath()
   10. createImageData()
   11. createLinearGradient()
   12. createPattern()
   13. createRadialGradient()
   14. drawFocusIfNeeded()
   15. drawImage()
   16. drawWidgetAsOnScreen()
   17. drawWindow()
   18. ellipse()
   19. fill()
   20. fillRect()
   21. fillText()
   22. getImageData()
   23. getLineDash()
   24. getTransform()
   25. isPointInPath()
   26. isPointInStroke()
   27. lineTo()
   28. measureText()
   29. moveTo()
   30. putImageData()
   31. quadraticCurveTo()
   32. rect()
   33. removeHitRegion()
   34. resetTransform()
   35. restore()
   36. rotate()
   37. save()
   38. scale()
   39. scrollPathIntoView()
   40. setLineDash()
   41. setTransform()
   42. stroke()
   43. strokeRect()
   44. strokeText()
   45. transform()
   46. translate()