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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 .shadowOffsetY property of the Canvas 2D API specifies the distance that shadows will be offset vertically.

注意： Shadows are only drawn if the shadowColor property is set to a non-transparent value. One of the shadowBlur , shadowOffsetX ，或 shadowOffsetY properties must be non-zero, as well.

句法

ctx.shadowOffsetY = offset;
					

offset

A float specifying the distance that shadows will be offset vertically. Positive values are down, and negative are up. The default value is 0 (no vertical offset). Infinity and NaN values are ignored.

范例

Moving a shadow vertically

This example adds a blurred shadow to a rectangle. The shadowColor property sets its color, shadowOffsetY sets its offset 25 units towards the bottom, and shadowBlur gives it a blur level of 10.

HTML

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

JavaScript

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
// Shadow
ctx.shadowColor = 'red';
ctx.shadowOffsetY = 25;
ctx.shadowBlur = 10;
// Rectangle
ctx.fillStyle = 'blue';
ctx.fillRect(20, 20, 150, 80);
					

结果

规范

规范	状态	注释
HTML 实时标准 The definition of 'CanvasRenderingContext2D.shadowOffsetY' 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
shadowOffsetY	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes

图例

完整支持

完整支持

另请参阅

• The interface defining this property: CanvasRenderingContext2D
• CanvasRenderingContext2D.shadowOffsetX
• CanvasRenderingContext2D.shadowColor
• CanvasRenderingContext2D.shadowBlur

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()