尝试使用javascript确定canvas是否为空
尝试使用javascript确定canvas是否为空
提问于 2018-08-14 05:51:40
我使用的解决方案来自：How to check if a canvas is blank?，但它不起作用。我的空白画布URL与新创建的画布URL不匹配，我找不到原因。它们是相同的尺寸和所有东西，但是它们的.toDataURL返回不同的东西，所以我没有办法判断它是否被绘制了。下面是我在空白画布上执行.toDataURL和在新创建的画布上执行.toDataURL时发生的情况的示例，您可以看到，随着您的继续，它们会有所不同。
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function isCanvasBlank(canvas) {
var blank = document.createElement('canvas');
blank.width = canvas.width;
blank.height = canvas.height;
return canvas.toDataURL() == blank.toDataURL();
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/51831079
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