function clear(context, color)
{
    var tmp = context.fillStyle;
    context.fillStyle = color;
    context.fillRect(0, 0, context.canvas.width, context.canvas.height);
    context.fillStyle = tmp;
}

现在有一个.reset()方法，它不仅会清除画布缓冲区，还会完全重置上下文的所有属性(样式等)，重置它的转换矩阵，清除它的当前子路径，清除它的状态堆栈(由save()和restore()控制)，并删除所有的剪辑区域。

context.reset();
// now 'context' is clear as new

基本上，它具有与canvas相同的效果。Width += 0，除了它更习惯。

然而，在当前的Chromium实现中，它似乎和canvas一样慢。Width += 0时，它也会生成一个新的缓冲区，而不是简单地清除前一个缓冲区(导致更多的内存垃圾)。另一个警告是，它目前只在铬浏览器中支持。 虽然要填充它，你可以去Chrome的方式

if (!CanvasRenderingContext2D.prototype.reset) {
  CanvasRenderingContext2D.prototype.reset = function() {
    this.canvas.width += 0;
  };
}
if (!OffscreenCanvasRenderingContext2D.prototype.reset) {
  OffscreenCanvasRenderingContext2D.prototype.reset = function() {
    this.canvas.width += 0;
  };
}

这里有很多很好的答案。 还有一点需要注意的是，有时候只清除部分画布也很有趣。 也就是说，“淡出”之前的图像，而不是完全擦除它。 这样可以产生很好的轨迹效果。

很容易。假设你的背景颜色是白色:

// assuming background color = white and "eraseAlpha" is a value from 0 to 1.
myContext.fillStyle = "rgba(255, 255, 255, " + eraseAlpha + ")";
myContext.fillRect(0, 0, w, h);

This is a Free hand drawing Canvas with a Clear Canvas Button. See this live example of a canvas which you can draw on and also when required clear it for redrawing clearRect() is used to delete the prersent canvas and fillRect() is used to again draw the initial canvas which was clean and had no drawings on it. var canvas = document.getElementById("canvas"), ctx = canvas.getContext("2d"), painting = false, lastX = 0, lastY = 0, lineThickness = 1; canvas.width=canvas.height = 250; ctx.fillRect(0, 0, 250, 250); canvas.onmousedown = function(e) { painting = true; ctx.fillStyle = "#ffffff"; lastX = e.pageX - this.offsetLeft; lastY = e.pageY - this.offsetTop; }; canvas.onmouseup = function(e){ painting = false; } canvas.onmousemove = function(e) { if (painting) { mouseX = e.pageX - this.offsetLeft; mouseY = e.pageY - this.offsetTop; // find all points between var x1 = mouseX, x2 = lastX, y1 = mouseY, y2 = lastY; var steep = (Math.abs(y2 - y1) > Math.abs(x2 - x1)); if (steep){ var x = x1; x1 = y1; y1 = x; var y = y2; y2 = x2; x2 = y; } if (x1 > x2) { var x = x1; x1 = x2; x2 = x; var y = y1; y1 = y2; y2 = y; } var dx = x2 - x1, dy = Math.abs(y2 - y1), error = 0, de = dy / dx, yStep = -1, y = y1; if (y1 < y2) { yStep = 1; } lineThickness = 4; for (var x = x1; x < x2; x++) { if (steep) { ctx.fillRect(y, x, lineThickness , lineThickness ); } else { ctx.fillRect(x, y, lineThickness , lineThickness ); } error += de; if (error >= 0.5) { y += yStep; error -= 1.0; } } lastX = mouseX; lastY = mouseY; } } var button=document.getElementById("clear"); button.onclick=function clearcanvas(){ canvas=document.getElementById("canvas"), ctx = canvas.getContext('2d'); ctx.clearRect(0, 0, 250, 250); canvas.width=canvas.height = 250; ctx.fillRect(0, 0, 250, 250);} #clear{border-radius:10px; font-size:8px !important; position:absolute; top:1px;} #canvas{border-radius:10px} <link href="https://www.w3schools.com/w3css/4/w3.css" rel="stylesheet"/> <button id="clear" class="w3-padding w3-xxlarge w3-pink" type="button">Clear Canvas</button> <canvas id="canvas"></canvas>

使用clearRect方法通过传递x,y坐标和画布的高度和宽度。ClearRect将清除整个画布:

canvas = document.getElementById("canvas");
ctx = canvas.getContext("2d");
ctx.clearRect(0, 0, canvas.width, canvas.height);

这是我使用的，不管边界和矩阵变换:

function clearCanvas(canvas) {
  const ctx = canvas.getContext('2d');
  ctx.save();
  ctx.globalCompositeOperation = 'copy';
  ctx.strokeStyle = 'transparent';
  ctx.beginPath();
  ctx.lineTo(0, 0);
  ctx.stroke();
  ctx.restore();
}

基本上，它保存了上下文的当前状态，并以globalCompositeOperation为copy绘制了一个透明像素。然后，恢复以前的上下文状态。