最短的方法:

canvas.width += 0

如果你只使用clearRect，如果你在一个表单中提交你的图纸，你会得到一个提交而不是清除，或者可能它可以先清除，然后上传一个无效的图纸，所以你需要在函数的开头添加一个preventDefault:

   function clearCanvas(canvas,ctx) {
        event.preventDefault();
        ctx.clearRect(0, 0, canvas.width, canvas.height);
    }


<input type="button" value="Clear Sketchpad" id="clearbutton" onclick="clearCanvas(canvas,ctx);">

希望它能帮助到别人。

我总是用这个

ctx.clearRect(0, 0, canvas.width, canvas.height)
window.requestAnimationFrame(functionToBeCalled)

NOTE

结合clearRect和requestAnimationFrame允许更流畅的动画，如果这是你想要的

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>

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。

这适用于我的pieChart in chart.js

<div class="pie_nut" id="pieChartContainer">
    <canvas id="pieChart" height="5" width="6"></canvas> 
</div>

$('#pieChartContainer').html(''); //remove canvas from container
$('#pieChartContainer').html('<canvas id="pieChart" height="5" width="6"></canvas>'); //add it back to the container