PROSAGA码农传奇-html/HTML5-图像引用问题，而不是从HTML5画布导出

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    尝试从下面的代码构建。从我看到的，
     <code>
      tcanvas
    </code>
     未在您的代码中定义。
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       <pre class="snippet-code-js lang-js prettyprint-override">
        <code>
          // The Javascript code I'm trying to have the save me button to download the image:
var saveme = document.getElementById("save");
var img = document.getElementById("img");
var tcanvas = document.getElementById("tcanvas");

// Drawing something on the canvas
var ctx = tcanvas.getContext("2d");
ctx.beginPath();
ctx.arc(100, 200, 40, 0, 2 * Math.PI);
ctx.fill();
ctx.stroke();

saveme.onclick = function(event) {
  img.src = tcanvas.toDataURL();
  img.style.display = 'inline';
}
        </code>
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       <pre class="snippet-code-html lang-html prettyprint-override">
        <code>
          <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type="button" value="save me" id="save" />
<div id="shirtDiv" class="page" style="width: 530px; height: 630px; position: relative; background-color: rgb(255, 255, 255);">
  <div id="drawingArea" style="position: absolute;top: 100px;left: 160px;z-index: 10;width: 200px;height: 400px;">
    <canvas id="tcanvas" width=200 height="400" class="hover" style="-webkit-user-select: none;"></canvas>
    <img id="img" />
  </div>
</div>
        </code>
      </pre>
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