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我正在使用 React Native 和Native Modules为Smart POS构建一个应用程序以使用 Java 本机功能，我需要将一张票的图片发送到打印机，我收到 HTML 代码中的票布局并需要将其转换为一个图像，为此，我在 Web 视图中呈现此 HTML 代码，然后使用画布打印到位图

问题：图像未正确渲染，宽度和高度始终等于 0

我对原生开发没有太多经验，所以我的代码有问题吗？

我的代码：

@ReactMethod
public void print() {
  Activity activity = getCurrentActivity();
  Context context = reactContext.getApplicationContext();
  String path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/DCIM/print.jpg";
  activity.runOnUiThread(new Runnable() {
    @Override
    public void run() {
      WebView wv = new WebView(context);

      wv.loadData("<html><body style='width: 300px; height: 300px'><h1 style='color: #000'>Test</h1></body></html>", "text/html", null);
    
      // mede o tamanho da webview
      wv.measure(View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED), View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));

      // define o layout da webview
      wv.layout(0, 0, wv.getMeasuredWidth(), wv.getMeasuredHeight());

      // cria um bitmap
      Bitmap bm = Bitmap.createBitmap(wv.getMeasuredWidth(), wv.getMeasuredHeight(), Bitmap.Config.ARGB_8888);

      // desenha o bitmap no canvas
      Paint paint = new Paint();
      Canvas cv = new Canvas(bm);
      int height = bm.getHeight();
      cv.drawBitmap(bm, 0, height, paint);

      wv.draw(cv);

      try {
        FileOutputStream out = new FileOutputStream(path);
        bm.compress(Bitmap.CompressFormat.JPEG, 100, out);
        out.flush();
        out.close();
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  });
}
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