Flutter Hintstyle副本

Question

我想构建一个像我上传的图像这样的textfield 我想在不触摸源文件的情况下更改Textfield上的属性。 它在input_decorator

final Widget? hint = decoration!.hintText == null ? null : AnimatedOpacity(
      opacity: (isEmpty && !_hasInlineLabel) ? 1.0 : 0.0,
      duration: _kTransitionDuration,
      curve: _kTransitionCurve,
      alwaysIncludeSemantics: true,
      child: Text(
        decoration!.hintText!,
        style: hintStyle,
        textDirection: decoration!.hintTextDirection,
        overflow: TextOverflow.ellipsis,
        textAlign: textAlign,
        maxLines: decoration!.hintMaxLines,
      ),
    );

中