Flutter 渐变按钮示例

class GradientButtonWidget extends StatefulWidget {
  const GradientButtonWidget({Key? key}) : super(key: key);

  @override
  State<GradientButtonWidget> createState() {
    return GradientButtonState();
  }
}

class GradientButtonState extends State<GradientButtonWidget> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("渐变按钮"),
      ),
      body: Column(
        mainAxisSize: MainAxisSize.min,
        children: <Widget>[
          GradientButton(
            colors: const [Colors.orange, Colors.red],
            height: 50,
            onPressed: onTap,
            child: const Text("Submit"),
          ),
          GradientButton(
            colors: [Colors.lightGreen, Colors.green.shade700],
            height: 50,
            onPressed: onTap,
            child: const Text("Submit"),
          ),
          GradientButton(
            colors: [Colors.lightBlue.shade300, Colors.blueAccent],
            height: 50,
            onPressed: onTap,
            child: const Text("Submit"),
          ),
        ],
      ),
    );
  }

  void onTap() {}
}

class GradientButton extends StatelessWidget {
  const GradientButton(
      {Key? key,
      this.colors,
      this.width,
      this.height,
      this.borderRadius,
      this.onPressed,
      required this.child})
      : super(key: key);

  // 渐变色数组
  final List<Color>? colors;

  // 按钮宽高
  final double? width;
  final double? height;
  final BorderRadius? borderRadius;

  //点击回调
  final GestureTapCallback? onPressed;
  final Widget child;

  @override
  Widget build(BuildContext context) {
    ThemeData theme = Theme.of(context);
    List<Color> _colors =
        colors ?? [theme.primaryColor, theme.primaryColorDark];

    return DecoratedBox(
      decoration: BoxDecoration(
        gradient: LinearGradient(colors: _colors),
        borderRadius: borderRadius,
      ),
      child: Material(
        type: MaterialType.transparency,
        child: InkWell(
          splashColor: _colors.last,
          highlightColor: Colors.transparent,
          borderRadius: borderRadius,
          onTap: onPressed,
          child: ConstrainedBox(
            constraints: BoxConstraints.tightFor(height: height, width: width),
            child: Center(
              child: Padding(
                padding: const EdgeInsets.all(8),
                child: DefaultTextStyle(
                  style: const TextStyle(fontWeight: FontWeight.bold),
                  child: child,
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }
}