如何为小部件边框/阴影添加霓虹发光效果? [英] How to add a neon glow effect to an widget border / shadow?

问题描述

有没有办法使用颤振(带有特殊着色器的 CustomPaint 或类似的东西)来创建这样的效果?

Is there any way to create effects like these using flutter (a CustomPaint with a special shadder or something like this)?

例如.我有这个容器，我使用 CustomPainter 在上面画了一些线.我可以像图片一样使用霓虹灯效果绘制这些线条吗?Paint 类有一个着色器属性，我认为我可以设置它来实现这个目标，但我不知道如何实现.

For example. I have this container and I drew some lines on it using a CustomPainter. Could I draw these lines using a neon effect just like the pictures? The Paint class has a shader property that I thought I could set up to achieve this goal, but I don't realize how.

Container(
          color: Colors.white,
          width: 300,
          height: 300,
          child: CustomPaint(
            painter: NeonPainter(),

          ),


        ),



class NeonPainter extends CustomPainter {
  Paint neonPaint = Paint();


  NeonPainter() {
    neonPaint.color = const Color(0xFF3F5BFA);
    neonPaint.strokeWidth = 2.5;
    neonPaint.shader = /// how to create a shader or something for that?
    neonPaint.someOtherProperty///

  }

  @override
  void paint(Canvas canvas, Size size) {
    drawLine(canvas, size.width / 2 - 50, size.height / 2, size.width / 2 + 50,
        size.height / 2);
    drawLine(canvas, size.width / 2 + 50, size.height / 2, size.width / 2 + 100,
        size.height / 2 + 50);
    drawLine(canvas, size.width / 2 + 100, size.height / 2 + 50,
        size.width / 2 - 100, size.height / 2 + 50);
    drawLine(
        canvas, size.width / 2 - 100, size.height / 2 + 50, size.width / 2 - 50,
        size.height / 2);
  }

  void drawLine(canvas, double x1, double y1, double x2, double y2) {
    canvas.drawLine(Offset(x1, y1), Offset(x2, y2), neonPaint);
  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) {
    return true;
  }
}

推荐答案

你可以使用 BoxShadow 小部件.你可以设置颜色、blurRadius、SpreadRadius 和偏移来实现你想要的......

You can use BoxShadow widget.. You can set color, blurRadius, SpreadRadius and offset to achieve what you want..

请注意，在示例中我使用它来获得阴影.但是如果您正确设置属性，您可以获得发光...

Note in example I have used it to get a drop shadow.. But you can get a glow if you set the properties correctly..

 Container(
            decoration: BoxDecoration(
                borderRadius: BorderRadius.circular(50),
                boxShadow: [
                  BoxShadow(
                    color: Color(0xFF000000).withAlpha(60),
                    blurRadius: 6.0,
                    spreadRadius: 0.0,
                    offset: Offset(
                      0.0,
                      3.0,
                    ),
                  ),
                ]),

这篇关于如何为小部件边框/阴影添加霓虹发光效果?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！