如何在Flutter中更改PopupMenuItem的背景颜色

Question

如何在flutter中更改PopupMenuItem的背景颜色？

现在我只是改变 PopupMenuItem 子项的颜色，结果是这样的：

这是代码：

PopupMenuButton<int>(
        onSelected: (value) {
          // TODO: Implement onSelect
        },
        offset: Offset(50, 50),
        itemBuilder: (context) => [
          PopupMenuItem(
            value: 1,
            child: Container(
              height: double.infinity,
              width: double.infinity,
              color: Colors.greenAccent,  // i use this to change the bgColor color right now
              child: Row(
                mainAxisAlignment: MainAxisAlignment.end,
                children: <Widget>[
                  Icon(Icons.check),
                  SizedBox(width: 10.0),
                  Text("Konfirmasi Update"),
                  SizedBox(width: 10.0),
                ],
              ),
            ),
          ),

我想要的是更改“Konfirmasi Update”选项的背景颜色，如上图所示，颜色在选项外留下白色区域。

如何完全更改 PopupMenuItem 背景颜色，而不留下 PopupMenuItem 外部的白色区域？

Answer 1

另一种选择是从 PopupMenuItem 继承。

要使用，只需更改 CustomPopupMenuItem 的 PopupMenuButton 并设置颜色。

import 'package:flutter/material.dart';

class CustomPopupMenuItem<T> extends PopupMenuItem<T> {
  final Color color;

  const CustomPopupMenuItem({
    Key key,
    T value,
    bool enabled = true,
    Widget child,
    this.color,
  }) : super(key: key, value: value, enabled: enabled, child: child);

  @override
  _CustomPopupMenuItemState<T> createState() => _CustomPopupMenuItemState<T>();
}

class _CustomPopupMenuItemState<T> extends PopupMenuItemState<T, CustomPopupMenuItem<T>> {
  @override
  Widget build(BuildContext context) {
    return Container(
      child: super.build(context),
      color: widget.color,
    );
  }
}

Answer 2

无法开箱即用地使用PopupMenuButton和PopupMenuItem小部件，因为如果您检查源代码，就会发现垂直和水平填充的硬编码值。

我修改了文件的代码popup_menu.dart，特别是这些值：

const double _kMenuVerticalPadding = 0.0;//8.0;
const double _kMenuHorizontalPadding = 0.0;//16.0;

如果您想让它工作，请将此文件下载到您的项目：https://gist.github.com/diegovoper/995f1e03ef225edc64e06525dc024b01

将该文件导入到您的项目中并添加别名：

import 'your_project/my_popup_menu.dart' as mypopup;

用法：

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: mypopup.PopupMenuButton<int>(
          elevation: 20,
          onSelected: (value) {
            // TODO: Implement onSelect
          },
          offset: Offset(50, 50),
          itemBuilder: (context) => [
            mypopup.PopupMenuItem(
              value: 1,
              child: Container(
                height: double.infinity,
                width: double.infinity,
                color: Colors
                    .greenAccent, // i use this to change the bgColor color right now
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.end,
                  children: <Widget>[
                    Icon(Icons.check),
                    SizedBox(width: 10.0),
                    Text("Konfirmasi Update"),
                    SizedBox(width: 10.0),
                  ],
                ),
              ),
            ),
            mypopup.PopupMenuItem(
              value: 1,
              child: Container(
                height: double.infinity,
                width: double.infinity,
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.end,
                  children: <Widget>[
                    Icon(Icons.check),
                    SizedBox(width: 10.0),
                    Text("Revisi Update"),
                    SizedBox(width: 10.0),
                  ],
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }

结果