【Flutter入门到进阶】Flutter基础篇---弹窗Dialog
1 AlertDialog
1.1 说明
最简单的方案是利用AlertDialog组件构建一个弹框
1.2 示例
void alertDialog(BuildContext context) async {var result = await showDialog(barrierDismissible: false, //表示点击灰色背景的时候是否消失弹出框context: context,builder: (context) {return AlertDialog(title: const Text("提示信息!"),content: const Text("您确定要删除吗"),actions: [TextButton(onPressed: () {print("ok");Navigator.of(context).pop("ok"); //点击按钮让AlertDialog消失},child: const Text("确定")),TextButton(onPressed: () {print("cancel");Navigator.of(context).pop("取消");},child: const Text("取消"))],);});print("-----------");print(result);
}2 SimpleDialog
2.1 说明
通过SimpleDialog构建一个选择框
2.2 示例
void simpleDialog(BuildContext context) async {var result = await showDialog(barrierDismissible: false, //表示点击灰色背景的时候是否消失弹出框context: context,builder: (context) {return SimpleDialog(title: const Text("请选择语言"),children: [SimpleDialogOption(onPressed: () {print("汉语");Navigator.pop(context, "汉语");},child: const Text("汉语"),),const Divider(),SimpleDialogOption(onPressed: () {print("英语");Navigator.pop(context, "英语");},child: const Text("英语"),),const Divider(),SimpleDialogOption(onPressed: () {print("日语");Navigator.pop(context, "日语");},child: const Text("日语"),),const Divider(),],);});print("-----------");print(result);
}
3 自定义Flutter Dialog
3.1 说明
通过继承Dialog实现自定义的弹窗
3.2 示例
// 自定义dialog
class MyDialog extends Dialog {String title;String content;Function()? onClosed;MyDialog({Key? key, required this.title,requiredthis.onClosed,this.content=""}) : super(key: key);@overrideWidget build(BuildContext context) {return Material(type: MaterialType.transparency,child: Center(child: Container(height: 300,width: 300,color: Colors.white,child: Column(children: <Widget>[Padding(padding: const EdgeInsets.all(10),child: Stack(children: <Widget>[Align(alignment: Alignment.center,child: Text(title),),Align(alignment: Alignment.centerRight,child: InkWell(onTap: onClosed,child: const Icon(Icons.close),),)],),),const Divider(),Container(padding: const EdgeInsets.all(10),width: double.infinity,child: Text(content,textAlign: TextAlign.left),)],),)),);}
}4 Flutter Toast
4.1 第三方框架
4.1.1 说明
https://pub.dev/packages/fluttertoast
4.1.2 示例
Fluttertoast.showToast(msg: "提示信息",toastLength: Toast.LENGTH_LONG, //值针对 android 平台timeInSecForIosWeb: 1, //提示时间 针对ios 和 webbackgroundColor: Colors.black26, //背景颜色textColor: Colors.white, //文本颜色fontSize: 16.0 //文本字体大小);4.2 自定义
4.2.1 说明
所谓toast框其实就是在图层的最上面一层插入一个显示图层，在Flutter中利用OverLayEntry构建图层，然后通过Overlay进行插入
4.2.2 示例
import 'package:flutter/material.dart';class Toast {static var _lastMsg;static int _lastShowms = 0;static get flag => true;static OverlayEntry? entry;static Future _show(BuildContext context, String msg, int duration) {entry = OverlayEntry(builder: (BuildContext context) => Positioned(//top值，可以改变这个值来改变toast在屏幕中的位置top: MediaQuery.of(context).size.height.toDouble() * 0.5,child: Container(alignment: Alignment.center,width: MediaQuery.of(context).size.width,child: Padding(padding: const EdgeInsets.symmetric(horizontal: 10.0),child: ToastWidget(msg: "test",duration: duration,),// child: _buildToastWidget(context,msg),)),),);///往Overlay中插入插入OverlayEntryOverlay.of(context)?.insert(entry!);///两秒后，移除Toast// Future result = Future.delayed(Duration(milliseconds: duration)).then((value) {// print("移除....");// entry!.remove();// });// return result;return Future(() => 0);}//toast UI绘制static _buildToastWidget(context, String msg) {return Row(mainAxisSize: MainAxisSize.min,children: [Container(alignment: Alignment.center,decoration: BoxDecoration(borderRadius: BorderRadius.circular(12.0),shape: BoxShape.rectangle,color: Colors.black45,),child: Padding(padding: const EdgeInsets.all(10),child: Text(msg,style: const TextStyle(color: Colors.white,decoration: TextDecoration.none,fontSize: 14)),))],);}//处理重复多次点击static void _handleDuplicateAndShow(String message, BuildContext context, int duration) {if (_lastMsg == message) {//相同信息内容int currentms = DateTime.now().millisecondsSinceEpoch;int interval = currentms - _lastShowms;if (interval > duration) {//大于时间间隔 可以显示_show(context, message, duration);_lastShowms = currentms;}} else {_show(context, message, duration);_lastMsg = message;}}/// 提示static void showInfo(String message, {required BuildContext context, int duration = 2000}) {_handleDuplicateAndShow(message, context, duration);}
}class ToastWidget extends StatefulWidget {String msg;int duration;ToastWidget({super.key,required this.msg,required this.duration});@overrideState<ToastWidget> createState() => _ToastState();
}class _ToastState extends State<ToastWidget> with SingleTickerProviderStateMixin {late AnimationController _controller;@overridevoid initState() {_controller = AnimationController(vsync: this,duration: const Duration(seconds: 1),);}@overridevoid dispose() {_controller.dispose();super.dispose();}@overrideWidget build(BuildContext context) {//启动正序一次Future((){print("启动动画...");_controller.forward();}).then((value) {//结束倒叙一次Future.delayed(Duration(milliseconds: widget.duration-2)).then((value) async{print("启动结束动画...");await _controller.reverse();//移除图层Toast.entry!.remove();print("移除图层...");});});print("构建组件");return Center(child: FadeTransition(opacity: _controller,child:Row(mainAxisSize: MainAxisSize.min,children: [Container(alignment: Alignment.center,decoration: BoxDecoration(borderRadius: BorderRadius.circular(12.0),shape: BoxShape.rectangle,color: Colors.black45,),child: Padding(padding: const EdgeInsets.all(10),child: Text(widget.msg,style: const TextStyle(color: Colors.white,decoration: TextDecoration.none,fontSize: 14)),))],),),);}
}