Flutter开发之——IOSView

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  • Dart:2.13.4

  • Intellij:Community 2021.1

三 Intellij创建Flutter应用


  • 依次点击:File——>New——>Project——>Flutter项目

  • 设置项目名称及存储位置,开发语言及适用平台

  • 创建完成后的项目结构如图所示

三 Flutter中嵌入IOS自定义View


3.1 将项目使用Xcode打开

  • 在项目上右键,Flutter——>Open IOS module in Xcode

  • 打开后的项目目录结构如图所示

3.2 创建IOS自定义View(MyFlutterView)

import Foundation

import Flutter

class MyFlutterView: NSObject,FlutterPlatformView {

let label = UILabel()

init(_ frame: CGRect,viewID: Int64,args :Any?,messenger :FlutterBinaryMessenger) {

label.text = "我是 iOS View"

}

func view() -> UIView {

return label

}

}

3.3 MyFlutterViewFactory

import Foundation

import Flutter

class MyFlutterViewFactory: NSObject,FlutterPlatformViewFactory {

var messenger:FlutterBinaryMessenger

init(messenger:FlutterBinaryMessenger) {

self.messenger = messenger

super.init()

}

func create(withFrame frame: CGRect, viewIdentifier viewId: Int64, arguments args: Any?) -> FlutterPlatformView {

return MyFlutterView(frame,viewID: viewId,args: args,messenger: messenger)

}

func createArgsCodec() -> FlutterMessageCodec & NSObjectProtocol {

return FlutterStandardMessageCodec.sharedInstance()

}

}

3.4 在 AppDelegate 中注册

import UIKit

import Flutter

@UIApplicationMain

@objc class AppDelegate: FlutterAppDelegate {

override func application(

_ application: UIApplication,

didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?

) -> Bool {

GeneratedPluginRegistrant.register(with: self)

let registrar:FlutterPluginRegistrar = self.registrar(forPlugin: "plugins.flutter.io/custom_platform_view_plugin")!

let factory = MyFlutterViewFactory(messenger: registrar.messenger())

registrar.register(factory, withId: "plugins.flutter.io/custom_platform_view")

return super.application(application, didFinishLaunchingWithOptions: launchOptions)

}

}

说明:

  • plugins.flutter.io/custom_platform_view ,这个字符串在 Flutter 中需要与其保持一致

3.5 编辑Flutter页面

在Intellij页面中编辑main.dart

import 'package:flutter/foundation.dart';

import 'package:flutter/material.dart';

void main() {

runApp(PlatformViewDemo());

}

class PlatformViewDemo extends StatelessWidget {

@override

Widget build(BuildContext context) {

Widget? platformView() {

if (defaultTargetPlatform == TargetPlatform.android) {

return AndroidView(

viewType: 'plugins.flutter.io/custom_platform_view',

);

} else if (defaultTargetPlatform == TargetPlatform.iOS) {

return UiKitView(

viewType: 'plugins.flutter.io/custom_platform_view',

);

}

}

return MaterialApp(

home: Scaffold(

appBar: AppBar(

title: Text("Platform"),

),

body: Center(

child: platformView(),

),

),

);

}

}

3.6 效果图

四 Flutter中嵌入IOS自定义View时设置初始化参数


4.1 Flutter 端修改如下

UiKitView(

viewType: 'plugins.flutter.io/custom_platform_view',

creationParams: {'text': 'Flutter传给IOSTextView的参数'},

creationParamsCodec: StandardMessageCodec(),

)

  • creationParams :传递的参数,插件可以将此参数传递给 AndroidView 的构造函数。

  • creationParamsCodec :将 creationParams 编码后再发送给平台侧,它应该与传递给构造函数的编解码器匹配。值的范围

  • StandardMessageCodec

  • JSONMessageCodec

  • StringCodec

  • BinaryCodec

4.2 IOS自定义View接受参数

import Foundation

import Flutter

class MyFlutterView: NSObject,FlutterPlatformView {

let label = UILabel()

init(_ frame: CGRect,viewID: Int64,args :Any?,messenger :FlutterBinaryMessenger) {

super.init()

if(args is NSDictionary){

let dict = args as! NSDictionary

label.text = dict.value(forKey: "text") as! String

}

}

func view() -> UIView {

return label

}

}

4.3 效果图

五 Flutter 向 iOS View 发送消息


5.1 Flutter 端,创建 MethodChannel 用于通信(Intellij端修改)

import 'package:flutter/foundation.dart';

import 'package:flutter/material.dart';

import 'package:flutter/services.dart';

void main() {

runApp(PlatformViewDemo());

}

class PlatformViewDemo extends StatefulWidget {

@override

_PlatformViewDemoState createState() => _PlatformViewDemoState();

}

class _PlatformViewDemoState extends State {

static const platform =

const MethodChannel('com.example.flutterios.MyFlutterView');

@override

Widget build(BuildContext context) {

Widget? platformView() {

if (defaultTargetPlatform == TargetPlatform.android) {

return AndroidView(

viewType: 'plugins.flutter.io/custom_platform_view',

creationParams: {'text': 'Flutter传给AndroidTextView的参数'},

creationParamsCodec: StandardMessageCodec(),

);

} else if (defaultTargetPlatform == TargetPlatform.iOS) {

return UiKitView(

viewType: 'plugins.flutter.io/custom_platform_view',

creationParams: {'text': 'Flutter传给IOSTextView的参数'},

creationParamsCodec: StandardMessageCodec(),

);

}

}

return MaterialApp(

home: Scaffold(

appBar: AppBar(),

body: Column(children: [

RaisedButton(

child: Text('传递参数给原生View'),

onPressed: () {

platform.invokeMethod('setText', {'name': '张三', 'age': 18});

},

),

Expanded(child: Center(child: platformView())),

]),

),