添加插件 - 启动APP 音乐后台播放

flutter 插件编写

计划编写一个 flutter 关于音视频控制的插件,借此学习一下插件的编写

第一步 开始创建一个插件

1. 启动 Android Studio
2. 选择 New Flutter Project 创建插件 (md 没有这个选项了... 什么破文案 )

重来 第一步

ios 项目中创建插件类 接口文件

//
//  FlutterAVAudioSessionPlugin.h
//  Runner
//
//  Created by liuliang on 2022/11/11.
//

#import 
#import 

NS_ASSUME_NONNULL_BEGIN

@interface FlutterAVAudioSessionPlugin : NSObject
+ (void)registerWithRegistrar:(NSObject *)registrar;
@end

NS_ASSUME_NONNULL_END

ios 实现类

//
//  FlutterAVAudioSessionPlugin.m
//  Runner
//
//  Created by liuliang on 2022/11/11.
//

#import "FlutterAVAudioSessionPlugin.h"
#import 

static FlutterMethodChannel *methodChannel;

@implementation FlutterAVAudioSessionPlugin

+ (void)registerWithRegistrar:(nonnull NSObject *)registrar{
   // 注册通道 启动单利
    FlutterMethodChannel* channel = [FlutterMethodChannel methodChannelWithName:@"io.flutter.plugins.avaudio.session" binaryMessenger:[registrar messenger]];
    methodChannel = channel;
    FlutterAVAudioSessionPlugin* instance = [[FlutterAVAudioSessionPlugin alloc] init];
    [registrar addMethodCallDelegate:instance channel:channel];
}

- (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
  // 如果包含有参数 这样取参
  /**
        NSString *title = call.arguments[@"title"];
        NSString *icon = call.arguments[@"icon"];
        NSString *url = call.arguments[@"url"];
   */

  // 监听方法 ,** 注意方法命名 驼峰命名法
    if ([call.method isEqualToString:@"backAvaudioSession"]) {
        [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback withOptions:AVAudioSessionCategoryOptionMixWithOthers error:nil];
    }else if ([call.method isEqualToString:@"endBackAvaudioSession"]) {
        [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback withOptions:AVAudioSessionCategoryOptionMixWithOthers error:nil];
    }else {
        result(FlutterMethodNotImplemented);
    }
    // 监听事件的回调
    NSLog(@"开启 后台播放");
}


@end

添加 插件到文件桥接文件里面 Runner-Bridging-Header

#import "FlutterAVAudioSessionPlugin.h"

注册到 appDelegate 里面

import UIKit
import Flutter
import WidgetKit
import StoreKit

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {

    @objc var allowRotation = false;


  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {

      let controller:FlutterViewController = window?.rootViewController as! FlutterViewController

      // 初始化MethodChannel，设置监听
      FlutterAVAudioSessionPlugin.register(with: self.registrar(forPlugin: "FlutterAVAudioSessionPlugin")!);
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }


    override func application(_ application: UIApplication, supportedInterfaceOrientationsFor window: UIWindow?) -> UIInterfaceOrientationMask {
        if allowRotation {
            return .all;
        }
        return .portrait;
    }

}

第几步骤来着 , 反正就是 flutter 调用吧

const MethodChannel shareChannel =
        MethodChannel('io.flutter.plugins.avaudio.session');
    shareChannel.invokeMethod('backAvaudioSession');