编写 NativeScript 插件的正确语法

Question

我正在学习 NativeScript 插件，并试图让 PubNub iOS SDK 正常工作。到目前为止（使用下面的 TypeScript），我能够成功配置、订阅频道和发布消息。我也尝试通过将“// 处理新消息...”部分也转换为 TypeScript 来接收消息，但无法使其正常工作。这个要怎么写？

目标-C：

// Initialize and configure PubNub client instance
PNConfiguration *configuration = [PNConfiguration configurationWithPublishKey:@"demo" subscribeKey:@"demo"];
self.client = [PubNub clientWithConfiguration:configuration];
[self.client addListener:self];

// Subscribe to demo channel with presence observation
[self.client subscribeToChannels: @[@"my_channel"] withPresence:YES];

// Handle new message from one of channels on which client has been subscribed.
- (void)client:(PubNub *)client didReceiveMessage:(PNMessageResult *)message {
    NSLog(@"Received message");
}

// Publish message
[self.client publish: @{@"message": @"this is my message"} 
           toChannel: @"my_channel" withCompletion:^(PNPublishStatus *status) {
}];

打字稿：

// Initialize and configure PubNub client instance
this.config = PNConfiguration.configurationWithPublishKeySubscribeKey("demo", "demo");
this.client = PubNub.clientWithConfiguration(this.config);
this.client.addListener();

// Subscribe to demo channel with presence observation
this.client.subscribeToChannelsWithPresence(channels, true);

// Handle new message from one of channels on which client has been subscribed. 
   ?

// Publish message
this.client.publishToChannelWithCompletion(msgObj, channel, function(publishStatus) {
  console.log(publishStatus.data)
})

Answer 1

看起来您在这里缺少PNObjectEventListener 代表。您应该实现委托并将其实例传递给 addListener 函数，以便在收到新消息时调用 didReceiveMessage 回调。

例如here，您可以看到核心框架如何为 TextView 实现 UITextViewDelegate，以便在更改和其他事件时通知它。

由于您使用的是 TypeScript，请为您的 PubNub 库利用 typings，以便您轻松找到正确的语法。