java - 多次获取非 Activity 类中的Context

Question

我正在开发一个应用程序，其中“更新程序”不断向服务器请求数据。如果它收到新数据，数据将通过 LocalBroadcast 发送到 Activity 。为此，我需要在构造函数中传递的当前上下文。此外，新数据被写入 Singleton 类(通过应用程序的运行时存储它)。

问题是，我需要为 LocalBroadcast 不断添加新的上下文，但它只在构造函数中传递一次。有人知道每次 LocalBroadcast 发送内容时如何获取当前上下文吗？

我找到了这个答案，但我总是警告不要将上下文类放入静态字段中。 (Get application context from non activity singleton class)

感谢您的阅读和每条建议。这是我的“更新程序”代码:

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.support.v4.content.LocalBroadcastManager;

import java.util.Arrays;


public class ClientUpdater extends Thread {
    ClientCommunication cComm;              //this is my class which manages the Server-Client-Communication
    Intent BroadcastIntentUpdate;           //Intent for the LocalBroadcast
    Context cntxt;                          //stores the context passed in the constructor
    GlobalClass Obj1;                       //Instance of my Singleton

    public ClientUpdater(ClientCommunication cComm, Context context) {
        this.cComm = cComm;
        this.cntxt = context;
        BroadcastIntentUpdate = new Intent("update");
    }

    public void run(){
        while(true){

            String vomS1 = cComm.sendData("updateChat" + "~" + "$empty$");      //sends an update request to the server an receives the current chat-state
            if(!vomS1.equalsIgnoreCase("timeout")){

                Obj1 = GlobalClass.getInstance();
                String[] update = GlobalClass.decode(vomS1, ";");               //decodes the receives message                  
                String[] altchat = Obj1.getChat();                              //loads the stored chat protocoll from singleton


                if(!Arrays.equals(update, altchat)){                            //if the received message has new data...

                    BroadcastIntentUpdate.putExtra("message", update);
                    //for ".getInstance(cntxt)" the current Context is always needed right?
                    LocalBroadcastManager.getInstance(cntxt).sendBroadcast(BroadcastIntentUpdate);          //...it's sent to the activity
                    Obj1.setChat(update);                                                                                           //...and stored in the singleton
                }
            }    


            try {
                sleep(500);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

    }

}

Answer 1

改变

this.cntxt = context;

至

cntxt = context.getApplicationContext();

相反。其中 cntxt 是静态上下文。它不会造成 Activity 泄漏，因为它使用应用程序上下文。

如果你了解一下Android的后台服务就更好了 https://developer.android.com/training/run-background-service/create-service.html