Android BroadcastReceiver onReceive 更新MainActivity中的TextView [英] Android BroadcastReceiver onReceive Update TextView in MainActivity

问题描述

在 MainActivity 我有一个 TextView:textV1.我在 MainActivity 中也有一个更新该文本视图的方法:

In MainActivity I have a TextView: textV1. I also have a method in MainActivity that updates that textview:

public void updateTheTextView(final String t) {
    MainActivity.this.runOnUiThread(new Runnable() {
        public void run() {
            TextView textV1 = (TextView) findViewById(R.id.textV1);
            textV1.setText(t);
        }
    });
}

在 BroadcasrReceiver 中，我需要更新 MainActivity 中 textV1 中的文本.

In a BroadcasrReceiver I need to update the text in textV1 in MainActivity.

public class NotifAlarm extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
            // other things done here like notification

            // NEED TO UPDATE TEXTV1 IN MAINACTIVITY HERE
    }
}

如何做到这一点?BroadcastReceiver 从服务运行.我无法更改此代码.我可以从 onReceive() 访问和更改 MainActivity 中的 textV1 吗?我尝试了很多事情，但都失败了.

How can this be done? The BroadcastReceiver is run from a service. This code I cannot change. Can I access and change textV1 in MainActivity from onReceive()? I've tried many things but all fail.

推荐答案

在你的 MainActivity 中初始化一个 MainActivity 类的变量，如下所示.

In your MainActivity initialize a variable of MainActivity class like below.

public class MainActivity extends Activity {
    private static MainActivity ins;
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ins = this;     
    }

    public static MainActivity  getInstace(){
        return ins;
    }

    public void updateTheTextView(final String t) {
        MainActivity.this.runOnUiThread(new Runnable() {
            public void run() {
                TextView textV1 = (TextView) findViewById(R.id.textV1);
                textV1.setText(t);
            }
        });
    }
}


public class NotifAlarm extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        try {
            MainActivity  .getInstace().updateTheTextView("String");
        } catch (Exception e) {

        }           
    }
}

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