android - 从广播接收器调用 SetContentView()

Question

在我的应用程序中有两个类，一个是 InternetActivity，它只扩展 Activity 并将 contentview 设置为 main。和扩展广播接收器的 MyClass。

我在 main.xml 文件中有 2 个 TextView 和 2 个 WIFI 和 GPRS 的 ImageView。当连接性发生变化时，将调用广播接收器，并根据启用的内容和未启用的内容设置 TextView 和 ImageView 的可见性。但它只显示图像而不是变化。这是 MyClass.java 文件。我该怎么做？？

public class MyClass extends BroadcastReceiver {

private static ImageView wifi_image, gprs_image;
private static TextView wifi_text, gprs_text;

@Override
public void onReceive(Context context, Intent intent) {

    Log.i("IntrntActivity", "Broadcast message receivved");

    LinearLayout layout = new LinearLayout(context);
    LinearLayout.LayoutParams params = new LayoutParams(
            LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);

    View view = View.inflate(context, R.layout.main, layout);

    wifi_image = (ImageView) view.findViewById(R.id.wifi_image);
    gprs_image = (ImageView) view.findViewById(R.id.gprs_image);

    wifi_text = (TextView) view.findViewById(R.id.wifi_text);
    gprs_text = (TextView) view.findViewById(R.id.gprs_text);

    wifi_image.setVisibility(View.GONE);
    wifi_text.setVisibility(View.GONE);
    gprs_image.setVisibility(View.GONE);
    gprs_text.setVisibility(View.GONE);

    ConnectivityManager cm = (ConnectivityManager) context
            .getSystemService(context.CONNECTIVITY_SERVICE);
    NetworkInfo WIFI = cm.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
    NetworkInfo Mobile = cm.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);

    if (!WIFI.isConnected() && WIFI.isAvailable()) {
        Toast.makeText(context, "WIFI is available but not connected",
                Toast.LENGTH_LONG).show();
    }

    if (cm.getNetworkInfo(ConnectivityManager.TYPE_WIFI).isAvailable()) {
        wifi_image.setVisibility(View.VISIBLE);
        wifi_text.setVisibility(View.VISIBLE);

    }

    if (Mobile.isConnected()) {
        gprs_image.setVisibility(View.VISIBLE);
        gprs_text.setVisibility(View.VISIBLE);
        Log.i("IntrntActivity", "Mobile isConnected");

        // Toast.makeText(context,"GPRS is available",
        // Toast.LENGTH_LONG).show();
    }

    if (!Mobile.isConnected()) {
        gprs_image.setVisibility(View.GONE);
        gprs_text.setVisibility(View.GONE);
        Log.i("IntrntActivity", "Mobile is Not Connected");
        // Toast.makeText(context,"GPRS is available",
        // Toast.LENGTH_LONG).show();
    }


}

}

P.S :它正确进入 Mobile.isConnected() 和 !Mobile.isConnected() 并在日志文件中显示它，但它的可见性没有改变。Am我没有正确设置 View ？是否可以从此广播接收器调用 setContentView(view)？

Answer 1

您需要将接收器放入 InternetActivity 类，在那里注册并使用已经定义的局部变量。您无需创建单独的公共(public) BroadcastReceiver 实现，只需创建一个本地实现即可。

像这样:

import android.content.BroadcastReceiver;
import android.content.Context;

public class InternetActivity extends Activity {

    private ImageView image;
    private TextView text;

    private BroadcastReceiver reciever = new BroadcastReceiver(){
        @Override
        public void onReceive(Context context, Intent intent) {
           // do all the checking
           // interact with image and text
        }    
    };
    @Override
    public void onCreate(Bundle state) {
        setContentView(R.layout.....);
        // fill in image and text variables
    }
    @Override
    public void onStart() {
        registerReceiver(receiver, /* your intent filter here */);
    }
    @Override
    public void onStop() {
        unregisterReceiver(receiver);
    }
}