Android中对手机的返回键，Home键以及多功能切换键的监听

实现原理

代码实现

// BaseActivity

import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.KeyEvent;

public abstract class BaseActivity extends AppCompatActivity {

private IntentFilter mFilter;
private Receiver mReceiver;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(getLayoutId());
initBroadcast();
initView();
initData();
}

protected void initBroadcast(){
mReceiver = new Receiver();
mFilter = new IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
registerReceiver(mReceiver, mFilter);
}

public abstract int getLayoutId();

public abstract void initView();

public abstract void initData();

/**
* 只监听不拦截返回键
*/
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
Log.i("KeyListener" , "返回键按下");
// 是否拦截事件传递
//            return true;
}
return super.onKeyDown(keyCode, event);
}

@Override
protected void onDestroy() {
super.onDestroy();
unregisterReceiver(mReceiver);
}
}
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// Receiver

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;

public class Receiver extends BroadcastReceiver {

private static final String SYSTEM_DIALOG_REASON_KEY = "reason";
private static final String HOME_KEY = "homekey";
private static final String MULTITASKING_TOGGLE_KEY = "recentapps";

@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (Intent.ACTION_CLOSE_SYSTEM_DIALOGS.equals(action)) {
String reason = intent.getStringExtra(SYSTEM_DIALOG_REASON_KEY);
if (reason != null) {
if (HOME_KEY.equals(reason)) {
Log.i("KeyListener" , "Home键按下");
} else if (MULTITASKING_TOGGLE_KEY.equals(reason)) {
Log.i("KeyListener" , "多功能返回键按下");
}
}
}
}
}
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// MainActivity

public class MainActivity extends BaseActivity {

@Override
public int getLayoutId() {
return R.layout.activity_main;
}

@Override
public void initView() {

}

@Override
public void initData() {

}
}