如何在Android設備的屏幕解鎖時重新啓動活動？

Question

我有4個活動：

• FirstActivity - 它顯示在程序的第一次運行
• MainActivity
• SeconActivity
• ThirdActivity

我想告訴FirstActivity當電源按鈕點擊並且用戶解鎖他/她的手機。但我怎麼能處理它，後顯示FirstActivity BackgroundActivity再次顯示。 我該怎麼做？

例如在MainActivity：

public boolean onKeyDown(int keyCode, KeyEvent event) { 
    if (event.getKeyCode() == KeyEvent.KEYCODE_POWER) { 
     Intent checkingIntent=new Intent(getApplicationContext(),FirstActivity.class); 
     checkingIntent.putExtra("checking",true); 
     startActivity(checkingIntent); 
     return true; 
    } 
    return super.onKeyDown(keyCode, event); 
} 

和FirstActivity

public boolean checking() { 
    checking_FOR_bankInfo= getIntent().getExtras().getBoolean("checking"); 
    if (checking_FOR_bankInfo){ 
     ... 
    } 
    return cdo_state; 
} 

Answer 1

嘗試下面的代碼在每一個活動的onPause()方法：

@Override 
protected void onPause() { 
    super.onPause(); 

    PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE); 
    boolean screenOn; 
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT_WATCH) { 
     screenOn = pm.isInteractive(); 
    } else { 
     screenOn = pm.isScreenOn(); 
    } 
    if (!screenOn) { //Screen off by lock or power 
     Intent checkingIntent = new Intent(this, FirstActivity.class); 
     checkingIntent.putExtra("checking",true); 
     checkingIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK|Intent.FLAG_ACTIVITY_CLEAR_TOP|Intent.FLAG_ACTIVITY_SINGLE_TOP); 
     startActivity(checkingIntent); 
     finish(); 
    } 
} 

Answer 2

@Override 
    protected void onStop() 
    { 
     super.onStop(); 
     Log.d(tag, "MYonStop is called"); 
     // insert here your instructions 
     // you can call new activity here. 


    } 

當按下按鈕HOME所述的onStop（）方法被調用

。