Java Truetime Android API，如何在每次打开活动时自动获取GMT、PST和设备时间的值？

我正在使用API truetime android。

我的问题是，如果我想得到GMT、PST和设备时间的值。我得按一下按钮，现在就开始计时。我不喜欢这样，我希望每当我打开那个活动时，三个GMT，PST，设备时间都已经有了值，所以我现在不需要按“获取时间”按钮获取值GMT，PST，设备时间。如何实现这一点？

这是我的密码

public class SampleActivity extends AppCompatActivity {
private Button refreshBtn;
private TextView timeGMT;
private TextView timePST;
private TextView timeDeviceTime;

   protected void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    setContentView(R.layout.sample_activity);
    setupUI();
    init(this);
    click() ;
}

public static void init(final Context context) {
(new Thread(new Runnable() {
    public void run() {
        try {
           TrueTime.build().withNtpHost("time.google.com").withLoggingEnabled(false).
           withSharedPreferencesCache(context).
           withConnectionTimeout(31428).initialize();
        } catch (IOException var2) {
            var2.printStackTrace();
        }
    }
})).start();

private void click() {
    Date trueTime;
    refreshBtn!!.setOnClickListener(View.OnClickListener {
        if (!TrueTime.isInitialized()) {
            //do nothing
        } else {
       trueTime = TrueTime.now();
       Date deviceTime = new Date();
       timeGMT.setText(formatDate(trueTime, "yyyy-MM-dd HH:mm:ss",TimeZone.getTimeZone("GMT")));
       timePST.setText(formatDate(trueTime, "yyyy-MM-dd HH:mm:ss", TimeZone.getTimeZone("GMT07:00")));
       timeDeviceTime.setText(formatDate(deviceTime, "yyyy-MM-dd HH:mm:ss",TimeZone.getTimeZone("GMT-07:00"))));
        }
    }
}
private void setupUI() {
    refreshBtn = (Button) findViewById(R.id.tt_btn_refresh);
    timeGMT = (TextView) findViewById(R.id.tt_time_gmt);
    timePST = (TextView) findViewById(R.id.tt_time_pst);
    timeDeviceTime = (TextView) findViewById(R.id.tt_time_device);
}

private String formatDate(Date :date ,String : pattern,TimeZone : timeZone){
    String format = SimpleDateFormat(pattern, Locale.ENGLISH);
    format.timeZone = timeZone;
    return format.format(date);
}

---

试试这个。您可以在onCreate中找到我的更改

public class SampleActivity extends AppCompatActivity {
private Button refreshBtn;
private TextView timeGMT;
private TextView timePST;
private TextView timeDeviceTime;

   protected void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    setContentView(R.layout.sample_activity);
    setupUI();
    init(this);
    new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
        if (TrueTime.isInitialized()) {
           trueTime = TrueTime.now();
           Date deviceTime = new Date();
           timeGMT.setText(formatDate(trueTime, "yyyy-MM-dd HH:mm:ss",TimeZone.getTimeZone("GMT")));
           timePST.setText(formatDate(trueTime, "yyyy-MM-dd HH:mm:ss", TimeZone.getTimeZone("GMT07:00")));
           timeDeviceTime.setText(formatDate(deviceTime, "yyyy-MM-dd HH:mm:ss",TimeZone.getTimeZone("GMT-07:00"))));
        }
         }
        }, 1000);
}

public static void init(final Context context) {
(new Thread(new Runnable() {
    public void run() {
        try {
           TrueTime.build().withNtpHost("time.google.com").withLoggingEnabled(false).
           withSharedPreferencesCache(context).
           withConnectionTimeout(31428).initialize();
        } catch (IOException var2) {
            var2.printStackTrace();
        }
    }
})).start();

private void click() {
    Date trueTime;
    refreshBtn!!.setOnClickListener(View.OnClickListener {
          if (!TrueTime.isInitialized()) {
            //do nothing
        } else {
       trueTime = TrueTime.now();
       Date deviceTime = new Date();
       timeGMT.setText(formatDate(trueTime, "yyyy-MM-dd HH:mm:ss",TimeZone.getTimeZone("GMT")));
       timePST.setText(formatDate(trueTime, "yyyy-MM-dd HH:mm:ss", TimeZone.getTimeZone("GMT07:00")));
       timeDeviceTime.setText(formatDate(deviceTime, "yyyy-MM-dd HH:mm:ss",TimeZone.getTimeZone("GMT-07:00"))));
        }
    }
}
private void setupUI() {
    refreshBtn = (Button) findViewById(R.id.tt_btn_refresh);
    timeGMT = (TextView) findViewById(R.id.tt_time_gmt);
    timePST = (TextView) findViewById(R.id.tt_time_pst);
    timeDeviceTime = (TextView) findViewById(R.id.tt_time_device);
}

private String formatDate(Date :date ,String : pattern,TimeZone : timeZone){
    String format = SimpleDateFormat(pattern, Locale.ENGLISH);
    format.timeZone = timeZone;
    return format.format(date);
}

---

好吧，如果我第一次打开SampleActivity，它没有显示任何内容。但是，如果我再次打开SampleActivity，它就会显示值。怎么解决？谢谢，我真的很感激。你能解释一下为什么添加处理程序会使代码工作吗？有时候在UI初始化之前会调用代码。这是延迟代码执行的一种方法。或者可以在onResume中调用无处理程序。那可能行得通。如果你觉得我的答案有用，就把我的答案标记为已接受。