【发布时间】：2015-01-21 07:23:53
【问题描述】：
我编写了一个程序，其中我使用Timer 并使用Toggle 状态控制该计时器。
Toggle's 默认状态为OFF，一旦我将切换状态从OFF 更改为ON Timer 开始，当我再次更改为OFF 时，它会停止Timer要求。
但是当我的Timer 是ON 并且我切换到其他活动然后再次将come back 切换到ToggleActivity 然后将切换状态从ON 更改为OFF 时，问题就开始了 - 它仍然运行Timer...
注意：当我使用finish() 或back 按下时，代替Intent 回到ToggleActivity 一切正常，但是当我使用Intent 面对这样的问题..
ToggleActivity.java：
public class ToggleActivity extends Activity implements OnCheckedChangeListener {
ToggleButton toggleButton;
TextView text;
Timer timer;
TimerTask timerTask;
final Handler handler = new Handler();
Button btnSwitchActivity;
boolean toggleState;
SharedPreferences sharedPreferences;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_toggle);
toggleButton = (ToggleButton) findViewById(R.id.toggleButton);
text = (TextView) findViewById(R.id.textView1);
btnSwitchActivity = (Button) findViewById(R.id.btnSwitchActivity);
sharedPreferences = getApplicationContext().getSharedPreferences("toggleState",0);
btnSwitchActivity.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intentSwitchActivity = new Intent(ToggleActivity.this, SwitchActivity.class);
startActivity(intentSwitchActivity);
}
});
}
@Override
public void onCheckedChanged(CompoundButton arg0, boolean isChecked) {
if(isChecked)
{
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putBoolean("toggleState", true);
editor.commit();
text.setText("ON");
startTimer();
} else
{
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putBoolean("toggleState", false);
editor.commit();
text.setText("OFF");
if (timer != null) {
timer.cancel();
timer = null;
}
}
}
public void startTimer() {
timer = new Timer();
initializeTimerTask();
timer.schedule(timerTask, 1000, 5000);
}
public void stoptimertask(View v) {
if (timer != null) {
timer.cancel();
timer = null;
}
}
public void initializeTimerTask() {
timerTask = new TimerTask() {
public void run() {
handler.post(new Runnable() {
public void run() {
Calendar calendar = Calendar.getInstance();
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd:MMMM:yyyy HH:mm:ss a");
final String strDate = simpleDateFormat.format(calendar.getTime());
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(getApplicationContext(), strDate, duration);
toast.show();
}
});
}
};
}
public void onResume() {
super.onResume();
toggleState = sharedPreferences.getBoolean("toggleState", false);
Log.v("toggleState", Boolean.toString(toggleState));
if (toggleState) {
toggleButton.setChecked(true);
text.setText("ON");
} else {
toggleButton.setChecked(false);
text.setText("OFF");
}
toggleButton.setChecked(toggleState);
toggleButton.setOnCheckedChangeListener(this);
}
@Override
protected void onPause() {
super.onPause();
toggleButton.setOnCheckedChangeListener(null);
}
}
SwitchActivity.java
public class SwitchActivity extends Activity {
Button btnToggleActivity;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_switch);
btnToggleActivity = (Button) findViewById(R.id.btnToggleActivity);
btnToggleActivity.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(SwitchActivity.this, ToggleActivity.class);
startActivity(intent);
/**
* if i use finish instead of Intent to switch to ToggleActivity
* my Timer works fine
*/
// finish
}
});
}
}
activity_toggle.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:gravity="center"
android:background="#ffffff"
android:paddingTop="@dimen/activity_vertical_margin"
android:orientation="vertical"
tools:context=".ToggleActivity" >
<ToggleButton
android:id="@+id/toggleButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/toggle_selector"
android:checked="false"
android:text=""
android:textOff=""
android:textOn="" />
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:layout_marginBottom="20dp"
android:text="@string/string_toggle_off"
android:textAppearance="?android:attr/textAppearanceMedium" />
<Button
android:id="@+id/btnSwitchActivity"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/string_btn_switch"/>
</LinearLayout>
activity_switch.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:background="#ffffff"
android:orientation="vertical" >
<Button
android:id="@+id/btnToggleActivity"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/string_btn_goback"
/>
</LinearLayout>
【问题讨论】：
-
setText的行为是否正确（即，正如您所期望的那样），还是像时间那样行为不端？ -
@NeilTownsend 检查我更新的代码和屏幕
-
你不想使用finish有什么原因吗？在没有充分理由不这样做的情况下，这似乎是正确的方法。
标签： android android-activity android-lifecycle back-stack android-togglebutton