我正在尝试创建倒计时器，即使应用程序被终止或手机关闭时也会运行。例如，假设我运行倒数计时器从5小时开始倒计时。当我关闭它时，它重置为零。我想要它，以便当我从5小时开始计算它并将我的手机转动一小时并将其重新打开时，计时器显示剩余时间为4小时。我正在研究服务和多线程，但无法生成或找到适合我的解决方案。
In Android i want to run countdown timer who can run in background also
Implementing a Count down timer using Service in the background
这是我的代码段：
start_timer.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
new AlertDialog.Builder( MainActivity.this )
.setMessage( "Are you sure you want to block the selected apps for the set amount of time?" )
.setPositiveButton( "Yeah man!", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Log.d( "AlertDialog", "Positive" );
hourint = Integer.valueOf(number_text.getText().toString());
minuteint = Integer.valueOf(minute_text.getText().toString());
secondint = Integer.valueOf(second_text.getText().toString());
Log.i("YourActivity", "Hours: " + hourint);
Log.i("YourActivity", "Minutes: " + minuteint);
Log.i("YourActivity", "Seconds: " + secondint);
totalTimeCountInMilliseconds = ((hourint*60*60) +(minuteint*60) + (secondint)) * 1000; // time count
timeBlinkInMilliseconds = 30*1000;
countDownTimer = new CountDownTimer(totalTimeCountInMilliseconds, 500) {
// 500 means, onTick function will be called at every 500 milliseconds
@Override
public void onTick(long leftTimeInMilliseconds) {
long seconds = leftTimeInMilliseconds / 1000;
mSeekArc.setVisibility(View.INVISIBLE);
start_timer.setVisibility(View.INVISIBLE);
block_button1.setVisibility(View.INVISIBLE);
if ( leftTimeInMilliseconds < timeBlinkInMilliseconds ) {
// textViewShowTime.setTextAppearance(getApplicationContext(), R.style.blinkText);
// change the style of the textview .. giving a red alert style
if ( blink ) {
number_text.setVisibility(View.VISIBLE);
minute_text.setVisibility(View.VISIBLE);
second_text.setVisibility(View.VISIBLE);
// if blink is true, textview will be visible
} else {
number_text.setVisibility(View.INVISIBLE);
minute_text.setVisibility(View.INVISIBLE);
second_text.setVisibility(View.INVISIBLE);
}
blink = !blink; // toggle the value of blink
}
second_text.setText(String.format("%02d", seconds % 60));
minute_text.setText(String.format("%02d", (seconds / 60) % 60));
number_text.setText(String.format("%02d", seconds / 3600)); // format the textview to show the easily readable format
}
@Override
public void onFinish() {
// this function will be called when the timecount is finished
//textViewShowTime.setText("Time up!");
number_text.setVisibility(View.VISIBLE);
minute_text.setVisibility(View.VISIBLE);
second_text.setVisibility(View.VISIBLE);
mSeekArc.setVisibility(View.VISIBLE);
start_timer.setVisibility(View.VISIBLE);
block_button1.setVisibility(View.VISIBLE);
}
}.start();
}
})
.setNegativeButton( "Nope!", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Log.d( "AlertDialog", "Negative" );
dialog.cancel();
}
} )
.show();
我如何实现这一点以及我必须对代码进行哪些修改？
编辑：这是我的完整代码：
编辑2：此处是修订后的代码：
我的应用无法启动。我没有收到任何logcat声明，所以我不知道该怎么做......
答案 0 :(得分：2)
在输入倒计时后，计算倒计时结束的时间并将其写入持久存储。然后，只要应用程序重新启动，请阅读该时间并计算从现在开始剩余的时间。
答案 1 :(得分：0)
我认为任何人都有同样的问题;）
这是检索onCreate
中类顶部的SharedPreferencesstartimerPreferences = getPreferences(MODE_APPEND);
Date startDate = new Date(startimerPreferences.getLong("time", 0));
timerstarted = startDate.getTime();
Log.e("This is the start time!!!!!: ", timerstarted + "");
endTimerPreferences = getPreferences(MODE_APPEND);
Date endDate = new Date(endTimerPreferences.getLong("time", 0));
timerends = endDate.getTime();
Log.e("This is the end time!!!!!: ", timerends + "");
Date openagain = new Date(System.currentTimeMillis());
reopened = openagain.getTime();
如果还有剩余时间，则启动剩余时间的计时器：
if(timerstarted > 0)
{
if(reopened <timerends){
//start countdown timer with new time.
//set countdowntime to timerends-reopen.
newtotalTimeCountInMilliseconds = timerends-reopened;
countDownTimer = new CountDownTimer(newtotalTimeCountInMilliseconds, 500) {
// 500 means, onTick function will be called at every 500 milliseconds
@Override
public void onTick(long leftTimeInMilliseconds) {
long seconds = leftTimeInMilliseconds / 1000;
mSeekArc.setVisibility(View.INVISIBLE);
start_timer.setVisibility(View.INVISIBLE);
block_button1.setVisibility(View.INVISIBLE);
if (leftTimeInMilliseconds < timeBlinkInMilliseconds) {
// textViewShowTime.setTextAppearance(getApplicationContext(), R.style.blinkText);
// change the style of the textview .. giving a red alert style
if (blink) {
number_text.setVisibility(View.VISIBLE);
minute_text.setVisibility(View.VISIBLE);
second_text.setVisibility(View.VISIBLE);
// if blink is true, textview will be visible
} else {
number_text.setVisibility(View.INVISIBLE);
minute_text.setVisibility(View.INVISIBLE);
second_text.setVisibility(View.INVISIBLE);
}
blink = !blink; // toggle the value of blink
}
second_text.setText(String.format("%02d", seconds % 60));
minute_text.setText(String.format("%02d", (seconds / 60) % 60));
number_text.setText(String.format("%02d", seconds / 3600)); // format the textview to show the easily readable format
}
@Override
public void onFinish() {
// this function will be called when the timecount is finished
//textViewShowTime.setText("Time up!");
number_text.setVisibility(View.VISIBLE);
minute_text.setVisibility(View.VISIBLE);
second_text.setVisibility(View.VISIBLE);
mSeekArc.setVisibility(View.VISIBLE);
start_timer.setVisibility(View.VISIBLE);
block_button1.setVisibility(View.VISIBLE);
}
}.start();
}
}
以下是用户提交操作的初始计时器。我将当前时间和结束时间提交并保存在SharedPreferences中。
start_timer.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
new AlertDialog.Builder( MainActivity.this )
.setMessage( "Are you sure you want to block the selected apps for the set amount of time?" )
.setPositiveButton("Yeah man!", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Log.d("AlertDialog", "Positive");
hourint = Integer.valueOf(number_text.getText().toString());
minuteint = Integer.valueOf(minute_text.getText().toString());
secondint = Integer.valueOf(second_text.getText().toString());
Log.i("YourActivity", "Hours: " + hourint);
Log.i("YourActivity", "Minutes: " + minuteint);
Log.i("YourActivity", "Seconds: " + secondint);
Date currenttime = new Date(System.currentTimeMillis());
timerstarted = currenttime.getTime();
Log.e("This is the current time: ", timerstarted + "");
startimerPreferences = getPreferences(MODE_APPEND);
SharedPreferences.Editor starteditor = startimerPreferences.edit();
starteditor.putLong("time", timerstarted);
starteditor.commit();
Date endtime = new Date(System.currentTimeMillis());
timerends = endtime.getTime() + (((hourint * 60 * 60) + (minuteint * 60) + (secondint)) * 1000);
Log.e("This is the end time: ", timerends + "");
endTimerPreferences = getPreferences(MODE_APPEND);
SharedPreferences.Editor endeditor = endTimerPreferences.edit();
endeditor.putLong("time", timerends);
endeditor.commit();
totalTimeCountInMilliseconds = (((hourint * 60 * 60) + (minuteint * 60) + (secondint)) * 1000); // time count
timeBlinkInMilliseconds = 30 * 1000;
countDownTimer = new CountDownTimer(totalTimeCountInMilliseconds, 500) {
// 500 means, onTick function will be called at every 500 milliseconds
@Override
public void onTick(long leftTimeInMilliseconds) {
long seconds = leftTimeInMilliseconds / 1000;
mSeekArc.setVisibility(View.INVISIBLE);
start_timer.setVisibility(View.INVISIBLE);
block_button1.setVisibility(View.INVISIBLE);
if (leftTimeInMilliseconds < timeBlinkInMilliseconds) {
// textViewShowTime.setTextAppearance(getApplicationContext(), R.style.blinkText);
// change the style of the textview .. giving a red alert style
if (blink) {
number_text.setVisibility(View.VISIBLE);
minute_text.setVisibility(View.VISIBLE);
second_text.setVisibility(View.VISIBLE);
// if blink is true, textview will be visible
} else {
number_text.setVisibility(View.INVISIBLE);
minute_text.setVisibility(View.INVISIBLE);
second_text.setVisibility(View.INVISIBLE);
}
blink = !blink; // toggle the value of blink
}
second_text.setText(String.format("%02d", seconds % 60));
minute_text.setText(String.format("%02d", (seconds / 60) % 60));
number_text.setText(String.format("%02d", seconds / 3600)); // format the textview to show the easily readable format
}
@Override
public void onFinish() {
// this function will be called when the timecount is finished
//textViewShowTime.setText("Time up!");
number_text.setVisibility(View.VISIBLE);
minute_text.setVisibility(View.VISIBLE);
second_text.setVisibility(View.VISIBLE);
mSeekArc.setVisibility(View.VISIBLE);
start_timer.setVisibility(View.VISIBLE);
block_button1.setVisibility(View.VISIBLE);
}
}.start();
}
})
.setNegativeButton("Nope!", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Log.d("AlertDialog", "Negative");
dialog.cancel();
}
})
.show();