本文介绍了Android定时器Timer的停止和重启实现代码，分享给大家，具体如下：

7月份做了一个项目，利用自定义控件呈现一幅动画，当时使用定时器来控制时间，但是当停止开启时总是出现问题。一直在寻找合理的方法解决这个问题，一直没有找到，最近终于找到了合理的方法来解决这个问题。

大家如何查询有关资料，一定知道timer,timertask取消的方式是采用Timer.cancel()和mTimerTask.cancel()，可是大家发现这种发式取消后，再次开始timer时，会报错

FATAL EXCEPTION: main

Process: com.example.zhongzhi.gate_control_scheme, PID: 2472

java.lang.IllegalStateException: Timer already cancelled.

at java.util.Timer.sched(Timer.java:397)

at java.util.Timer.schedule(Timer.java:248)

at com.example.zhongzhi.gate_control_scheme.MainActivity.onClick(MainActivity.java:401)

at android.view.View.performClick(View.java:5637)

at android.view.View$PerformClick.run(View.java:22429)

at android.os.Handler.handleCallback(Handler.java:751)

at android.os.Handler.dispatchMessage(Handler.java:95)

at android.os.Looper.loop(Looper.java:154)

at android.app.ActivityThread.main(ActivityThread.java:6119)

at java.lang.reflect.Method.invoke(Native Method)

at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)

at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)

这个问题的解决采用cancle(),取消timer后，还需要清空timer。合理的代码应该是这样的：

mTimer.cancel();

mTimer = null;

mTimerTask.cancel();

mTimerTask = null;

关键的问题解决完了，下面给出我的案例代码Mainactivity.Java：

public class MainActivity extends AppCompatActivity {

private static String TAG = "TimerDemo";

private TextView mTextView = null;

private Button mButton_start = null;

private Button mButton_pause = null;

private Timer mTimer = null;

private TimerTask mTimerTask = null;

private Handler mHandler = null;

private static int count = 0;

private boolean isPause = false;

private boolean isStop = true;

private static int delay = 1000; //1s

private static int period = 1000; //1s

private static final int UPDATE_TEXTVIEW = 0;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

mTextView = (TextView)findViewById(R.id.mytextview);

mButton_start = (Button)findViewById(R.id.mybutton_start);

mButton_pause = (Button)findViewById(R.id.mybutton_pause);

mButton_start.setOnClickListener(new Button.OnClickListener() {

public void onClick(View v) {

if (isStop) {

Log.i(TAG, "Start");

} else {

Log.i(TAG, "Stop");

}

isStop = !isStop;

if (!isStop) {

startTimer();

}else {

stopTimer();

}

if (isStop) {

mButton_start.setText(R.string.start);

} else {

mButton_start.setText(R.string.stop);

}

}

});

mButton_pause.setOnClickListener(new Button.OnClickListener() {

public void onClick(View v) {

if (isPause) {

Log.i(TAG, "Resume");

} else {

Log.i(TAG, "Pause");

}

isPause = !isPause;

if (isPause) {

mButton_pause.setText(R.string.resume);

} else {

mButton_pause.setText(R.string.pause);

}

}

});

mHandler = new Handler(){

@Override

public void handleMessage(Message msg) {

switch (msg.what) {

case UPDATE_TEXTVIEW:

updateTextView();

break;

default:

break;

}

}

};

}

private void updateTextView(){

mTextView.setText(String.valueOf(count));

}

private void startTimer(){

if (mTimer == null) {

mTimer = new Timer();

}

if (mTimerTask == null) {

mTimerTask = new TimerTask() {

@Override

public void run() {

Log.i(TAG, "count: "+String.valueOf(count));

sendMessage(UPDATE_TEXTVIEW);

do {

try {

Log.i(TAG, "sleep(1000)...");

Thread.sleep(1000);

} catch (InterruptedException e) {

}

} while (isPause);

count ++;

}

};

}

if(mTimer != null && mTimerTask != null )

mTimer.schedule(mTimerTask, delay, period);

}

private void stopTimer(){

if (mTimer != null) {

mTimer.cancel();

mTimer = null;

}

if (mTimerTask != null) {

mTimerTask.cancel();

mTimerTask = null;

}

count = 0;

}

public void sendMessage(int id){

if (mHandler != null) {

Message message = Message.obtain(mHandler, id);

mHandler.sendMessage(message);

}

}

}

xml部分代码：

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:orientation="vertical" >

android:id="@+id/mytextview"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:gravity="center"

android:text="@string/number" />

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:gravity="center"

android:orientation="horizontal" >

android:id="@+id/mybutton_start"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="@string/start" />

android:id="@+id/mybutton_pause"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="@string/pause" />

string部分代码：

TimerDemo

0

start

stop

pause

resume

上面就是我的源代码，如果大家有什么问题可以留言进行探讨。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。