android倒计时程序的崩溃问题

必须在分钟和秒两栏中都输入才可以正常计时，否则会崩溃，这是为什么？？求大侠帮忙！！！

Java代码是

```package com.example.countt;

import java.util.Timer;
import java.util.TimerTask;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity implements OnClickListener {
private EditText etMinute, etSecond;
private Button btnStartTime, btnStopTime;
private TextView time;
private int i = 0;
private int i2 = 0;
private Timer timer = null;
private TimerTask task = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    initViews();

}

private void initViews() {
    etMinute = (EditText) findViewById(R.id.etMinute);
    etSecond = (EditText) findViewById(R.id.etSecond);
    btnStartTime = (Button) findViewById(R.id.btnStartTime);
    btnStopTime = (Button) findViewById(R.id.stopTime);
    time = (TextView) findViewById(R.id.time);
    btnStartTime.setOnClickListener(this);
    btnStopTime.setOnClickListener(this);
}

@Override
public void onClick(View v) {

    switch (v.getId()) {
    case R.id.btnStartTime:
        i = Integer.parseInt(etSecond.getText().toString());
        i2 = Integer.parseInt(etMinute.getText().toString());
        startTime();
        break;
    case R.id.stopTime:
        stoptTime();
        break;

    default:
        break;
    }
}

private Handler sHandler = new Handler() {

    public void handleMessage(Message msg) {
        if (msg.arg1 == -1) {
            timer.cancel();
        } 
        else if(msg.arg1==0){
            time.setText("00:00");
        }
        else if (msg.arg1 != 0 && ((int) msg.arg1/60) < 10 && msg.arg1%60 < 10) {
            time.setText("0" + (int) msg.arg1 / 60 + ":" + "0" + msg.arg1
                    % 60);
            startTime();
        } else if (msg.arg1 != 0 && ((int) msg.arg1/60) > 10 && msg.arg1%60 < 10) {
            time.setText((int) msg.arg1 / 60 + ":" + "0" + msg.arg1 % 60);
            startTime();
        } else if (msg.arg1 != 0 && ((int) msg.arg1/60) < 10 && msg.arg1%60 > 10) {
            time.setText("0" + (int) msg.arg1 / 60 + ":" + msg.arg1 % 60);
            startTime();
        } else {
            time.setText((int) msg.arg1 / 60 + ":" + msg.arg1 % 60);
            startTime();
        }
    };

};

private void startTime() {
    timer = new Timer();
    task = new TimerTask() {

        @Override
        public void run() {
            if(i==0&&i2==0){
                timer.cancel();
            }
            if(i2==0&&i!=0){
                Message msg = sHandler.obtainMessage();
                msg.arg1 = i;
                sHandler.sendMessage(msg);
            }
            else if (i == 0&&i2!=0) {
                i2--;
                i = 60;
                Message msg = sHandler.obtainMessage();
                msg.arg1 = i + i2 * 60;
                sHandler.sendMessage(msg);
            } else {
                i--;
                Message msg = sHandler.obtainMessage();
                msg.arg1 = i + i2 * 60;
                sHandler.sendMessage(msg);
            }
        }
    };
    timer.schedule(task, 1000);

}

private void stoptTime() {
    timer.cancel();
}

}


layout布局文件是


```<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:orientation="vertical"
    tools:context="com.example.countt.MainActivity" >
<LinearLayout android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal">


    <EditText
        android:id="@+id/etMinute"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        >
    </EditText>
    <TextView android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="分钟  "/>

    <EditText
        android:id="@+id/etSecond"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
          >
    </EditText>
    <TextView android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="秒  "/>


</LinearLayout>

<LinearLayout android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center"
    android:orientation="horizontal">

    <TextView
        android:gravity="center"
        android:id="@+id/time"
        android:layout_width="match_parent"
        android:layout_height="300dp"
        android:text="00:00"
        android:textColor="#0000ff"
        android:textSize="40sp" />
    </LinearLayout>

    <Button
        android:id="@+id/btnStartTime"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="开始计时" />

    <Button
        android:id="@+id/stopTime"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="停止计时" />

</LinearLayout>

图

图片说明

1。安卓有这个控件 Chronometer，你最好用这个；自己做，肯定要用到线程；
2.我估计你是线程崩溃，引起的崩溃；

不嫌弃的话可以试试我这个，不过没什么注释

public class CustomTimer {
private Handler mHandler;
private static final int TIME_UNIT = 1000;
private static final int RADIX = 60;
private int totalSec = 0;
private Timer mTimer;
private TimerTask mTask;

public static final int MSG_WHAT = 1111;
public static final int MSG_PAUSE = 1112;
public static final int MSG_CONTINUE = 1113;

public CustomTimer(final Handler handler) {
    this.mHandler = handler;
    mTimer = new Timer(true);
}

/**
 * 倒计时秒数
 *
 * @param max
 */
public void countDownTime(final int max) {
    if (mTimer == null)
        mTimer = new Timer(true);

    mTask = new TimerTask() {
        @Override
        public void run() {
            Message mMessage = mHandler.obtainMessage();
            mMessage.what = MSG_WHAT;
            totalSec++;
            mMessage.obj = max - totalSec;
            mHandler.sendMessage(mMessage);
        }
    };
    mTimer.schedule(mTask, TIME_UNIT, TIME_UNIT);

}

/**
 * 倒计时时分秒
 *
 * @param max
 */
public void countDownFormatTime(final int max) {
    if (mTimer == null)
        mTimer = new Timer(true);

    mTask = new TimerTask() {
        @Override
        public void run() {
            Message mMessage = mHandler.obtainMessage();
            mMessage.what = MSG_WHAT;
            totalSec++;
            mMessage.obj = getFormatTime(max - totalSec);
            mHandler.sendMessage(mMessage);
        }
    };
    mTimer.schedule(mTask, TIME_UNIT, TIME_UNIT);

}


public void countTime(int start) {
    if (mTimer == null)
        mTimer = new Timer(true);
    totalSec = start;
    mTask = new TimerTask() {
        @Override
        public void run() {
            totalSec++;
            Message mMessage = mHandler.obtainMessage();
            mMessage.what = MSG_WHAT;
            mMessage.obj = getFormatTime(totalSec);
            mHandler.sendMessage(mMessage);
        }
    };
    mTimer.schedule(mTask, TIME_UNIT, TIME_UNIT);
}

public int stopCountDown() {
    int usedTime = totalSec;
    if (mTask != null) {
        mTask.cancel();
        totalSec = 0;
        mTask = null;
        mTimer = null;
    }
    return usedTime;
}

public String stopCountDownFormatTime() {
    String usedTime = getFormatTime(totalSec);
    if (mTask != null) {
        mTask.cancel();
        totalSec = 0;
        mTask = null;
        mTimer = null;
    }
    return usedTime;
}

public String stopCount() {
    String usedTime = getFormatTime(totalSec);
    if (mTask != null) {
        mTask.cancel();
        mTask = null;
        mTimer = null;
        totalSec = 0;
    }
    return usedTime;
}

public static String getFormatTime(int totalSec) {
    int minute = totalSec / RADIX;
    int second = totalSec % RADIX;
    return String.format("%1$02d:%2$02d", minute, second);
}

public static int getNotFormatTime(String time) {
    int ret = 0;
    if (time != null) {
        String[] split = time.split(":");
        ret = Integer.valueOf(split[0]) * 60 + Integer.valueOf(split[1]);
    }
    return ret;
}

}

这是一个简单的倒计时例子
mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch (msg.what) {
case CustomTimer.MSG_WHAT: //计时器发来的信息
String time = msg.obj.toString();
txt_time.setText(time); //计时操作
//考试时间到
if (time.equals("00:00")) {
txt_time.setText("00:00");
mTimer.stopCount();//停止计时操作

                    }
                    break;
            }
        }
    };

    mTimer = new CustomTimer(mHandler);//初始化计时器
            mTimer.countDownFormatTime(100);

            另外，还有正计时的功能。

public static final int MSG_WHAT = 1111;
public static final int MSG_PAUSE = 1112;
public static final int MSG_CONTINUE = 1113;

public CustomTimer(final Handler handler) {
this.mHandler = handler;
mTimer = new Timer(true);
}

/**

倒计时秒数 *
@param max
*/
public void countDownTime(final int max) {
if (mTimer == null)
mTimer = new Timer(true);
mTask = new TimerTask() {
@Override
public void run() {
Message mMessage = mHandler.obtainMessage();
mMessage.what = MSG_WHAT;
totalSec++;
mMessage.obj = max - totalSec;
mHandler.sendMessage(mMessage);
}
};
mTimer.schedule(mTask, TIME_UNIT, TIME_UNIT);

}

/**

倒计时时分秒 *
@param max
*/
public void countDownFormatTime(final int max) {
if (mTimer == null)
mTimer = new Timer(true);
mTask = new TimerTask() {
@Override
public void run() {
Message mMessage = mHandler.obtainMessage();
mMessage.what = MSG_WHAT;
totalSec++;
mMessage.obj = getFormatTime(max - totalSec);
mHandler.sendMessage(mMessage);
}
};
mTimer.schedule(mTask, TIME_UNIT, TIME_UNIT);

}

public void countTime(int start) {
if (mTimer == null)
mTimer = new Timer(true);
totalSec = start;
mTask = new TimerTask() {
@Override
public void run() {
totalSec++;
Message mMessage = mHandler.obtainMessage();
mMessage.what = MSG_WHAT;
mMessage.obj = getFormatTime(totalSec);
mHandler.sendMessage(mMessage);
}
};
mTimer.schedule(mTask, TIME_UNIT, TIME_UNIT);
}

public int stopCountDown() {
int usedTime = totalSec;
if (mTask != null) {
mTask.cancel();
totalSec = 0;
mTask = null;
mTimer = null;
}
return usedTime;
}

public String stopCountDownFormatTime() {
String usedTime = getFormatTime(totalSec);
if (mTask != null) {
mTask.cancel();
totalSec = 0;
mTask = null;
mTimer = null;
}
return usedTime;
}

public String stopCount() {
String usedTime = getFormatTime(totalSec);
if (mTask != null) {
mTask.cancel();
mTask = null;
mTimer = null;
totalSec = 0;
}
return usedTime;
}

public static String getFormatTime(int totalSec) {
int minute = totalSec / RADIX;
int second = totalSec % RADIX;
return String.format("%1$02d:%2$02d", minute, second);
}

public static int getNotFormatTime(String time) {
int ret = 0;
if (time != null) {
String[] split = time.split(":");
ret = Integer.valueOf(split[0]) * 60 + Integer.valueOf(split[1]);
}
return ret;
}

}

                }
                break;
        }
    }
};

mTimer = new CustomTimer(mHandler);//初始化计时器
        mTimer.countDownFormatTime(100);

        另外，还有正计时的功能。

你可以给时分都设置一个默认值呀