简单的倒计时程序—CountTime

Timer 和 TimerTask 实现

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.gavin.counttime.MainActivity">
    <EditText
        android:id="@+id/InputTime"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:ems="10"/>
    <Button
        android:id="@+id/GetTime"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/Get_Time"/>
    <TextView
        android:id="@+id/Time"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
    <Button
        android:id="@+id/Begin"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/Begin"/>
    <Button
        android:id="@+id/Stop"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/Stop"/>

</LinearLayout>

<resources>
    <string name="app_name">CountTime</string>
    <string name="Get_Time">获取倒计时时间</string>
    <string name="Begin">开始计时</string>
    <string name="Stop">停止计时</string>
</resources>

import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

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


public class MainActivity extends AppCompatActivity implements View.OnClickListener{

    private EditText mInputText;
    private Button mGetTime,mStartTime,mStopTime;
    private TextView mtime;
    private int mSecond;
    private Timer mTimer = null;
    private TimerTask mTimerTask = null; //两个timer必须配合使用
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        initView();

    }

    private void initView(){
        mInputText = (EditText)findViewById(R.id.InputTime);
        mGetTime = (Button)findViewById(R.id.GetTime);
        mStartTime = (Button)findViewById(R.id.Begin);
        mStopTime = (Button)findViewById(R.id.Stop);
        mtime = (TextView)findViewById(R.id.Time);

        mGetTime.setOnClickListener(this);
        mStartTime.setOnClickListener(this);
        mStopTime.setOnClickListener(this);
    }



    @Override
    public void onClick(View v){
        switch (v.getId()) {
            case R.id.GetTime:
                mtime.setText(mInputText.getText().toString());
                mSecond = Integer.parseInt(mInputText.getText().toString());
                break;
            case R.id.Begin:
                StartTime();
                break;
            case R.id.Stop:
                StopTime();
                break;
        }
    }

    private Handler mHandler = new Handler() {
        public void handleMessage(Message msg) {
            mtime.setText(msg.arg1+" ");
            StartTime();
            if(msg.arg1 == 0) {
                mtime.setText("计时结束");
                StopTime();
            }
        };
    };

    public void StartTime() {
        mTimer = new Timer();
        mTimerTask = new TimerTask() {
            @Override
            public void run() {
                mSecond--;
                Message message = mHandler.obtainMessage();
                message.arg1 = mSecond;
                mHandler.sendMessage(message);
            }
        };
        mTimer.schedule(mTimerTask,1000);
    }

    public void StopTime() {
        mTimer.cancel();
    }

}