Android 開發第一彈：倒計時

好吧……我承認很尴尬……

但畢竟作為開端，還是將這個貼出來，以後一定寫出厲害的！

package myapplication.nomasp.com.timer;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
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 Activity implements View.OnClickListener {

    private EditText etInputNum,etOutputNum;
    private Button btnGetNum,btnStartCount,btnStopCount;
    private TextView tvOutputNum;
    private  int i=0;
    private Timer timer=null;
    private TimerTask task=null;

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

    private void initView(){
        etInputNum=(EditText)findViewById(R.id.etInputNum);
        btnGetNum=(Button)findViewById(R.id.btnGetNum);
        btnStartCount=(Button)findViewById(R.id.btnStartCount);
        btnStopCount=(Button)findViewById(R.id.btnStopCount);
        tvOutputNum=(TextView)findViewById(R.id.tvOutputNum);
        btnGetNum.setOnClickListener(this);
        btnStartCount.setOnClickListener(this);
        btnStopCount.setOnClickListener(this);
    }

    @Override
    public void onClick(View v)
    {
        switch (v.getId())
        {
            case R.id.btnGetNum:
                tvOutputNum.setText(etInputNum.getText().toString());
                i=Integer.parseInt(etInputNum.getText().toString());
                break;
            case R.id.btnStartCount:
                startTime();
                break;
            case R.id.btnStopCount:
                stopTime();
                break;
            default:
                break;
        }
    }

    private Handler mHandler=new Handler(){
        public void handleMessage(Message msg){
            tvOutputNum.setText(msg.arg1+);
            startTime();
        };
    };

    public void startTime(){
        timer=new Timer();
        task =new TimerTask() {
            @Override
            public void run() {
                i--;
                Message message=mHandler.obtainMessage();
                message.arg1=i;
                mHandler.sendMessage(message);
            }
        };
        timer.schedule(task,1000);
    }

    public void stopTime(){
        timer.cancel();
    }
}

加油！