安卓开发——计时器

效果图

 

 

 

xml样式文件

<Button
    android:id="@+id/btnOk"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="开始计时"
    android:textSize="15dp" />

<TextView
    android:id="@+id/tvTime"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textSize="15dp" />

java功能文件，修改类名

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private Button btnOk;
    private TextView tvTime;

    private boolean bStart=false;
    private Handler mHander=new Handler();
    private int mCount=0;

    private Runnable mCounter=new Runnable() {
        @Override
        public void run() {
            mCount++;
            tvTime.setText("当前计数值:"+mCount);
            mHander.postDelayed(this,1000);
        }
    };

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

    private void initView() {
        btnOk = (Button) findViewById(R.id.btnOk);
        tvTime = (TextView) findViewById(R.id.tvTime);

        btnOk.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btnOk:
                if (bStart==false){
                    btnOk.setText("停止计时");
                    mHander.post(mCounter);
                }else{
                    btnOk.setText("开始计时");
                    mHander.removeCallbacks(mCounter);
                }
                bStart=!bStart;
                break;
        }
    }
}