android studio秒表代码，包含开始、暂停

和重置功能的完整代码是什么？

以下是一个简单的 Android Studio 秒表代码，包含开始、暂停和重置功能的完整代码：

public class MainActivity extends AppCompatActivity {

    private TextView mTextView;
    private Button mStartButton, mPauseButton, mResetButton;
    private Handler mHandler = new Handler();
    private long mStartTime, mTimeInMillis, mTimeSwapBuff, mUpdateTime = 0L;

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

        mTextView = findViewById(R.id.textView);
        mStartButton = findViewById(R.id.startButton);
        mPauseButton = findViewById(R.id.pauseButton);
        mResetButton = findViewById(R.id.resetButton);

        mStartButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mStartTime = SystemClock.uptimeMillis();
                mHandler.postDelayed(mUpdateTimeTask, 0);
            }
        });

        mPauseButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mTimeSwapBuff += mTimeInMillis;
                mHandler.removeCallbacks(mUpdateTimeTask);
            }
        });

        mResetButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mTimeInMillis = 0L;
                mTimeSwapBuff = 0L;
                mUpdateTime = 0L;
                mTextView.setText("00:00:00");
            }
        });
    }

    private Runnable mUpdateTimeTask = new Runnable() {
        public void run() {
            mTimeInMillis = SystemClock.uptimeMillis() - mStartTime;
            mUpdateTime = mTimeSwapBuff + mTimeInMillis;
            int seconds = (int) (mUpdateTime / 1000);
            int minutes = seconds / 60;
            seconds = seconds % 60;
            int milliseconds = (int) (mUpdateTime % 1000);
            mTextView.setText("" + String.format("%02d", minutes) + ":" + String.format("%02d", seconds) + ":" + String.format("%03d", milliseconds));
            mHandler.postDelayed(this, 0);
        }
    };
}

这段代码使用了一个 Handler 对象来更新秒表的时间，同时使用了 SystemClock.uptimeMillis() 方法来获取当前时间。开始按钮会记录开始时间并启动一个更新任务，暂停按钮会记录当前时间并停止更新任务，重置按钮会将所有时间重置为零并清空文本视图。