Question

我想创建一个简单的计时器，当我点击button开始计时时，当我第二次点击按钮时，我会得到经过的时间（以毫秒为单位）到textView。

public class MainActivity extends AppCompatActivity {
int i = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    final TextView textView = (TextView) findViewById(R.id.textView);
    Button button = (Button) findViewById(R.id.button);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            long start = System.currentTimeMillis();
            i++;
            if (i >= 2)
            {
                long end = System.currentTimeMillis();
                long diff = end - start;
                textView.setText(String.valueOf(diff));
            }
        }
    });

}

启动应用
时，我的值为0

Answer 1

public class MainActivity extends AppCompatActivity {
private long start = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    final TextView textView = (TextView) findViewById(R.id.textView);
    Button button = (Button) findViewById(R.id.button);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (start > 0) {
                long end = System.currentTimeMillis();
                long diff = end - start;
                textView.setText(String.valueOf(diff));
                start = 0;
            } else {
                start = System.currentTimeMillis();
            }
    });

}

Answer 2

每次点击按钮都会保存start，因此start和end应该几乎相同。

final TextView textView = (TextView) findViewById(R.id.textView);
Button button = (Button) findViewById(R.id.button);
long start = -1;
button.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        if(start < 0)
            start = System.currentTimeMillis();
        else {
            long end = System.currentTimeMillis();
            long diff = end - start;
            textView.setText(String.valueOf(diff));
            start = -1;
        }
    }
});

Answer 3

试试这个

   int i = 1;
   long start,end;

    Button button = (Button) findViewById(R.id.button);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (i == 2)
            {
                end = System.currentTimeMillis();
                long diff = end - start;
                textView.setText(String.valueOf(diff));
                i = 1;
            }
            else
            {
                start = System.currentTimeMillis();
                i++;
            }
        }
    });

如何衡量点击之间的时间？

3 个答案: