Question

我的问题是在底部，我有一个布尔值， 正在进行 ，这是假的。按下按钮应该成为真，然后启动倒数计时器，但不启动计时器。计时器工作在代码中的其他位置。对不起，如果它是一个完全混乱我不熟悉。

public int counter;
public boolean ongoing = false;

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

    //0-59 number picker to represent seconds
    final NumberPicker secPicker = (NumberPicker) findViewById(R.id.secPicker);
    secPicker.setMaxValue(59);


    Button btnStart = (Button) findViewById(R.id.btnStart);
    Button btnSet = (Button) findViewById(R.id.btnSet);
    Button btnPause = (Button) findViewById(R.id.btnPause);
    final TextView label = (TextView) findViewById(R.id.txtCount);


    //sets the time chosen to timer with button press btnSet
    btnSet.setOnClickListener(
            new View.OnClickListener() {
                public void onClick(View v) {
                    counter = secPicker.getValue();
                    label.setText(String.valueOf(counter));
                }
            }
    );


    //starts timer from selected time, from number picker, with btnStart
    btnStart.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            ongoing = true;


        }
    });
    //disables, not worried about this yet
    btnPause.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            ongoing = false;


        }
    });


        //supposed to turn on a timer with button press btnStart, but it does nothing this is my problem.
        if (ongoing == true) {
            //any replacement for 9999999, as an infinite value?
            new CountDownTimer(999999999, 1000) {
                public void onTick(long millisUntilFinished) {
                    label.setText(String.valueOf(counter));
                    counter--;
                    if (counter == -1) {
                        counter = 0;
                        cancel();
                    }
                }

                public void onFinish() {

                }

            }.start();

        }
    }
}

Answer 1

 if (ongoing == true) // this will never work for you

在点击任何可以调用的内容之前，你已经将上面的代码放在了oncreate中。

要么在btnStart点击事件中写下面的代码，要么创建一个方法并从中调用。

//应该按下按钮按btnStart打开一个计时器，但它没有做任何事这是我的问题。

if (ongoing == true) {
    //any replacement for 9999999, as an infinite value?
    new CountDownTimer(999999999, 1000) {
        public void onTick(long millisUntilFinished) {
            label.setText(String.valueOf(counter));
            counter--;
            if (counter == -1) {
                counter = 0;
                cancel();
            }
        }

        public void onFinish() {

        }

    }.start();

}

希望这些可以帮助你。

CountDownTimer不在if语句中启动

1 个答案: