防止用户选择过去的时间 - TimePickerDialog

Question

重要编辑：我做了一些搜索，似乎 OnTimeChangedListener 在 Android 5.0 (API 21) 中没有触发。 Gustavo 下面的答案适用于 API 20 或更低版本，以及我测试过的 API 22。 (Source)

我想阻止用户输入当前时间之前的时间。我使用Date 提供的before 方法检查有效时间。如何防止对话框在此有效性检查中接受无效时间？

我省略了初始化所选时间的多余代码（作为Date）。

final Calendar mcurrentTime = Calendar.getInstance();
final int hour = mcurrentTime.get(Calendar.HOUR_OF_DAY);
final int minute = mcurrentTime.get(Calendar.MINUTE);
final TimePickerDialog mTimePicker;
mTimePicker = new TimePickerDialog(MainActivity.this, new TimePickerDialog.OnTimeSetListener() {
    @Override
    public void onTimeSet(TimePicker timePicker, int selectedHour, int selectedMinute) {

        //PSEUDO: Date selectedDateTime init here

        if (selectedDateTime.before(mcurrentTime.getTime())) {
            // prevent user from selecting time
        }
    }
}, hour, minute, true);//true = 24 hour time
mTimePicker.setTitle("Select Time");
mTimePicker.show(); 

Answer 1

Here原帖。

按照答案，您应该添加 TimePickerDialog 类。

public class RangeTimePickerDialog extends TimePickerDialog {

private int minHour = -1;
private int minMinute = -1;

private int maxHour = 25;
private int maxMinute = 25;

private int currentHour = 0;
private int currentMinute = 0;

private Calendar calendar = Calendar.getInstance();
private DateFormat dateFormat;


public RangeTimePickerDialog(Context context, OnTimeSetListener callBack, int hourOfDay, int minute, boolean is24HourView) {
    super(context, callBack, hourOfDay, minute, is24HourView);
    currentHour = hourOfDay;
    currentMinute = minute;
    dateFormat = DateFormat.getTimeInstance(DateFormat.SHORT);

    try {
        Class<?> superclass = getClass().getSuperclass();
        Field mTimePickerField = superclass.getDeclaredField("mTimePicker");
        mTimePickerField.setAccessible(true);
        TimePicker mTimePicker = (TimePicker) mTimePickerField.get(this);
        mTimePicker.setOnTimeChangedListener(this);
    } catch (NoSuchFieldException e) {
    } catch (IllegalArgumentException e) {
    } catch (IllegalAccessException e) {
    }
}

public void setMin(int hour, int minute) {
    minHour = hour;
    minMinute = minute;
}

public void setMax(int hour, int minute) {
    maxHour = hour;
    maxMinute = minute;
}

@Override
public void onTimeChanged(TimePicker view, int hourOfDay, int minute) {

    Log.d("DADADADA", "onTimeChanged");

    boolean validTime = true;
    if (hourOfDay < minHour || (hourOfDay == minHour && minute < minMinute)) {
        validTime = false;
    }

    if (hourOfDay > maxHour || (hourOfDay == maxHour && minute > maxMinute)) {
        validTime = false;
    }

    if (validTime) {
        currentHour = hourOfDay;
        currentMinute = minute;
    }

    updateTime(currentHour, currentMinute);
    updateDialogTitle(view, currentHour, currentMinute);
}

private void updateDialogTitle(TimePicker timePicker, int hourOfDay, int minute) {
    calendar.set(Calendar.HOUR_OF_DAY, hourOfDay);
    calendar.set(Calendar.MINUTE, minute);
    String title = dateFormat.format(calendar.getTime());
    setTitle(title);
}
}

之后，将 TimePickerDialog 替换为 RangeTimePickerDialog

public class MainActivity extends Activity {

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

    final Calendar mcurrentTime = Calendar.getInstance();
    final int hour = mcurrentTime.get(Calendar.HOUR_OF_DAY);
    final int minute = mcurrentTime.get(Calendar.MINUTE);
    final RangeTimePickerDialog mTimePicker;
    mTimePicker = new RangeTimePickerDialog(MainActivity.this, new TimePickerDialog.OnTimeSetListener() {
        @Override
        public void onTimeSet(TimePicker timePicker, int selectedHour, int selectedMinute) {

            Log.d("TAG", "inside OnTimeSetListener");

        }
    }, hour, minute, true);//true = 24 hour time
    mTimePicker.setTitle("Select Time");
    mTimePicker.setMin(hour, minute);
    mTimePicker.show();
}
}

在那之后，检查你的对话框，时间没有超过限制，我已经用 setMax() 或 setMin() 进行了检查，并且只设置了一个。

Answer 2

方法onTimeSet() 在对话框关闭时调用一次，在单击完成按钮时调用两次。

我会在第二次调用时在该方法中验证。忽略第一个。如果无效，则显示错误（可能是 toast）并再次显示对话框

细化

两个onTimeSet 调用将是相同的时间。现在，我没有参考，但我相信 one 调用是在显示对话框时（时间设置与否）然后被取消。 二 就是这样，但不是取消，而是当用户点击“完成”时。

我说忽略第一个的原因是可以设置时间，并决定取消。在这种情况下，不要接受onTimeSet()。如果这对您来说无关紧要，则无需担心。