问题描述
我需要在时间选择器中设置15分钟间隔。我已经为iOS做过。但是在Android中，它不起作用。
对于iOS，我使用了以下代码，并且可以正常工作：
public class CustomTimePickerRenderer : TimePickerRenderer
{
protected override void OnElementChanged(ElementChangedEventArgs<TimePicker> e)
{
base.OnElementChanged(e);
var view = (TimePicker)Element;
if (view != null)
{
var timePicker = (UIDatePicker)Control.InputView;
timePicker.MinuteInterval = 15;
}
}
}
对于Andoroid，我正在尝试以下代码：
public class CustomTimePickerRenderer : TimePickerRenderer
{
Context _context;
public CustomTimePickerRenderer(Context context) : base(context)
{
_context = context;
}
protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.TimePicker> e)
{
base.OnElementChanged(e);
TimePickerDialogIntervals timePickerDlg = new TimePickerDialogIntervals(this.Context,new EventHandler<TimePickerDialogIntervals.TimeSetEventArgs>(UpdateDuration),Element.Time.Hours,Element.Time.Minutes,true);
var control = new EditText(this.Context);
control.Focusable = false;
control.FocusableInTouchMode = false;
control.Clickable = false;
control.Click += (sender,ea) => timePickerDlg.Show();
control.Text = Element.Time.Hours.ToString("00") + ":" + Element.Time.Minutes.ToString("00");
SetNativeControl(control);
}
void UpdateDuration(object sender,Android.App.TimePickerDialog.TimeSetEventArgs e)
{
Element.Time = new TimeSpan(e.HourOfDay,e.Minute,0);
Control.Text = Element.Time.Hours.ToString("00") + ":" + Element.Time.Minutes.ToString("00");
}
}
public class TimePickerDialogIntervals : TimePickerDialog
{
public const int TimePickerInterval = 15;
private bool _ignoreEvent = false;
public TimePickerDialogIntervals(Context context,EventHandler<TimePickerDialog.TimeSetEventArgs> callBack,int hourOfDay,int minute,bool is24HourView)
: base(context,(sender,e) => {
callBack(sender,new TimePickerDialog.TimeSetEventArgs(e.HourOfDay,e.Minute * TimePickerInterval));
},hourOfDay,minute / TimePickerInterval,is24HourView)
{
}
protected TimePickerDialogIntervals(IntPtr javaReference,JniHandleOwnership transfer) : base(javaReference,transfer)
{
}
public override void SetView(Android.Views.View view)
{
SetupMinutePicker(view);
base.SetView(view);
}
void SetupMinutePicker(Android.Views.View view)
{
var numberPicker = FindMinuteNumberPicker(view as ViewGroup);
if (numberPicker != null)
{
numberPicker.MinValue = 0;
numberPicker.MaxValue = 3;
numberPicker.SetdisplayedValues(new String[] { "00","15","30","45" });
}
}
protected override void OnCreate(Android.OS.Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
GetButton((int)DialogButtonType.Negative).Visibility = Android.Views.ViewStates.Gone;
this.SetCanceledOnTouchOutside(false);
}
private NumberPicker FindMinuteNumberPicker(ViewGroup viewGroup)
{
for (var i = 0; i < viewGroup.ChildCount; i++)
{
var child = viewGroup.GetChildAt(i);
var numberPicker = child as NumberPicker;
if (numberPicker != null)
{
if (numberPicker.MaxValue == 59)
{
return numberPicker;
}
}
var childViewGroup = child as ViewGroup;
if (childViewGroup != null)
{
var childResult = FindMinuteNumberPicker(childViewGroup);
if (childResult != null)
return childResult;
}
}
return null;
}
}
但是Android代码无法正常工作。我认为问题出在SetupMinutePicker方法中的数字选择器上。我在数字选择器中得到了空值。 请让我知道如何解决此数字选择器问题，或者是否有其他替代方法来设置15分钟的时间选择器。
解决方法
我找到了适用于Android的解决方法。先前的覆盖INSERT INTO My_Table (COMMON_ID,COMMON_LIMIT_IDENTITY,COMMON_CLASS_ID,COMMON_ASSET_TYPE)
SELECT NEWID(),'USER'
FROM My_Table
WHERE COMMON_ASSET_TYPE = 'ASSET'
方法现在无法获取SetView(...)，在这里我们可以按如下方式更改覆盖NumberPicker方法中的分钟间隔：
OnTimeChanged完整的android渲染器代码如下：
public override void OnTimeChanged(Android.Widget.TimePicker view,int hourOfDay,int minute)
{
if (_ignoreEvent) return;
if (minute % TimePickerInterval != 0)
{
int minuteFloor = minute - (minute % TimePickerInterval);
minute = minuteFloor + (minute == minuteFloor + 1 ? TimePickerInterval : 0);
if (minute == 60)
minute = 0;
_ignoreEvent = true;
view.CurrentMinute = (Java.Lang.Integer)minute;
_ignoreEvent = false;
}
}
效果：
对我来说，Junior Jiang 的解决方案在 Xamarin.Forms 5.0 中不再适用。这样做的原因是基础渲染器总是调用自己的 TimePickerDialog。幸运的是，您可以覆盖必要的方法。
我还改变了分钟跳转到最接近当前位置的下一个间隔的行为。我认为这比完全拉到下一个间隔要快得多。分钟的某些特定值也有轻微的计算错误，导致指针闪烁。
public class IntervalTimePickerRenderer : TimePickerRenderer
{
private Context _context;
public IntervalTimePickerRenderer(Context context) : base(context)
{
_context = context;
}
protected override TimePickerDialog CreateTimePickerDialog(int hours,int minutes)
{
return new TimePickerDialogIntervals(
Context,UpdateDuration,hours,minutes,DateFormat.Is24HourFormat(_context));
}
void UpdateDuration(object sender,TimePickerDialog.TimeSetEventArgs e)
{
Element.Time = new TimeSpan(e.HourOfDay,e.Minute,0);
Control.Text = Element.Time.Hours.ToString("00") + ":" + Element.Time.Minutes.ToString("00");
Element.Unfocus();
}
}
public class TimePickerDialogIntervals : TimePickerDialog
{
public const int TimePickerInterval = 15;
private bool _ignoreEvent = false;
public TimePickerDialogIntervals(
Context context,EventHandler<TimeSetEventArgs> callBack,int minute,bool is24HourView)
: base(context,(sender,e) =>
{
callBack(sender,new TimePickerDialog.TimeSetEventArgs(e.HourOfDay,e.Minute));
},hourOfDay,minute,is24HourView)
{
}
public override void OnTimeChanged(Android.Widget.TimePicker view,int minute)
{
base.OnTimeChanged(view,minute);
if (_ignoreEvent) return;
if (minute % TimePickerInterval != 0)
{
float minuteFactor = (float)minute / TimePickerInterval;
int intervalFactor = (int)Math.Round(minuteFactor,0);
minute = intervalFactor * TimePickerInterval;
if (minute == 60)
{
minute = 0;
}
_ignoreEvent = true;
view.Minute = minute;
_ignoreEvent = false;
}
}
}