24 小时时间选择器选择的时间 [英] 24 hours Time Picker selected time

问题描述

我尝试实施 24 小时 Time Picker 作为给定 此处 在 XF 项目中.

I tried implementing 24 Hour Time Picker as given here in XF project.

还有 Focus 和 Unfocused 事件的问题，之前已解决，请参阅 这里

Also their was an issue with the Focus and Unfocused events which was solved earlier, see here

现在我想设置 Time Picker 是 Focused 的时间，假设我已经将 2 小时绑定到 Time 属性，它应该选择了 2 小时打开，这不起作用.

Now I want to set the time when the Time Picker is Focused, say I have binded 2 hours to the Time property it should open with 2 hours selected, which is not working.

我注意到之前的时间被绑定在 Time Picker(被选中并点击 Ok 的时间)，但我想要 Time代码> 绑定到被选中.我正在使用 Xamarin Forms 2.5.0.121934.

I have noticed the previous time gets binded on the Time Picker(time which was selected and Ok was clicked), but I want the Time which is binded to be selected. I am using Xamarin Forms 2.5.0.121934.

我使用了 Constant.TimeToBeShowOnPicker.Hours 和 Constant.TimeToBeShowOnPicker.Minutes在绑定 Time else 的第一个值的代码中，默认情况下它是 0:00 hrs 或您设置的任何值.

I have used Constant.TimeToBeShowOnPicker.Hours and Constant.TimeToBeShowOnPicker.Minutes in the code to bind the first value of the Time else by default it is 0:00 hrs or whatever value you set.

public class TimePicker24Hours : ViewRenderer<Xamarin.Forms.TimePicker, Android.Widget.EditText>, TimePickerDialog.IOnTimeSetListener, IJavaObject, IDisposable
{
    private TimePickerDialog dialog = null;

    IElementController ElementController => Element as IElementController;

    protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.TimePicker> e)
    {
        base.OnElementChanged(e);
        this.SetNativeControl(new Android.Widget.EditText(Forms.Context));
        this.Control.Click += Control_Click;
        this.Control.Text = DateTime.Now.ToString("HH:mm");
        this.Control.KeyListener = null;
        this.Control.FocusChange += Control_FocusChange;
    }

    void Control_FocusChange(object sender, Android.Views.View.FocusChangeEventArgs e)
    {
        if (e.HasFocus)
        {
            ShowTimePicker();
            ElementController.SetValueFromRenderer(VisualElement.IsFocusedPropertyKey, true);
        }
        else
        {
            ElementController.SetValueFromRenderer(VisualElement.IsFocusedPropertyKey, false);
        }
    }

    void Control_Click(object sender, EventArgs e)
    {
        ShowTimePicker();
    }

    private void ShowTimePicker()
    {
        if (dialog == null)
        {
            dialog = new TimePickerDialog(Forms.Context, this, Constant.TimeToBeShowOnPicker.Hours, Constant.TimeToBeShowOnPicker.Minutes, true);
        }

        dialog.Show();
    }

    public void OnTimeSet(Android.Widget.TimePicker view, int hourOfDay, int minute)
    {
        var time = new TimeSpan(hourOfDay, minute, 0);
        this.Element.SetValue(Xamarin.Forms.TimePicker.TimeProperty, time);

        this.Control.Text = time.ToString(@"hh\:mm");

        this.ClearFocus();
    }
}

Xamarin.Forms XAML

<TimePicker x:Name="time_Picker" Time="{Binding SelectedTime}" IsVisible="false" PropertyChanged="TimePicker_PropertyChanged" />

当Time Picker被要求来到Focus

void EditTime_Tapped(object sender, System.EventArgs e)
{
    var eventArgs = e as TappedEventArgs;
    ViewModel.SelectedTaskItem = (SomeModel)eventArgs.Parameter;

    ViewModel.SelectedTime = TimeSpan.FromHours(ViewModel.SomeModel.Time);
    Constant.TimeToBeShowOnPicker = ViewModel.SelectedTime;

    Device.BeginInvokeOnMainThread(() =>
    {
        time_Picker.Focus();
    });
}

推荐答案

答案

为了确保当前时间在点击时显示在时间选择器上，我们需要在 ShowPicker() 中包含 UpdateTime.

我还注意到 Control.Text 总是默认为 DateTime.Now.要解决这个问题，我们只需要在 OnElementChanged 中设置 Control.Text.

I also noticed that Control.Text always defaults to DateTime.Now. To fix this, we just need to set Control.Text in OnElementChanged.

我已经更新了自定义渲染器以检查是否设置了 Element.Time，如果设置了，那么我们可以设置 Control.Text = Element.Time.ToString(@"hh\:mm");

I've updated the Custom Renderers to check if Element.Time is set, and if it is then we can set Control.Text = Element.Time.ToString(@"hh\:mm");

我在这里创建了一个示例 Xamarin.Forms 应用程序，它使用了这个 24 小时时间选择器:https://github.com/brminnick/24HourTimePicker

I've created a sample Xamarin.Forms app here that uses this 24 Hour Time Picker: https://github.com/brminnick/24HourTimePicker

using System;

using Foundation;

using TimePickerDemo;
using TimePickerDemo.iOS;

using UIKit;

using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;

[assembly: ExportRenderer(typeof(CustomTimePicker24H), typeof(CustomTimePicker24HRenderer))]
namespace TimePickerDemo.iOS
{
    public class CustomTimePicker24HRenderer : TimePickerRenderer
    {
        protected override void OnElementChanged(ElementChangedEventArgs<TimePicker> e)
        {
            base.OnElementChanged(e);

            if (Control != null)
            {
                var timePicker = (UIDatePicker)Control.InputView;
                timePicker.Locale = new NSLocale("no_nb");

                if (Element != null && !Element.Time.Equals(default(TimeSpan)))
                    Control.Text = Element.Time.ToString(@"hh\:mm");
                else
                    Control.Text = DateTime.Now.ToString("HH:mm");
            }
        }
    }
}

Android 自定义渲染器

using System;

using Android.App;
using Android.Text;
using Android.Content;
using Android.Runtime;

using Java.Lang;

using TimePickerDemo;
using TimePickerDemo.Droid;

using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;

[assembly: ExportRenderer(typeof(CustomTimePicker24H), typeof(CustomTimePicker24HRenderer))]
namespace TimePickerDemo.Droid
{
    public class CustomTimePicker24HRenderer : ViewRenderer<TimePicker, Android.Widget.EditText>, TimePickerDialog.IOnTimeSetListener, IJavaObject, IDisposable
    {
        TimePickerDialog _dialog;

        public CustomTimePicker24HRenderer(Context context) : base(context)
        {

        }

        Context CurrentContext => Plugin.CurrentActivity.CrossCurrentActivity.Current.Activity;
        IElementController ElementController => Element as IElementController;

        public void OnTimeSet(Android.Widget.TimePicker view, int hourOfDay, int minute)
        {
            var time = new TimeSpan(hourOfDay, minute, 0);
            Element.SetValue(TimePicker.TimeProperty, time);

            Control.Text = time.ToString(@"hh\:mm");

            ClearFocus();
        }

        protected override void OnElementChanged(ElementChangedEventArgs<TimePicker> e)
        {
            base.OnElementChanged(e);

            SetNativeControl(new Android.Widget.EditText(CurrentContext));

            if (Control != null)
            {
                Control.Click += Control_Click;
                Control.FocusChange += Control_FocusChange;

                if (Element != null && !Element.Time.Equals(default(TimeSpan)))
                    Control.Text = Element.Time.ToString(@"hh\:mm");
                else
                    Control.Text = DateTime.Now.ToString("HH:mm");
            }
        }

        void Control_FocusChange(object sender, FocusChangeEventArgs e)
        {
            if (e.HasFocus)
            {
                ShowTimePicker();
                ElementController.SetValueFromRenderer(VisualElement.IsFocusedPropertyKey, true);
            }
            else
            {
                ElementController.SetValueFromRenderer(VisualElement.IsFocusedPropertyKey, false);
            }
        }

        void Control_Click(object sender, EventArgs e) => ShowTimePicker();

        void ShowTimePicker()
        {
            if (_dialog == null)
                _dialog = new TimePickerDialog(CurrentContext, this, Element.Time.Hours, Element.Time.Minutes, true);

            _dialog.UpdateTime(Element.Time.Hours, Element.Time.Minutes);

            _dialog.Show();
        }
    }
}

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