如何制作带有点的自定义文本视图?

how do I make a custom textview that has dots?

我正在尝试制作一个日历,我想向用户显示有关特定日期存储的事件的某种信息。我正在考虑使用带有他们为活动选择的颜色的小点,但我似乎无法找到一种方法来做到这一点,如果可能的话...... 我有这个: 我想要这样的东西:

有人可以帮助我,或者给我一些建议吗?

您可以尝试使用第三方库 material-calendarview to implement this feature, it provide a DayViewDecorators class 来自定义个别日期:

  • 设置自定义背景
  • 设置自定义选择器
  • 将跨度应用于全天的文本
    • 我们提供 DotSpan 将在文本下方居中绘制一个点
  • 将日期设置为禁用

由于您正在使用 Xamarin.Android,因此您可以通过 Binding a Java Library.

在您的 Xamarin.Android 项目中使用此 java 库

顺便说一下,有人为您完成了这项工作:https://github.com/NAXAM/materialcalendarview-xamarin-android-binding, you could directly install it in nuget package。

用法简单

XAML中使用:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <com.prolificinteractive.materialcalendarview.MaterialCalendarView
        android:id="@+id/calendar_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginRight="16dp"
        android:background="@drawable/bg_custom_date_picker"
        app:mcv_selectionColor="@color/colorAccent"
        app:mcv_showOtherDates="other_months"
        android:layout_marginBottom="16dp"/>
</LinearLayout>

在您的代码中:

public class CalendarActivity : AppCompatActivity
{
    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        SetContentView(Resource.Layout.activity_calendar);

        MaterialCalendarView calendar = FindViewById<MaterialCalendarView>(Resource.Id.calendar_view);
        calendar.SetSelectedDate(Java.Util.Calendar.GetInstance(Java.Util.Locale.English));

        List<CalendarDay> dates = new List<CalendarDay>();

        CalendarDay a = CalendarDay.From(2018, 11, 10);
        CalendarDay b = CalendarDay.From(2018, 11, 15);
        CalendarDay c = CalendarDay.From(2018, 11, 9);
        CalendarDay d = CalendarDay.From(2018, 11, 1);

        dates.Add(a);
        dates.Add(b);
        dates.Add(c);
        dates.Add(d);

        calendar.AddDecorators(new EventDecorator(this, Color.Red, dates));
    }

    class EventDecorator : Java.Lang.Object, IDayViewDecorator
    {
        private int color;
        private List<CalendarDay> dates;

        public EventDecorator(CalendarActivity calendarActivity, int color, List<CalendarDay> dates)
        {
            this.color = color;
            this.dates = dates;
        }

        public void Decorate(DayViewFacade view)
        {
            view.AddSpan(new DotSpan(15, color));
        }

        public bool ShouldDecorate(CalendarDay day)
        {  
            //return dates.Contains(day);   
            //Has issue when using the above code: 

            if (dates[0].ToString() == day.ToString() || dates[1].ToString() == day.ToString() || dates[2].ToString() == day.ToString() || dates[3].ToString() == day.ToString())
            {
                return true;
            }
            else
            {
                return false;
            }
        }
    }
}

Effect.