MaterialDatePicker显示当前日期，而不是需要的日期 [英] MaterialDatePicker shows current date instead of needed

问题描述

使用 MaterialDatePicker 我想显示所需的日期并有机会选择另一个.但是，当出现DatePicker时，它将显示当前日期，而不是指定的日期.

Using MaterialDatePicker I want to show required date and give an opportunity to select another. But when a DatePicker appears it shows current date instead of specified.

我插入了库:implementation 'com.google.android.material:material:1.2.0-alpha06'(或1.1.0).

I plug the library: implementation 'com.google.android.material:material:1.2.0-alpha06' (or 1.1.0).

然后在styles.xml中覆盖AppTheme:

<style name="AppTheme" parent="Theme.MaterialComponents.Light">

现在可以显示DatePicker.

And now can show DatePicker.

val now = Calendar.getInstance()
now[Calendar.YEAR] = 2020
now[Calendar.MONTH] = 10
now[Calendar.DAY_OF_MONTH] = 1
val builder = MaterialDatePicker.Builder.datePicker()
builder.setSelection(now.timeInMillis)

val picker = builder.build()
fragmentManager?.let { picker.show(it, MaterialDatePicker::class.java.simpleName) }

这是结果.我想显示11月1日，但是显示5月7日.

This is a result. I want to show 1st November, but it shows 7th May.

更新1

如上面链接中所述，我们可以使用CalendarConstraints.Builder:

As written in above link, we can use CalendarConstraints.Builder:

...
val constraintsBuilder = CalendarConstraints.Builder()
constraintsBuilder.setStart(now.timeInMillis)
constraintsBuilder.setEnd(now.timeInMillis)

val builder = MaterialDatePicker.Builder.datePicker()
builder.setCalendarConstraints(constraintsBuilder.build())
builder.setSelection(now.timeInMillis)
...

这将显示所需的日期，我们可以选择另一天，但不能滚动月份.

This will show required date, we can select another day, but we cannot scroll months.

更新2

我想这是一个新的Android DatePicker的错误.因此，我必须选择著名的库 https://github.com/wdullaer/MaterialDateTimePicker .它会选择一个指定的日期，而无需更改原始主题.

I suppose this is a bug of a new Android DatePicker. So I have to select well-known library https://github.com/wdullaer/MaterialDateTimePicker. It selects a specified date right and doesn't require changing an original theme.

推荐答案

您可以使用方法 constraintsBuilder.setOpenAt() 设置选择器打开的月份. 如果在界限内，则默认值为当前月份，否则在界限内为最​​早的月份:

You can set the month to which the picker opens with the method constraintsBuilder.setOpenAt(). The default value is the current month if within the bounds otherwise the earliest month within the bounds:

CalendarConstraints.Builder constraintsBuilder = new CalendarConstraints.Builder();

LocalDateTime local = LocalDateTime.of(2020, 11, 1, 0, 0);
long openAt= local.atZone(ZoneId.ofOffset("UTC", ZoneOffset.UTC)).toInstant().toEpochMilli();
//you can also use Calendar.getInstance()...
constraintsBuilder.setOpenAt(openAt);

builder.setCalendarConstraints(constraintsBuilder.build());

您可以使用以下方法设置默认选择(默认为无选择):

You can set a default selection (defaults to no selection) with:

builder.setSelection(....);

这篇关于MaterialDatePicker显示当前日期，而不是需要的日期的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！