ViewGroup.AddView（）正在工作，但儿童视图未显示

Question

我开发了一个Android应用。我想动态地将TextView添加到线性层次上。没有发生错误，但未显示文本视图。我认为Sleep_records_container的高度可能是0DP，我尝试设置300DP，但在此容器中没有显示任何内容。如何解决这个问题？

下面的片段旨在在一个月内显示睡眠记录。

SleepRecordFragment.kt

package com.example.sleeprecorder.sleeprecord

import android.annotation.SuppressLint

import android.os.Bundle
import android.util.Log
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.view.ViewGroup.LayoutParams
import android.widget.LinearLayout
import android.widget.TextView
import androidx.core.view.size
import androidx.fragment.app.Fragment
import androidx.lifecycle.Observer
import androidx.lifecycle.ViewModelProvider
import androidx.navigation.fragment.findNavController
import com.example.sleeprecorder.R
import com.example.sleeprecorder.database.SleepRecorderDatabase
import com.example.sleeprecorder.databinding.FragmentSleepRecordBinding
import java.text.SimpleDateFormat
import java.util.*

class SleepRecordFragment: Fragment() {
    @SuppressLint("SimpleDateFormat")
    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        Log.i("SleepRecordFragment", "onCreateView called")
        val binding = FragmentSleepRecordBinding.inflate(inflater, container, false)
        //val binding : FragmentSleepRecordBinding = DataBindingUtil.inflate(inflater, R.layout.fragment_sleep_record, container, false)

        val application = requireNotNull(this.activity).application
        val dataSource = SleepRecorderDatabase.getInstance(application).sleepRecordDao

        val viewModelFactory = SleepRecordViewModelFactory(dataSource, application)

        val sleepRecordViewModel = ViewModelProvider(this, viewModelFactory).get(SleepRecordViewModel::class.java)





        binding.sleepRecordViewModel = sleepRecordViewModel
        binding.setLifecycleOwner(this)

        sleepRecordViewModel.oneMonthSleepRecords.observe(this, Observer { oneMonthSleepRecords ->
            Log.i("SleepRecordFragment", "oneMonthSleepRecords.size: ${oneMonthSleepRecords.size}")

            binding.sleepRecordsContainer.removeAllViews()
            oneMonthSleepRecords.forEach { sleepRecord ->
                Log.i("SleepRecordFragment", "Observe oneMonthSleepRecords: ${sleepRecord.toString()}")



                val startSleepTextView = TextView(context)
                startSleepTextView.width = LayoutParams.WRAP_CONTENT
                startSleepTextView.height = LayoutParams.WRAP_CONTENT
                val startSleepDate = Date(sleepRecord!!.startTimeMilli)
                val formatter = SimpleDateFormat("yyyy/MM/dd HH:mm:ss")
                val startSleepText = getString(R.string.start_sleep_datetime, formatter.format(startSleepDate))
                startSleepTextView.text = startSleepText
                Log.i("SleepRecordFragment", "start sleep text: ${startSleepText}")

                val sleepRecordLinearLayout = LinearLayout(context)
                sleepRecordLinearLayout.orientation = LinearLayout.VERTICAL
                sleepRecordLinearLayout.addView(startSleepTextView)
                binding.sleepRecordsContainer.addView(sleepRecordLinearLayout)

            }

            Log.i("SleepRecordFragment", "size in sleep record container: ${binding.sleepRecordsContainer.size}")
        })



        val calendar = Calendar.getInstance()
        val thisYear = calendar.get(Calendar.YEAR)
        val thisMonthIndex = calendar.get(Calendar.MONTH)

        sleepRecordViewModel.setThisYearMonth(thisYear, thisMonthIndex)


        binding.yearMonth.text = getYearMonthStr(thisYear, thisMonthIndex)
        binding.yearMonth.setTag(R.id.year, thisYear)
        binding.yearMonth.setTag(R.id.month_index, thisMonthIndex)
        Log.i("SleepRecordFragment", "tag year: ${binding.yearMonth.getTag(R.id.year)}")
        Log.i("SleepRecordFragment", "tag month index ${binding.yearMonth.getTag(R.id.month_index)}")



        binding.addSleepRecord.setOnClickListener {
            this.findNavController().navigate(SleepRecordFragmentDirections.actionSleepRecordFragmentToAddSleepFragmentRecord())
        }

        binding.goToNextMonth.setOnClickListener {
            val shownYear = binding.yearMonth.getTag(R.id.year).toString().toInt()
            val shownMonthIndex = binding.yearMonth.getTag(R.id.month_index).toString().toInt()
            Log.i("SleepRecordFragment", "shownYear: ${shownYear}")
            Log.i("SleepRecordFragment", "shownMonthIndex: ${shownMonthIndex}")


            val calendarToNextMonth = Calendar.getInstance()
            calendarToNextMonth.set(Calendar.YEAR, shownYear)
            calendarToNextMonth.set(Calendar.MONTH, shownMonthIndex)
            calendarToNextMonth.add(Calendar.MONTH, 1)

            val yearMonthStr = getYearMonthStr(calendarToNextMonth.get(Calendar.YEAR), calendarToNextMonth.get(Calendar.MONTH))


            Log.i("SleepRecordFragment", "next month: ${yearMonthStr}")
            binding.yearMonth.text = yearMonthStr
            binding.yearMonth.setTag(R.id.year, calendarToNextMonth.get(Calendar.YEAR))
            binding.yearMonth.setTag(R.id.month_index, calendarToNextMonth.get(Calendar.MONTH))

            sleepRecordViewModel.onChangeMonth(calendarToNextMonth.get(Calendar.YEAR), calendarToNextMonth.get(Calendar.MONTH))
        }

        binding.goToPreviousMonth.setOnClickListener {
            val shownYear = binding.yearMonth.getTag(R.id.year).toString().toInt()
            val shownMonthIndex = binding.yearMonth.getTag(R.id.month_index).toString().toInt()
            val calendarToPreviousMonth = Calendar.getInstance()
            calendarToPreviousMonth.set(Calendar.YEAR, shownYear)
            calendarToPreviousMonth.set(Calendar.MONTH, shownMonthIndex)
            calendarToPreviousMonth.add(Calendar.MONTH, -1)

            val yearMonthStr = getYearMonthStr(calendarToPreviousMonth.get(Calendar.YEAR), calendarToPreviousMonth.get(Calendar.MONTH))
            binding.yearMonth.text = yearMonthStr
            binding.yearMonth.setTag(R.id.year, calendarToPreviousMonth.get(Calendar.YEAR))
            binding.yearMonth.setTag(R.id.month_index, calendarToPreviousMonth.get(Calendar.MONTH))

            sleepRecordViewModel.onChangeMonth(calendarToPreviousMonth.get(Calendar.YEAR), calendarToPreviousMonth.get(Calendar.MONTH))
        }





        return binding.root
    }

    private fun getYearMonthStr(year: Int, monthIndex: Int): String {
        val yearStr = year.toString()
        val monthStr = (monthIndex + 1).toString()
        val zeroPaddingMonthStr = "00${monthStr}".substring("00${monthStr}".length - 2)


        return "${yearStr}/${zeroPaddingMonthStr}"
    }


}

Fragment_sleep_record.xml

<?xml version="1.0" encoding="utf-8"?>
<layout
    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">
    <data>
        <variable
            name="sleepRecordViewModel"
            type="com.example.sleeprecorder.sleeprecord.SleepRecordViewModel" />

    </data>
    <ScrollView
        android:id="@+id/sleep_record_list"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">
            <androidx.constraintlayout.widget.ConstraintLayout
                android:id="@+id/year_month_navigation"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal">

                <TextView
                    android:id="@+id/go_to_previous_month"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/go_to_previous_month"
                    android:textSize="22sp"
                    app:layout_constraintTop_toTopOf="parent"
                    app:layout_constraintStart_toStartOf="parent"
                    app:layout_constraintEnd_toStartOf="@id/year_month"
                    />

                <TextView
                    android:id="@+id/year_month"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text=""
                    android:textSize="22sp"
                    app:layout_constraintTop_toTopOf="parent"
                    app:layout_constraintStart_toEndOf="@id/go_to_previous_month"
                    app:layout_constraintEnd_toStartOf="@id/go_to_next_month"/>


                <TextView
                    android:id="@+id/go_to_next_month"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/go_to_next_month"
                    android:textSize="22sp"
                    app:layout_constraintStart_toEndOf="@id/year_month"
                    app:layout_constraintEnd_toEndOf="parent"
                    app:layout_constraintTop_toTopOf="parent"
                    />
                <Button
                    android:id="@+id/add_sleep_record"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/add_sleep_record"
                    app:layout_constraintTop_toBottomOf="@id/year_month"
                    app:layout_constraintStart_toStartOf="parent"
                    app:layout_constraintEnd_toEndOf="parent"
                    />
            </androidx.constraintlayout.widget.ConstraintLayout>
        <LinearLayout
            android:id="@+id/sleep_records_container"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">
        </LinearLayout>


        </LinearLayout>
    </ScrollView>
</layout>

Answer 1

尝试设置wrap_content通过layoutparams，如下所示。

    val startSleepTextView = TextView(context)
    //startSleepTextView.width = LayoutParams.WRAP_CONTENT
    //startSleepTextView.height = LayoutParams.WRAP_CONTENT
    startSleepTextView.layoutParams = LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT)

Answer 2

您没有从代码中夸大它的布局：如果要设置绑定的布局，则可能想做类似的操作：

binding = Layout.inflate(inflator, container, false)

因为我不知道您正在使用哪种布局，所以我只是用通用布局代替。如果使用NAVI视图，您将获得与FragmentManager不同的答案。