底部导航切换fragment

app/src/main/res/layout/activity_square_moreview.xml

@@ -94,7 +94,7 @@
                 >
             </com.aranandroid.customview.squareview.SquareTextImage>
 
-            <com.aranandroid.customview.fragment.FragmentTop
+            <com.aranandroid.customview.fragment.FragmentBottom
                 android:id="@+id/fragment_top"
                 android:layout_width="match_parent"
                 android:layout_height="500dp">
@@ -131,7 +131,7 @@
                         android:text="H"
                         tools:ignore="MissingConstraints" />
                 </com.aranandroid.customview.squareview.SquareLinearLayout>
-            </com.aranandroid.customview.fragment.FragmentTop>
+            </com.aranandroid.customview.fragment.FragmentBottom>
         </LinearLayout>
     </ScrollView>
 </com.aranandroid.customview.title.TitleLayout>

customview/src/main/java/com/aranandroid/customview/fragment/FragmentBottom.kt

@@ -0,0 +1,116 @@
+package com.aranandroid.customview.fragment
+
+import android.app.Activity
+import android.content.Context
+import android.graphics.Canvas
+import android.util.AttributeSet
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.LinearLayout
+import android.widget.RadioButton
+import android.widget.RadioGroup
+import androidx.core.view.children
+import androidx.fragment.app.Fragment
+import androidx.fragment.app.FragmentActivity
+import androidx.fragment.app.FragmentManager
+import androidx.fragment.app.FragmentPagerAdapter
+import androidx.viewpager.widget.ViewPager
+import androidx.viewpager.widget.ViewPager.OnPageChangeListener
+import com.aranandroid.customview.R
+
+class FragmentBottom(context: Context?, attrs: AttributeSet?) : LinearLayout(context, attrs) {
+
+    var view:View
+
+    var radio:RadioGroup
+
+    var viewPager: ViewPager
+
+    var fragments: LinkedHashMap<Int,Fragment>? = null
+        set(value) {
+            field = value
+            radio.setOnCheckedChangeListener(RadioGroup.OnCheckedChangeListener { group, checkedId ->
+                fragments?.keys?.let {
+                    for ((i, key) in it.withIndex()) {
+                        if(checkedId == key){
+                            viewPager.setCurrentItem(i,true)
+                        }
+                    }
+                }
+            })
+            val fm: FragmentManager = (context as FragmentActivity).getSupportFragmentManager()
+            val myFragmentPagerAdapter =
+                fragments?.values?.toList()?.let { MyFragmentPagerAdapter(fm, it) } //new myFragmentPagerAdater记得带上两个参数
+            viewPager.adapter = myFragmentPagerAdapter
+            viewPager.offscreenPageLimit = 3
+            viewPager.addOnPageChangeListener(object : OnPageChangeListener{
+                override fun onPageScrollStateChanged(state: Int) {
+                }
+
+                override fun onPageScrolled(
+                    position: Int,
+                    positionOffset: Float,
+                    positionoffsetpixels: Int
+                ) {
+                }
+
+                override fun onPageSelected(position: Int) {
+                    fragments?.keys?.let {
+                        for ((i, key) in it.withIndex()) {
+                            if(position == i){
+                                radio.findViewById<RadioButton>(key).performClick()
+                            }
+                        }
+                    }
+                }
+            })
+        }
+
+    init {
+        view = LayoutInflater.from(context).inflate(R.layout.fragment_bottom, this, true)
+        radio = view.findViewById(R.id.radio)
+        viewPager = view.findViewById(R.id.pager)
+    }
+
+    constructor(context: Context?):this(context,null){
+
+    }
+
+    override fun dispatchDraw(canvas: Canvas?) {
+
+        super.dispatchDraw(canvas)
+//        addChildrenForAccessibility()
+        val children = children
+        for (child in children) {
+            if(child.id != R.id.fragment_top){
+                (child.parent as ViewGroup).removeView(child)
+                radio.addView(child)
+            }
+        }
+    }
+
+
+    class MyFragmentPagerAdapter(
+        fm: FragmentManager?,
+        list: List<Fragment>
+    ) :
+        FragmentPagerAdapter(fm!!,FragmentPagerAdapter.BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT) {
+        private val listfragment //创建一个List<Fragment>
+                : List<Fragment>
+
+        override fun getItem(arg0: Int): Fragment {
+            return listfragment[arg0] //返回第几个fragment
+        }
+
+        override fun getCount(): Int {
+            return listfragment.size //总共有多少个fragment
+        }
+
+        // 定义构造带两个参数
+        init {
+            listfragment = list
+        }
+    }
+
+}

customview/src/main/res/layout/fragment_bottom.xml

@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout 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:id="@+id/fragment_top"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <RadioGroup
+        android:id="@+id/radio"
+        android:layout_width="match_parent"
+        android:layout_height="50dp"
+        android:layout_alignParentBottom="true"
+        android:gravity="center_vertical"
+        android:orientation="horizontal"
+        app:layout_constraintBottom_toBottomOf="parent"
+        tools:ignore="MissingConstraints"></RadioGroup>
+
+    <androidx.viewpager.widget.ViewPager
+        android:id="@+id/pager"
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        app:layout_constraintBottom_toTopOf="@id/radio"
+        app:layout_constraintLeft_toLeftOf="parent"
+        app:layout_constraintRight_toRightOf="parent"
+        app:layout_constraintTop_toTopOf="parent"/>
+
+</androidx.constraintlayout.widget.ConstraintLayout>