【Android,kotlin】不再生硬!多Fragment切换的解决方案

青旅半醒 2022-10-12 14:59 251阅读 0赞

### Fragment切换的解决方案 ###

> **效果**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjQ3MzIyOA_size_16_color_FFFFFF_t_70]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjQ3MzIyOA_size_16_color_FFFFFF_t_70 1]  
点击左右划皆可,非常的丝滑…

> **底层**

`adapter`

open class TabAdapterMK(private val tabList: List<Fragment>, fragmentManager: FragmentManager) :
        FragmentPagerAdapter(fragmentManager) {
        override fun getCount() = tabList.size
    
        override fun getItem(position: Int): Fragment = tabList[position]
    }

> **Kotlin代码 (activity,fragment)**

`initView <- onCreate()`

//点击事件注册
    vb.mainTab1.setOnClickListener(this)
    vb.mainTab2.setOnClickListener(this)
    initFragmentPager()

`Viewpaper初始化`

private fun initFragmentPager() {
    	val tabList = arrayListOf<Fragment>(FragmentOne(), FragmentTwo())
        val adapterMK = TabAdapterMK(tabList, supportFragmentManager)
        vb.mainViewpager.adapter = adapterMK
        vb.mainViewpager.setOnPageChangeListener(object : ViewPager.OnPageChangeListener {
        	override fun onPageScrolled(position: Int,positionOffset: Float,positionOffsetPixels: Int) {}
    		override fun onPageSelected(position: Int) {
            	when (position) {
                	1 -> {vm.uiSelectedTab.setValue(1)}
    				else -> {vm.uiSelectedTab.setValue(0)}
    			}
    		}
            override fun onPageScrollStateChanged(state: Int) {}
    	})
    }

`onClick:`

override fun onClick(v: View?) {
    	when (v?.id) {
        	R.id.main_tab_1 -> {
            	vb.mainViewpager.setCurrentItem(0, false)}
    		R.id.main_tab_2 -> {
            	vb.mainViewpager.setCurrentItem(1, false)
    		}
    	}
    }

> **布局**

`activity_main`

<?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:toolbar="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools">
    
        <data>
    
            <variable
                name="vm"
                type="com.mozhimen.app.MainViewModel" />
        </data>
    
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:gravity="center"
            android:orientation="vertical">
    
            <androidx.viewpager.widget.ViewPager
                android:id="@+id/main_viewpager"
                android:layout_width="match_parent"
                android:layout_height="0dp"
                android:layout_weight="13"
                app:layout_behavior="@string/appbar_scrolling_view_behavior" />
    
            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="0dp"
                android:layout_weight="1"
                android:orientation="horizontal">
    
                <TextView
                    android:id="@+id/main_tab_1"
                    android:layout_width="0dp"
                    android:layout_height="match_parent"
                    android:layout_weight="1"
                    android:background="@{vm.uiSelectedTab==0?@color/lightBlue:@color/white}"
                    android:gravity="center"
                    android:text="one"
                    tools:ignore="HardcodedText" />
    
                <TextView
                    android:id="@+id/main_tab_2"
                    android:layout_width="0dp"
                    android:layout_height="match_parent"
                    android:layout_weight="1"
                    android:background="@{vm.uiSelectedTab==1?@color/lightBlue:@color/white}"
                    android:gravity="center"
                    android:text="two"
                    tools:ignore="HardcodedText" />
    
            </LinearLayout>
        </LinearLayout>
    </layout>

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjQ3MzIyOA_size_16_color_FFFFFF_t_70]: /images/20221005/106c92d86dd64d7aab9fe9fe0806de9a.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjQ3MzIyOA_size_16_color_FFFFFF_t_70 1]: /images/20221005/0cdbaa9e6c2b4c5590ae9a98c4bbb64f.png