Android Jetpack 之Navigation Architecture Component使用

时间 2019-11-17

标签 android jetpack navigation architecture component 使用栏目 Android 繁體版

原文原文链接

在刚刚结束的谷歌IO大会上，谷歌推出了Android Jetpack架构组件；正如官网所说，Android Jetpack 是一套组件、工具和指导，能够帮助您构建出色的 Android 应用。Android Jetpack 组件将现有的支持库与架构组件联系起来，并将它们分红四个类别：Architecture、Foundation、Behavior 以及 UI。他可以让开发者创造出更加出色的高质量应用。java

Navigation Architecture Component 介绍

Navigation导航编辑器做为Android Jetpack和 AndroidX 依赖库的一部分其目标旨在简化Android开发中导航的实现。Navigation能够帮助咱们很好的处理Activity和fragment之间经过FragmentTransaction交互的复杂性。另外Navigation也能够很好的处理页面的转场效果。固然熟悉IOS开发的同窗确定看到这确定会以为这不就是StoryBoard么。关于Navigation的介绍，谷歌官方介绍的也不是很详细（英语太差~~~）,那么咱们就动手实现个吧!!!android

Navigation 使用

建立Android Jetpack 应用（Android Studio 3.2 Canary 13及更高版本）

添加依赖

项目的build.gradle:

buildscript {
	...
	repositories {
    		google()
	}
	dependencies {
    		...
    		classpath 'android.arch.navigation:navigation-safe-args-gradle-plugin:1.0.0-alpha01'
	}
}

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在app的build.gradle中添加以下依赖:

apply plugin: 'androidx.navigation.safeargs'
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implementation 'android.arch.navigation:navigation-fragment:1.0.0-alpha01'
implementation 'android.arch.navigation:navigation-ui:1.0.0-alpha01'
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建立导航编辑器

右键res资源文件夹： New -> Android resource file -> 输入xml文件名称并选择Resource type为Navigation -> OKgit

<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android">

</navigation>
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给Activity添加导航视图

因为Navigation 中须要将fragment视图和activity绑定，那么接下来改造吧：github

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">


    <fragment
        android:id="@+id/my_nav_host_fragment"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:defaultNavHost="true"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="1"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="1"
        app:navGraph="@navigation/main_navigation" />

</android.support.constraint.ConstraintLayout>
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activity中fragment默认为NavHostFragment，NavHostFragment经过navGraph与navigation导航编辑器进行关联。 app:defaultNavHost="true"可让NavHostFragment处理系统的返回事件bash

编辑Navigation导航视图

<?xml version="1.0" encoding="utf-8"?>
<navigation 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"
    app:startDestination="@+id/main_fragment">


    <fragment
        android:name="com.wangjun.app.jetpacktodolist.ui.main.MainFragment"
        android:id= "@+id/main_fragment"
        android:label="@string/main_fragment_title"
        tools:layout="@layout/main_fragment">


    </fragment>


    <activity
        android:id="@+id/settings_activity"
        android:name="com.wangjun.app.jetpacktodolist.ui.SettingActivity"
        android:label="@string/activity_settings"
        tools:layout="@layout/setting_activity"
        />

</navigation>

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咱们看到navigation标签声明了一个app:startDestination="@+id/main_fragment"属性，他是导航器默认加载的视图架构

Navigation 跳转-- Action

如今咱们看到咱们的导航编辑器又两个视图，main_fragment和 settings_activity，咱们如今须要从main_fragment中跳转到 settings_activity的话，能够给main_fragment添加action标签来完成跳转app

<?xml version="1.0" encoding="utf-8"?>
<navigation 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"
    app:startDestination="@+id/main_fragment">


    <fragment
        android:name="com.wangjun.app.jetpacktodolist.ui.main.MainFragment"
        android:id= "@+id/main_fragment"
        android:label="@string/main_fragment_title"
        tools:layout="@layout/main_fragment">

        <!--跳转到SettingActivity-->
        <action
            android:id="@+id/action_main_fragment_to_settings_activity"
            app:destination="@id/settings_activity" />

    </fragment>


    <activity
        android:id="@+id/settings_activity"
        android:name="com.wangjun.app.jetpacktodolist.ui.SettingActivity"
        android:label="@string/activity_settings"
        tools:layout="@layout/setting_activity"
        />

</navigation>
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action标签中的app:destination就是咱们要加载导航的视图编辑器

固然咱们也能够在导航编辑器中经过拖动来完成ide

接下来咱们在MainFragment中添加一个按钮来完成跳转SettingActivity工具

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ui.main.MainFragment">

    <android.support.v7.widget.AppCompatButton
        android:id="@+id/btn_setting"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.5" />

</android.support.constraint.ConstraintLayout>

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class MainFragment : Fragment() {

    companion object {
        fun newInstance() = MainFragment()
    }

    private lateinit var viewModel: MainViewModel

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                              savedInstanceState: Bundle?): View {
        val view = inflater.inflate(R.layout.main_fragment, container, false)

        view.findViewById<AppCompatButton>(R.id.btn_setting).setOnClickListener {
            Navigation.findNavController(view).navigate(R.id.action_main_fragment_to_settings_activity)
        }


        return view
    }
}
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咱们看到经过Navigation.findNavController(view)获得一个NavController,经过NavController.navigate(R.id.xxxx) 会对应到当前View的某个Action，这样咱们就能够跳转了。是否是很简单~~~

添加转场动画添加转场动画也很简单，咱们只须要在action添加以下属性

<fragment
        android:name="com.wangjun.app.jetpacktodolist.ui.main.MainFragment"
        android:id= "@+id/main_fragment"
        android:label="@string/main_fragment_title"
        tools:layout="@layout/main_fragment">

        <action
            app:popEnterAnim="@anim/slide_in_left"
            app:popExitAnim="@anim/slide_out_right"
            app:enterAnim="@anim/slide_in_right"
            app:exitAnim="@anim/slide_out_left"
            android:id="@+id/action_main_fragment_to_settings_activity"
            app:destination="@id/settings_activity" />

</fragment>
    
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传递数据

和之前同样咱们能够经过bundle传递数据

代码中手写

<fragment
        android:id="@+id/main2_fragment"
        android:name="com.wangjun.app.jetpacktodolist.ui.main.Main2Fragment"
        android:label="@string/main2_fragment_title"
        tools:layout="@layout/main2_fragment">

        <argument android:name="testArg"
            app:type="string"
            android:defaultValue="Hello Leon"
            />

        <argument
            android:name="testArg2"
            android:defaultValue="大王叫我来巡山"
            app:type="string" />

</fragment>

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导航编辑器添加

MainFragment传参到 Main2Fragment

class MainFragment : Fragment() {

    companion object {
        fun newInstance() = MainFragment()
    }

    private lateinit var viewModel: MainViewModel

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                              savedInstanceState: Bundle?): View {
        val view = inflater.inflate(R.layout.main_fragment, container, false)

        view.findViewById<AppCompatButton>(R.id.btn_setting).setOnClickListener {
            Navigation.findNavController(view).navigate(R.id.action_main_fragment_to_settings_activity)
        }


        /**
         * 参数跳转
         */
        view.findViewById<AppCompatButton>(R.id.btn_main2).setOnClickListener {

            val bundle = bundleOf("testArg" to "很高兴碰见你",
                    "testArg2" to "你是猴子派来的逗逼吗")
            Navigation.findNavController(view).navigate(
                    R.id.action_main_fragment_to_main2_fragment,
                    bundle)
        }

        return view
    }

    override fun onActivityCreated(savedInstanceState: Bundle?) {
        super.onActivityCreated(savedInstanceState)
        viewModel = ViewModelProviders.of(this).get(MainViewModel::class.java)

    }

}
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class Main2Fragment : Fragment() {

    private lateinit var testArg: String
    private lateinit var testArg2: String

    companion object {
        fun newInstance() = Main2Fragment()
    }

    @SuppressLint("SetTextI18n")
    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                              savedInstanceState: Bundle?): View {
        val view = inflater.inflate(R.layout.main2_fragment, container, false)

        arguments?.let {
            testArg = it["testArg"] as String
            testArg2 = it["testArg2"] as String
        }

        var tvMain = view.findViewById<AppCompatTextView>(R.id.tv_main)

        tvMain.text = "$testArg---$testArg2"

        return view
    }

}
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咱们发现传参是经过NavController 来传递的，具体源码以下：

NavController.java

 /**
     * Navigate to a destination from the current navigation graph. This supports both navigating
     * via an {@link NavDestination#getAction(int) action} and directly navigating to a destination.
     *
     * @param resId an {@link NavDestination#getAction(int) action} id or a destination id to
     *              navigate to
     * @param args arguments to pass to the destination
     */
    public final void navigate(@IdRes int resId, @Nullable Bundle args) {
        navigate(resId, args, null);
    }
    
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深层连接 deep-link

其实很好理解的，也就是咱们之前所说的自定义URL使用Scheme方式来跳转传参

navigation.xml

<navigation>
    <activity
        android:id="@+id/settings_activity"
        android:name="com.wangjun.app.jetpacktodolist.ui.SettingActivity"
        android:label="@string/activity_settings"
        tools:layout="@layout/setting_activity" >

        <!--深层连接-->
        <deepLink app:uri="www.leonwang.com/hello/{testArg}" />

    </activity>

</navigation>
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AndroidManifest.xml

<activity
            android:name=".ui.SettingActivity"
            android:label="@string/activity_settings">

            <intent-filter>
                <action android:name="android.intent.action.VIEW"/>
                <category android:name="android.intent.category.DEFAULT"/>
                <category android:name="android.intent.category.BROWSABLE"/>
                <data android:scheme="https"/>
                <data android:scheme="http"/>
                <data android:host="www.leonwang.com"/>
                <data android:pathPrefix="/hello/"/>
            </intent-filter>

</activity>

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注意

根据官方文档说明，为了保证导航的正确使用，咱们须要在目标的Activity中重写onSupportNavigateUp，以确保导航器可以正确的回退栈。

override fun onSupportNavigateUp(): Boolean {
	return navController.navigateUp()
}
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最后

好了，导航组件基本的使用就这么多，DEMO。关于更加详细的介绍，请参考官方文档说明