[移动开发]Android jetpack之navigation

前面看完了lifecycle，下面看navigation。
步骤1：引入库

    implementation 'androidx.navigation:navigation-fragment:2.3.1'
    implementation 'androidx.navigation:navigation-ui:2.3.1'

步骤2：res下新建navigation目录，再创建个nav_graph的xml

步骤3：创建fragment容器

<?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"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <fragment
        android:id="@+id/nav_host_fragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:name="androidx.navigation.fragment.NavHostFragment"
        app:defaultNavHost= "true"
        app:navGraph="@navigation/nav_graph"/>


</androidx.constraintlayout.widget.ConstraintLayout>

步骤4：编写nav_graph.xml，或者进行界面拖动操作，其中还可以进行选中进行添加参数

<?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"
    android:id="@+id/nav_gra"
    app:startDestination="@id/blankFragment">

    <fragment
        android:id="@+id/blankFragment"
        android:name="com.example.myjetpacktest.BlankFragment"
        android:label="fragment_blank"
        tools:layout="@layout/fragment_blank" >
        <action
            android:id="@+id/action_blankFragment_to_secondFragment"
            app:destination="@id/secondFragment"
            app:enterAnim="@anim/nav_default_enter_anim"
            app:exitAnim="@anim/nav_default_exit_anim"
            app:popEnterAnim="@anim/nav_default_pop_enter_anim"
            app:popExitAnim="@anim/nav_default_pop_exit_anim" />
    </fragment>
    <fragment
        android:id="@+id/secondFragment"
        android:name="com.example.myjetpacktest.SecondFragment"
        android:label="fragment_second"
        tools:layout="@layout/fragment_second" >
        <argument
            android:name="age"
            app:argType="integer"
            android:defaultValue="0" />
        <argument
            android:name="name"
            app:argType="string"
            android:defaultValue="li" />
    </fragment>
</navigation>

步骤5：参数常量

public class ConstantUtil {
    public static final String PARAMS_ONE = "params1";
    public static final String PARAMS_TWO = "params2";
}

步骤6：fragment携带参数跳转

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_blank, container, false);
        view.findViewById(R.id.tv_to_second_fragment).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Bundle bundle = new Bundle();
                bundle.putInt(PARAMS_ONE,10);
                bundle.putString(PARAMS_TWO,"liwenpeng");
                Navigation.findNavController(view).navigate(R.id.action_blankFragment_to_secondFragment,bundle);
            }
        });
        return view;
    }

SecondFragment去接收:

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getInt(ConstantUtil.PARAMS_ONE);
            mParam2 = getArguments().getString(ConstantUtil.PARAMS_TWO);
            Log.d(TAG,"onCreate mParam1:"+mParam1+" ;mParam2:"+mParam2);
        }
    }