安卓基础（Navigation）

今天学习了简单的Navigation：页面导航。

页面导航的简单例子：

MainAcitivity：

package com.example.navigation;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import androidx.navigation.ui.NavigationUI;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        NavController navController = Navigation.findNavController(this,R.id.fragment);
        NavigationUI.setupActionBarWithNavController(this,navController);
    }

    @Override
    public boolean onSupportNavigateUp() {
        NavController navController = Navigation.findNavController(this,R.id.fragment);
        return navController.navigateUp();
    }
}

Home_Fragment:

package com.example.navigation;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;

import androidx.navigation.NavAction;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;

/**
 * A simple {@link Fragment} subclass.
 */
public class Home_Fragment extends Fragment {

    public Home_Fragment() {
        // Required empty public constructor
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_home_, container, false);
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        Button button = getView().findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                NavController navController = Navigation.findNavController(v);
                navController.navigate(R.id.action_home_Fragment_to_detail_Fragment);
            }
        });
    }
}

Detail_Fragment:

package com.example.navigation;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;

import androidx.navigation.NavController;
import androidx.navigation.Navigation;

/**
 * A simple {@link Fragment} subclass.
 */
public class Detail_Fragment extends Fragment {

    public Detail_Fragment() {
        // Required empty public constructor
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_detail_, container, false);
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
//        Button button = getView().findViewById(R.id.button2);
//        button.setOnClickListener(new View.OnClickListener() {
//            @Override
//            public void onClick(View v) {
//                NavController navController = Navigation.findNavController(v);
//                navController.navigate(R.id.action_detail_Fragment_to_home_Fragment);
//            }
//        });
        getView().findViewById(R.id.button2).setOnClickListener(Navigation.createNavigateOnClickListener(R.id.action_detail_Fragment_to_home_Fragment));//上方注释的整体写法，功能一样
    }
}

home_detail截图：

这个项目就是简单的跳转，

点击HOME按钮跳转到Detail

按DETAIL按钮或者左上方的返回箭头均可返回到HOME页面