Navigation2

这次有两方面：

1.动态参数传递

从Home页面输入一个数值，显示到Detial页面，要用到bundle

HomeFragmen

package com.example.navdemo2;


import android.os.Bundle;

import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;

import android.text.TextUtils;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import org.w3c.dom.Text;


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


    public HomeFragment() {
        // 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;
        button=getView().findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                EditText editText;
                editText=getView().findViewById(R.id.editText);
                String string=editText.getText().toString();
                if(TextUtils.isEmpty(string)){
                    Toast.makeText(getActivity(),"请输入名字！",Toast.LENGTH_LONG).show();;
                    return;

                }
                Bundle bundle=new Bundle();
                bundle.putString("my_name",string);
                NavController controller= Navigation.findNavController(view);
                controller.navigate(R.id.action_homeFragment_to_detailFragment,bundle);
            }
        });
    }
}

DetailFragment

package com.example.navdemo2;


import android.os.Bundle;

import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;


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


    public DetailFragment() {
        // 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);
        String string =getArguments().getString("my_name");
        TextView textView=getView().findViewById(R.id.textView);
        textView.setText(string);
    }
}