26.Activity发送信息给Fragment

安卓序列化知识点：

javabean如何传值，javabean没有办法直接传值，但是可以通过把javabean变成某一个key，key对应的是Parcelable，Parcelable就可以携带javabean

一、Activity与Fragment通信

原生方案：Bundle（相当于一个通信工具，可以保存数据的一个android里面独立的类，这个独立的类就可以进行一个通信的数据的载体）

二、实现步骤

1.在Activity中进行传值

2.在Fragment中接收Activity传过来的值

三、整体代码

1.MainActivity文件代码

package com.example.fragmentmanagers;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import com.example.fragmentmanagers.fragment.BlankFragment1;
import com.example.fragmentmanagers.fragment.BlankFragment2;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button btn_one = findViewById(R.id.btn_one);
        btn_one.setOnClickListener(this);
        Button btn_two = findViewById(R.id.btn_two);
        btn_two.setOnClickListener(this);
    }
    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_one:
                Bundle bundle = new Bundle();
                bundle.putString("message","我很喜欢享学课堂");
                BlankFragment1 blankFragment1 = new BlankFragment1();
                blankFragment1.setArguments(bundle);
                replaceFragment(blankFragment1);
                break;
            case R.id.btn_two:
                replaceFragment(new BlankFragment2());
        }
    }
    //动态切换fragment
    private void replaceFragment(Fragment fragment) {
        FragmentManager fragmentManager = getSupportFragmentManager();
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        transaction.replace(R.id.fl_item,fragment);
        transaction.addToBackStack(null);
        transaction.commit();
    }
}

2.BlankFragment1文件代码

package com.example.fragmentmanagers.fragment;
import android.os.Bundle;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentActivity;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.example.fragmentmanagers.R;
public class BlankFragment1 extends Fragment {
    private static final String TAG = "BlankFragment1";
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Bundle bundle = getArguments();
        String message = bundle.getString("message");
        Log.e("he",""+message);
    }
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_blank_fragment1, container, false);
    }
}

3.效果图：