默认构造函数被弃用，我在Adroid Studio中找不到碎片问题

Question

package com.example.fragm;

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import androidx.fragment.app.Fragment;

public class ControlFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        if (savedInstanceState != null) {

        }
        View myView = inflater.inflate(R.layout.controlfragment,
                container, false);
        return myView;
    }
    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);

    }

}

package com.example.fragm;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class AndresFragment extends Fragment {


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        if (savedInstanceState != null) {
// restore internal values if necessary
        }
        View myView1 = inflater.inflate(R.layout.andresfragment,
                container, false);
        return myView1;
    }
    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
    }
}

package com.example.fragm;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        if (savedInstanceState != null) {
            return;
        }
        ControlFragment myFragment = new ControlFragment();
        getSupportFragmentManager().beginTransaction().add(R.id.my_fragment_container, myFragment).commit();
    }
}

package com.example.fragm;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        if (savedInstanceState != null) {
            return;
        }
        AndresFragment myFragment = new AndresFragment();
        getSupportFragmentManager().beginTransaction().add(R.id.my_fragment_container, myFragment).commit();
    }
}

Answer 1

您的AndresFragment导入错误。

而不是：

import android.app.Fragment;

您应该使用：

import androidx.fragment.app.Fragment;