为什么这里会报错啊我实在不明白到底哪里写错了？求解详解必采纳

Question

package com.example.demo01;

import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;

import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //获取四个图片文件
        ImageView imageView1=findViewById(R.id.image1);
        ImageView imageView2=findViewById(R.id.image2);
        ImageView imageView3=findViewById(R.id.image3);
        ImageView imageView4=findViewById(R.id.image4);
        imageView1.setOnClickListener(l);
        imageView2.setOnClickListener(l);
        imageView3.setOnClickListener(l);
        imageView4.setOnClickListener(l);
        //设置监听器
    }
    View.OnClickListener l=new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            FragmentManager fm=getFragmentManager();
           FragmentTransaction ft=fm.beginTransaction();
            Fragment f=null;
            switch (v.getId()){
                case R.id.image1:
                    f=new Fragment1();
                    break;
                case R.id.image2:
                    f=new Fragment2();
                    break;
                case R.id.image3:
                    f=new Fragment3();
                    break;
                case R.id.image4:
                    f=new Fragment4();
                    break;
                default:
                    break;
            }
           ft.replace(R.id.fragment,f);
            ft.commit();
        }
    };
}

为什么这里会报错啊我实在不明白到底哪里写错了？求解详解必采纳

Answer 1

包引错了。
你Fragment是androidx下的，androidx.fragment.app.Fragment
FragmentTransaction却是原生的， android.app.FragmentTransaction，android.app.FragmentTransaction
要统一，androidx.fragment.app.FragmentTransaction;，androidx.fragment.app.FragmentManager