今天学习Fragment的时候，实例化继承Fragment的对象（RightFragment（）和RightFragment2（））的时候报错

Question

//这种错误只是在使用support-v4的时候出现，而使用android.app的时候就不会出错
//由于我使用的Android Studio 所以build.gradle中已经添加了appcompat-v7库的依赖
//会自动引入support-v4;

package com.example.myapplication;

import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.app.Fragment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        replaceFragment(new RightFragment());
        //在实例化RightFragment()的时候报错

        Button button = (Button)findViewById(R.id.button_1);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                switch (v.getId()) {
                    case R.id.button_1;
                    
                        replaceFragment(new RightFragment2());
                        //在实例化RightFragment2()的时候报错
                        
                        
                        break;
                    default:
                        break;
                }
            }
        });

    }

//replaceFragment方法
    private void replaceFragment(Fragment fragment){
        FragmentManager fragmentManager = getSupportFragmentManager();
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        transaction.replace(R.id.right_fragment,fragment);
        transaction.commit();
    }
}

由于是新手有些地方可能错误可能很明显还请口下留情

Answer 1

把activity的继承父类换成FragmentActivity试试