package com.example.wechatinterfacechange;
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);
ImageView imageView1=(ImageView)findViewById(R.id.image1);
ImageView imageView2=(ImageView)findViewById(R.id.image2);
ImageView imageView3=(ImageView)findViewById(R.id.image3);
ImageView imageView4=(ImageView)findViewById(R.id.image4);
imageView1.setOnClickListener(l);
imageView2.setOnClickListener(l);
imageView3.setOnClickListener(l);
imageView4.setOnClickListener(l);
}
View.OnClickListener l=new View.OnClickListener() {
@Override
public void onClick(View v) {
FragmentManager fm=getFragmentManager();
FragmentTransaction ft=fm.beginTransaction();
Fragment fg=null;
switch (v.getId()){
case R.id.image1:
fg=new WeChat_Fragment();
break;
case R.id.image2:
fg=new Message_Fragment();
break;
case R.id.image3:
fg=new Find_Fragment();
break;
case R.id.image4:
fg=new Me_Fragment();
break;
default:
break;
}
ft.replace(R.id.fragment,fg);
ft.commit();
}
};
}
为什么我的fg老是显示出现错误,提示我androidx.fragment.app.Fragment无法转换为android.app.Fragment