Drink-Order-System-master/RootActivity.java

package com.example.drink_order_system;

import android.annotation.SuppressLint;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.util.Log;
import android.widget.RadioButton;
import android.widget.RadioGroup;

import androidx.appcompat.app.AppCompatActivity;

public class RootActivity extends AppCompatActivity {

    private RadioGroup rg_tab_bar;
    private RadioButton rb_order;
    private Fragment fg_order; //点单界面
    private Fragment fg_mine; //个人信息界面
    private Fragment fg_bill; //查看历史订单界面
    private FragmentManager fManager;
    private String userName;

    @SuppressLint("MissingInflatedId")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_root);
        userName = getIntent().getStringExtra("userName");
        System.out.println("username in oncreate in rootActivity "+userName);
        fManager = getFragmentManager();
        rg_tab_bar = (RadioGroup) findViewById(R.id.rg_tab);
        rg_tab_bar.setOnCheckedChangeListener(this::onCheckedChanged); //对下方导航栏设置监听，实现界面切换
        //获取第一个单选按钮，并设置其为选中状态
        rb_order = (RadioButton) findViewById(R.id.rb_order);
        rb_order.setChecked(true);
        defaultFragment(); //将点单界面设为默认界面
    }

    public void defaultFragment()
    {
        FragmentTransaction fTransaction = fManager.beginTransaction();
        fg_order = new RestaurantFragment(userName);
        fTransaction.add(R.id.ly_content,fg_order);
        fTransaction.show(fg_order);
        fTransaction.commit();
    }

    public void onCheckedChanged(RadioGroup group, int checkedId) { //界面切换函数
        FragmentTransaction fTransaction = fManager.beginTransaction();
        hideAllFragment(fTransaction); //先隐藏所有界面
            switch (checkedId){
                case R.id.rb_order:
                    if(fg_order==null)
                    {
                        fg_order = (Fragment) new RestaurantFragment(userName);
                        fTransaction.add(R.id.ly_content,fg_order);
                        fTransaction.show(fg_order);
                    }
                    else
                        fTransaction.show(fg_order);
                    break;
                case R.id.rb_bill:
                    if(fg_bill==null)
                    {
                        fg_bill = BillFragment.newInstance(userName);
                        fTransaction.add(R.id.ly_content,fg_bill);
                        fTransaction.show(fg_bill);
                    }
                    else
                        fTransaction.show(fg_bill);
                    break;
                case R.id.rb_mine:
                    if(fg_mine==null)
                    {
                        fg_mine = MineFragment.newInstance(userName);
                    //    Log.e("fg_mine",userName);
                        fTransaction.add(R.id.ly_content,fg_mine);
                        fTransaction.show(fg_mine);
                    }
                    else
                        fTransaction.show(fg_mine);
                    break;
            }
        fTransaction.commit();
    }

    //隐藏所有Fragment
    private void hideAllFragment(FragmentTransaction fragmentTransaction){
        if(fg_order!=null)fragmentTransaction.hide(fg_order);
        if(fg_bill!=null)fragmentTransaction.hide(fg_bill);
        if(fg_mine!=null)fragmentTransaction.hide(fg_mine);
    }


}