团队——和谐共生（2）

和谐共生（2）

由于这学期的时间比较紧迫，所以是边学边做

今天学习了ViewPager和fragment,使用这两个知识做出了我们app的首页，效果图是这样的

 

 

 

 

项目结构目前是这样的

 

 

 

package com.example.peace;

//登录之后进入的界面

import androidx.appcompat.app.AppCompatActivity;

import androidx.fragment.app.Fragment;

import androidx.viewpager2.widget.ViewPager2;

 

import android.os.Bundle;

import android.view.View;

import android.widget.ImageView;

import android.widget.LinearLayout;

 

import java.util.ArrayList;

import java.util.List;

 

public class BrowerActivity extends AppCompatActivity implements View.OnClickListener {

    ViewPager2 viewPager;

    private LinearLayout lbrow,ldialog,lgame;

    private ImageView ivBrow,ivDialog,ivGame,ivCurrent;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_brower);

 

        //初始化ViewPager

        initPager();

        initTabView();

    }

 

    private void initTabView() {

        lbrow=findViewById(R.id.tab_brow);

        lbrow.setOnClickListener(this);

        ldialog=findViewById(R.id.tab_dialog);

        ldialog.setOnClickListener(this);

        lgame=findViewById(R.id.tab_game);

        lgame.setOnClickListener(this);

        ivBrow=findViewById(R.id.tab_iv_brow);

        ivDialog=findViewById(R.id.tab_iv_dialog);

        ivGame=findViewById(R.id.tab_iv_game);

 

        ivBrow.setSelected(true);

        ivCurrent=ivBrow;

    }

 

    private void initPager() {

        viewPager=findViewById(R.id.viewpager);

        ArrayList<Fragment> fragments=new ArrayList<>();

        fragments.add(BlankFragment.newInstance("浏览"));

        fragments.add(BlankFragment.newInstance("讨论"));

        fragments.add(BlankFragment.newInstance("娱乐一把"));

        PagerAdapter pagerAdapter=new PagerAdapter(getSupportFragmentManager(),getLifecycle(),fragments);

        viewPager.setAdapter(pagerAdapter);

        viewPager.registerOnPageChangeCallback(new ViewPager2.OnPageChangeCallback() {

            @Override

            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

                super.onPageScrolled(position, positionOffset, positionOffsetPixels);

            }

 

            @Override

            public void onPageSelected(int position) {

                super.onPageSelected(position);

                changeTab(position);

            }

 

            @Override

            public void onPageScrollStateChanged(int state) {

                super.onPageScrollStateChanged(state);

            }

        });

    }

 

    private void changeTab(int position) {

        ivCurrent.setSelected(false);

        switch (position){

            case R.id.tab_brow:

                viewPager.setCurrentItem(0);

            case 0:ivBrow.setSelected(true);

                ivCurrent=ivBrow;

                break;

            case R.id.tab_dialog:

                viewPager.setCurrentItem(1);

            case 1:ivDialog.setSelected(true);

                ivCurrent=ivDialog;

                break;

            case R.id.tab_game:

                viewPager.setCurrentItem(2);

            case 2:ivGame.setSelected(true);

                ivCurrent=ivGame;

                break;

        }

    }

 

    @Override

    public void onClick(View view) {

        changeTab(view.getId());

    }

}

 

package com.example.peace;

 

import android.os.Bundle;

 

import androidx.fragment.app.Fragment;

 

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.TextView;

 

/**

 * A simple {@link Fragment} subclass.

 * Use the {@link BlankFragment#newInstance} factory method to

 * create an instance of this fragment.

 */

public class BlankFragment extends Fragment {

 

    private static final String ARG_PARAM1 = "param1";

    View rootView;

 

    // TODO: Rename and change types of parameters

    private String mText;

 

    public BlankFragment() {

        // Required empty public constructor

    }

 

    // TODO: Rename and change types and number of parameters

    public static BlankFragment newInstance(String param1) {

        BlankFragment fragment = new BlankFragment();

        Bundle args = new Bundle();

        args.putString(ARG_PARAM1, param1);

        fragment.setArguments(args);

        return fragment;

    }

 

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        if (getArguments() != null) {

            mText = getArguments().getString(ARG_PARAM1);

        }

    }

 

    @Override

    public View onCreateView(LayoutInflater inflater, ViewGroup container,

                             Bundle savedInstanceState) {

        // Inflate the layout for this fragment

        if (rootView==null){

            rootView = inflater.inflate(R.layout.fragment_blank, container, false);

        }

        initView();

        return rootView;

    }

 

    private void initView() {

        TextView textView=rootView.findViewById(R.id.text);

        textView.setText(mText);

    }

}

<include layout="@layout/bottom_layout"/>
<!--必须要在MainActivity中引入bottom文件-->