Android大杂绘，写作业留下的，供参考

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private String TAG = MainActivity.class.getSimpleName();

    Button button1,button2,button3,button4,button5,button6;

    private ServiceConnection mServiceConnection;
    private DownloadBinder mDownloadBinder;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main4);

        button1 = findViewById(R.id.button1);
        button2 = findViewById(R.id.button2);
        button3 = findViewById(R.id.button3);
        button4 = findViewById(R.id.button4);
        button5 = findViewById(R.id.button5);
        button6 = findViewById(R.id.button6);

        button1.setOnClickListener(this);
        button2.setOnClickListener(this);
        button3.setOnClickListener(this);
        button4.setOnClickListener(this);
        button5.setOnClickListener(this);
        button6.setOnClickListener(this);

        mServiceConnection = new ServiceConnection() {
            @Override
            public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
                mDownloadBinder=(DownloadBinder) iBinder;
            }

            @Override
            public void onServiceDisconnected(ComponentName componentName) {

            }
        };

    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.button1:
                Intent startIntent = new Intent(this,MyService.class);
                startService(startIntent);
                break;
            case R.id.button2:
                Intent stopIntent = new Intent(this,MyService.class);
                stopService(stopIntent);
                break;
            case R.id.button3:
                Intent bindIntent = new Intent(this,MyService.class);
                bindService(bindIntent,mServiceConnection,BIND_AUTO_CREATE);
                break;
            case R.id.button4:
                unbindService(mServiceConnection);
                break;
            case R.id.button5:
                mDownloadBinder.startDownload();
                break;
            case R.id.button6:
                mDownloadBinder.getProgress();
                break;
        }
    }
}

public class MainActivity extends AppCompatActivity implements RadioGroup.OnCheckedChangeListener {

    private String TAG = MainActivity.class.getSimpleName();
    ViewPager viewpager;
    RadioButton rb1,rb2,rb3,rb4,rb5,rb6,rb7,curRb;
    RadioGroup radios;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);

        rb1 = findViewById(R.id.rb1);
        rb2 = findViewById(R.id.rb2);
        rb3 = findViewById(R.id.rb3);
        rb4 = findViewById(R.id.rb4);
        rb5 = findViewById(R.id.rb5);
        rb6 = findViewById(R.id.rb6);
        rb7 = findViewById(R.id.rb7);

        radios = findViewById(R.id.radios);

        radios.setOnCheckedChangeListener(this);

        viewpager = findViewById(R.id.viewpager);

        List<Fragment> fragmentList = new ArrayList<>();
        List<String> mTitleList = new ArrayList<>();
        for (int i=0;i<7;i++)
        {
            fragmentList.add(new Fragment());
            int x = i+1;
            mTitleList.add("第"+x+"个");
        }



        MyFragmentPageAdapter fragmentPageAdapter = new MyFragmentPageAdapter(getSupportFragmentManager(),0,fragmentList,mTitleList);
        viewpager.setAdapter(fragmentPageAdapter);

        viewpager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                Log.d(TAG, "onPageSelected: "+position);
                changeViewPager(position);
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });
        curRb  =rb1;
        changeViewPager(0);
    }

    private void changeViewPager(Integer Id) {
        curRb.setChecked(false);
        viewpager.setCurrentItem(Id);
        switch (Id)
        {
            case 0:
                curRb = rb1;
                break;
            case 1:
                curRb = rb2;
                break;
            case 2:
                curRb = rb3;
                break;
            case 3:
                curRb = rb4;
                break;
            case 4:
                curRb = rb5;
                break;
            case 5:
                curRb = rb6;
                break;
            case 6:
                curRb = rb7;
                break;
        }

        curRb.setChecked(true);
    }

    @Override
    public void onCheckedChanged(RadioGroup radioGroup, int i) {
        switch (i)
        {
            case R.id.rb1:
                if(rb1.isChecked()) {
                    changeViewPager(0);
                }
                break;
            case R.id.rb2:
                if(rb2.isChecked()) {
                    changeViewPager(1);
                }
                break;
            case R.id.rb3:
                if(rb3.isChecked()) {
                    changeViewPager(2);
                }
                break;
            case R.id.rb4:
                if(rb4.isChecked()) {
                    changeViewPager(3);
                }
                break;
            case R.id.rb5:
                if(rb5.isChecked()) {
                    changeViewPager(4);
                }
                break;
            case R.id.rb6:
                if(rb6.isChecked()) {
                    changeViewPager(5);
                }
                break;
            case R.id.rb7:
                if(rb7.isChecked()) {
                    changeViewPager(6);
                }
                break;
        }
    }
}

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private String TAG = MainActivity.class.getSimpleName();

    Button main_btn_1,main_btn_2,main_btn_3,main_btn_4;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main1);

        main_btn_1 = findViewById(R.id.main_btn_1);
        main_btn_2 = findViewById(R.id.main_btn_2);
        main_btn_3 = findViewById(R.id.main_btn_3);
        main_btn_4 = findViewById(R.id.main_btn_4);

        main_btn_1.setOnClickListener(this);
        main_btn_2.setOnClickListener(this);
        main_btn_3.setOnClickListener(this);
        main_btn_4.setOnClickListener(this);


    }

    @Override
    public void onClick(View view) {
        FragmentManager fragmentManager = getSupportFragmentManager();
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        switch (view.getId()){
            case R.id.main_btn_1:
                transaction.replace(R.id.main_fm,new Fragment1());
                break;
            case R.id.main_btn_2:
                transaction.replace(R.id.main_fm,new Fragment2());
                break;
            case R.id.main_btn_3:
                transaction.replace(R.id.main_fm,new Fragment3());
                break;
            case R.id.main_btn_4:
                transaction.replace(R.id.main_fm,new Fragment4());
                break;
        }
        transaction.commit();
    }
}


public class MainActivity extends AppCompatActivity {

    FrameLayout fra_title;
    FrameLayout fra_content;

    private String TAG = MainActivity.class.getSimpleName();


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

        fra_title = findViewById(R.id.fra_title);
        fra_content = findViewById(R.id.fra_content);

        FragmentManager fragmentManager = getSupportFragmentManager();
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        transaction.add(R.id.fra_title,new TitleFragment());

        transaction.add(R.id.fra_content,new ContentFragment());

        transaction.commit();
    }
}