ViewPager+Fragment的结合使用

<RadioGroup
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_weight="1">
<RadioButton
android:id="@+id/but1_main"
android:button="@null"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:textSize="40dp"
android:text="页面一"/>
<RadioButton
android:id="@+id/but2_main"
android:button="@null"
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="40dp"
android:text="页面二"/>
<RadioButton
android:id="@+id/but3_main"
android:button="@null"
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="40dp"
android:text="页面三"/>
<RadioButton
android:id="@+id/but4_main"
android:button="@null"
android:layout_weight="1"
android:textSize="40dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="页面四"/>
</RadioGroup>
<android.support.v4.view.ViewPager
android:id="@+id/vp_main"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="10">
</android.support.v4.view.ViewPager>

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

private RadioGroup group;
private RadioButton but1;
private RadioButton but2;
private ViewPager vp;
private ArrayList<RadioButton> butlist;
private RadioButton but3;
private RadioButton but4;
private ImageView image;

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

private void initView() {
but1= (RadioButton) findViewById(R.id.but1_main);
but2= (RadioButton) findViewById(R.id.but2_main);
but3 = (RadioButton) findViewById(R.id.but3_main);
but4 = (RadioButton) findViewById(R.id.but4_main);
butlist = new ArrayList<>();
butlist.add(but1);
butlist.add(but2);
butlist.add(but3);
butlist.add(but4);

//遍历所有的按钮，都设置点击监听事件
for (Button b: butlist) {
b.setOnClickListener(this);
}
vp = (ViewPager) findViewById(R.id.vp_main);
//因为myfragmentadapter需要一个fragmentmanager，所以创建出来传过去。
FragmentPagerAdapter myFragmentAdapter = new FragmentAdapter(getSupportFragmentManager());//给一个管理者
vp.setAdapter(myFragmentAdapter);
vp.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {

public void onPageSelected(int arg0) {
//循环遍历所有的button
//如果当前索引值和某一个but集合中的索引值一致，就讲该but颜色设置红色，其余的为黑色
for (int i = 0; i < butlist.size(); i++) {
if (i==arg0) {
butlist.get(i).setTextColor(Color.RED);
}else {
butlist.get(i).setTextColor(Color.BLACK);
}
}
}

public void onPageScrolled(int arg0, float arg1, int arg2) {

}

public void onPageScrollStateChanged(int arg0) {

}
});
}

@Override
public void onClick(View v) {
switch (v.getId()) {
//根据点钟but的索引值ID来判断哪一个but被点击，设置当前所在的页面。
case R.id.but1_main:
vp.setCurrentItem(0);
break;
case R.id.but2_main:
vp.setCurrentItem(1);
break;
case R.id.but3_main:
vp.setCurrentItem(2);
break;
case R.id.but4_main:
vp.setCurrentItem(3);
break;
default:
break;
}
}
}

public class FragmentAdapter extends FragmentPagerAdapter {

public FragmentAdapter(FragmentManager fm) {
super(fm);
// TODO Auto-generated constructor stub
}

@Override
public Fragment getItem(int position) {
Fragment fragment=null;
switch (position) {
case 0:
fragment=new Fragment1();
break;
case 1:
fragment=new Fragment2();
break;
case 2:
fragment=new Fragment3();
break;
case 3:
fragment=new Fragment4();
break;
default:
break;
}
return fragment;
}
//界面
@Override
public int getCount() {
return 4;
}

}

public class Fragment1 extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.f1,null);
}

@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
}