Activity要繼承FragementActivity，在Activity的佈局文件中放入了一個ViewPager，爲了效果好看，還做了個導航，使得ViewPager和導航欄能夠實現聯動，即ViewPager滑動切換頁面和點擊導航欄切換頁面，導航欄我使用的RadioButton，也可以使用其他的。
首先，我們需要在主佈局文件中activity_main.xml 放一個 ViewPager，底部導航欄使用RedioButton切換頁面，每一個RadioButton都使用了選擇器進行圖片與字體的變化。
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.lin.ui.MainActivity"
android:weightSum="9">
<android.support.v4.view.ViewPager
android:id="@+id/vp_viewpager"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="7.5"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1.5"
android:gravity="center"
android:orientation="horizontal">
<RadioGroup
android:id="@+id/radioGroup"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:orientation="horizontal">
<RadioButton
android:id="@+id/rb_a"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_gravity="right"
android:layout_weight="1"
android:button="@null"
android:checked="true"
android:drawableTop="@drawable/rabtn_a_selector"
android:textColor="@drawable/rabtn_a_selector"
android:gravity="center"
android:text="首頁"/>
<RadioButton
android:id="@+id/rb_b"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:button="@null"
android:checked="false"
android:drawableTop="@drawable/rabtn_b_selector"
android:textColor="@drawable/rabtn_b_selector"
android:gravity="center"
android:text="購物車"/>
<RadioButton
android:checked="false"
android:id="@+id/rb_c"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:button="@null"
android:drawableTop="@drawable/rabtn_c_selector"
android:textColor="@drawable/rabtn_c_selector"
android:gravity="center"
android:text="消息"/>
<RadioButton
android:checked="false"
android:id="@+id/rb_d"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_gravity="center"
android:layout_weight="1"
android:button="@null"
android:drawableTop="@drawable/rabtn_d_selector"
android:textColor="@drawable/rabtn_d_selector"
android:gravity="center"
android:text="我的"/>
</RadioGroup>
</LinearLayout>
</LinearLayout>
四個相同選擇器文件rabtn_a_selector.xml
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@drawable/a_0" android:state_checked="false" android:color="@color/gray"/>
<item android:drawable="@drawable/a_1" android:state_checked="true" android:color="@color/bule"/>
</selector>
package com.lin.ui;
import java.util.ArrayList;
import com.lin.adapter.MyViewPager;
import com.test.fragment.FragmentA;
import com.test.fragment.FragmentB;
import com.test.fragment.FragmentC;
import com.test.fragment.FragmentD;
import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;
public class MainActivity extends FragmentActivity {
/**
* 導航按鈕
*/
private RadioGroup radioGroup;
/**
* 作爲頁面容器的ViewPager
*/
private ViewPager vp_viewpager;
/**
* 頁面集合
*/
private ArrayList<Fragment> arrayList;
/**
* 四個Fragment（頁面）
*/
private FragmentA a;
private FragmentB b;
private FragmentC c;
private FragmentD d;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
}
@SuppressWarnings("deprecation")
private void initView() {
arrayList=new ArrayList<Fragment>();
a=new FragmentA();
arrayList.add(a);
b=new FragmentB();
arrayList.add(b);
c=new FragmentC();
arrayList.add(c);
d=new FragmentD();
arrayList.add(d);
vp_viewpager=(ViewPager) findViewById(R.id.vp_viewpager);
vp_viewpager.setAdapter(new MyViewPager(getSupportFragmentManager(), arrayList));
vp_viewpager.setCurrentItem(0); //設置當前頁是第一頁.setCurrentItem(0); //設置當前頁是第一頁
vp_viewpager.setOnPageChangeListener(new OnPageChangeListener() {
@Override
public void onPageSelected(int arg0) {
switch (arg0) {
case 0:
radioGroup.check(R.id.rb_a);
break;
case 1:
radioGroup.check(R.id.rb_b);
break;
case 2:
radioGroup.check(R.id.rb_c);
break;
case 3:
radioGroup.check(R.id.rb_d);
break;
default:
break;
}
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
// TODO Auto-generated method stub
}
@Override
public void onPageScrollStateChanged(int arg0) {
// TODO Auto-generated method stub
}
});
radioGroup=(RadioGroup) findViewById(R.id.radioGroup);
radioGroup.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup group, int arg1) {
//遍歷RadioGroup 裏面所有的子控件。
for (int index = 0; index < group.getChildCount(); index++) {
//獲取到指定位置的RadioButton
RadioButton rb = (RadioButton)group.getChildAt(index);
//如果被選中
if (rb.isChecked()) {
vp_viewpager.setCurrentItem(index);
break;
}
}
}
});
}
}
package com.test.fragment;
import com.lin.ui.R;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class FragmentA extends Fragment{
private View view;
// 單例(方法二)
private static FragmentA fa;
public static FragmentA getFragmentA() {
if (fa == null) {
fa = new FragmentA();
}
return fa;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
view= inflater.inflate(R.layout.fragment_a, container, false);
return view;
}
}
自定義一個ViewPager的適配器
package com.lin.adapter;
import java.util.ArrayList;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
public class MyViewPager extends FragmentPagerAdapter{
private ArrayList<Fragment> arrayList;
private FragmentManager fm; //創建FragmentManager
public MyViewPager(FragmentManager fm,ArrayList<Fragment> arrayList) {
super(fm);
this.arrayList=arrayList;
this.fm=fm;
}
@Override
public Fragment getItem(int arg0) {
return arrayList.get(arg0);
}
@Override
public int getCount() {
return arrayList.size();
}
}
