ViewPager+View实现Tab

注：源码来自慕课网。

使用ViewPager+View实现Tab底部导航：

主要思想：顶部top.xml，中间ViewPager，底部线性布局Tab导航。

top.xml具体实现：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="45dp"
android:background="@drawable/title_bar"
android:gravity="center"
android:orientation="vertical" >

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="微信"
android:textColor="#ffffff"
android:textSize="20sp"
android:textStyle="bold" />

</LinearLayout>

底部导航的实现：1个线性布局里面包含4个线性布局，作为4个Tab。

bottom.xml底部导航：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="55dp"
android:background="@drawable/bottom_bar"
android:orientation="horizontal" >

<LinearLayout
android:id="@+id/id_tab_weixin"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:gravity="center"
android:orientation="vertical" >

<ImageButton
android:id="@+id/id_tab_weixin_img"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#00000000"
android:clickable="false"
android:src="@drawable/tab_weixin_pressed" />

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="微信"
android:textColor="#ffffff" />
</LinearLayout>

<LinearLayout
android:id="@+id/id_tab_frd"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:gravity="center"
android:orientation="vertical" >

<ImageButton
android:id="@+id/id_tab_frd_img"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#00000000"
android:clickable="false"
android:src="@drawable/tab_find_frd_normal" />

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="朋友"
android:textColor="#ffffff" />
</LinearLayout>

<LinearLayout
android:id="@+id/id_tab_address"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:gravity="center"
android:orientation="vertical" >

<ImageButton
android:id="@+id/id_tab_address_img"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#00000000"
android:clickable="false"
android:src="@drawable/tab_address_normal" />

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="通讯录"
android:textColor="#ffffff" />
</LinearLayout>

<LinearLayout
android:id="@+id/id_tab_settings"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:gravity="center"
android:orientation="vertical" >

<ImageButton
android:id="@+id/id_tab_settings_img"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#00000000"
android:clickable="false"
android:src="@drawable/tab_settings_normal" />

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="设置"
android:textColor="#ffffff" />
</LinearLayout>

</LinearLayout>

省略4个Tab的布局文件。

activity_main.xml实现方法：一个线性布局，包含top.xml和bottom.xml，中间用ViewPager，注意这里为了使ViewPager充满屏幕，同时不遮住底部导航，

这里必须设置ViewPager的高度：android:layout_height="0dp";android:layout_weight="1".

activity_main.xml具体实现：

<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" >

<include layout="@layout/top" />

<android.support.v4.view.ViewPager
android:id="@+id/id_viewpager"
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1" >
</android.support.v4.view.ViewPager>

<include layout="@layout/bottom" />

</LinearLayout>

到这里布局文件准备好了。接下来开始写MainActivity.java。比较简单，代码如下：

Activity.java具体实现：

package com.imooc.tab01;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.view.Window;
import android.widget.ImageButton;
import android.widget.LinearLayout;

public class MainActivity extends Activity implements OnClickListener
{

private ViewPager mViewPager;
private PagerAdapter mAdapter;
private List<View> mViews = new ArrayList<View>();
// TAB

private LinearLayout mTabWeixin;
private LinearLayout mTabFrd;
private LinearLayout mTabAddress;
private LinearLayout mTabSetting;

private ImageButton mWeixinImg;
private ImageButton mFrdImg;
private ImageButton mAddressImg;
private ImageButton mSettingImg;

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

initView();

initEvents();

}

private void initEvents()
{
mTabWeixin.setOnClickListener(this);
mTabFrd.setOnClickListener(this);
mTabAddress.setOnClickListener(this);
mTabSetting.setOnClickListener(this);

mViewPager.setOnPageChangeListener(new OnPageChangeListener()
{

@Override
public void onPageSelected(int arg0)
{
int currentItem = mViewPager.getCurrentItem();
resetImg();
switch (currentItem)
{
case 0:
mWeixinImg.setImageResource(R.drawable.tab_weixin_pressed);
break;
case 1:
mFrdImg.setImageResource(R.drawable.tab_find_frd_pressed);
break;
case 2:
mAddressImg
.setImageResource(R.drawable.tab_address_pressed);
break;
case 3:
mSettingImg
.setImageResource(R.drawable.tab_settings_pressed);
break;

}

}

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

}

@Override
public void onPageScrollStateChanged(int arg0)
{

}
});
}

private void initView()
{
mViewPager = (ViewPager) findViewById(R.id.id_viewpager);
// tabs
mTabWeixin = (LinearLayout) findViewById(R.id.id_tab_weixin);
mTabFrd = (LinearLayout) findViewById(R.id.id_tab_frd);
mTabAddress = (LinearLayout) findViewById(R.id.id_tab_address);
mTabSetting = (LinearLayout) findViewById(R.id.id_tab_settings);
// ImageButton
mWeixinImg = (ImageButton) findViewById(R.id.id_tab_weixin_img);
mFrdImg = (ImageButton) findViewById(R.id.id_tab_frd_img);
mAddressImg = (ImageButton) findViewById(R.id.id_tab_address_img);
mSettingImg = (ImageButton) findViewById(R.id.id_tab_settings_img);

LayoutInflater mInflater = LayoutInflater.from(this);
View tab01 = mInflater.inflate(R.layout.tab01, null);
View tab02 = mInflater.inflate(R.layout.tab02, null);
View tab03 = mInflater.inflate(R.layout.tab03, null);
View tab04 = mInflater.inflate(R.layout.tab04, null);
mViews.add(tab01);
mViews.add(tab02);
mViews.add(tab03);
mViews.add(tab04);

mAdapter = new PagerAdapter()
{

@Override
public void destroyItem(ViewGroup container, int position,
Object object)
{
container.removeView(mViews.get(position));
}

@Override
public Object instantiateItem(ViewGroup container, int position)
{
View view = mViews.get(position);
container.addView(view);
return view;
}

@Override
public boolean isViewFromObject(View arg0, Object arg1)
{
return arg0 == arg1;
}

@Override
public int getCount()
{
return mViews.size();
}
};

mViewPager.setAdapter(mAdapter);

}

@Override
public void onClick(View v)
{
resetImg();
switch (v.getId())
{
case R.id.id_tab_weixin:
mViewPager.setCurrentItem(0);
mWeixinImg.setImageResource(R.drawable.tab_weixin_pressed);
break;
case R.id.id_tab_frd:
mViewPager.setCurrentItem(1);
mFrdImg.setImageResource(R.drawable.tab_find_frd_pressed);
break;
case R.id.id_tab_address:
mViewPager.setCurrentItem(2);
mAddressImg.setImageResource(R.drawable.tab_address_pressed);
break;
case R.id.id_tab_settings:
mViewPager.setCurrentItem(3);
mSettingImg.setImageResource(R.drawable.tab_settings_pressed);
break;

default:
break;
}
}

/**
* 将所有的图片切换为暗色的
*/
private void resetImg()
{
mWeixinImg.setImageResource(R.drawable.tab_weixin_normal);
mFrdImg.setImageResource(R.drawable.tab_find_frd_normal);
mAddressImg.setImageResource(R.drawable.tab_address_normal);
mSettingImg.setImageResource(R.drawable.tab_settings_normal);
}

}