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之前用JakeWharton的开源框架ActionBarSherlock和ViewPager实现了对网易新闻客户端Tab标签的功能,ActionBarSherlock是在3.0以下的机器支持ActionBar的功能,有兴趣的可以看看开源框架ActionBarSherlock 和 ViewPager 仿网易新闻客户端,今天用到的是JakeWharton的另一开源控件ViewPageIndicator,ViewPager想必大家都知道,Indicator指示器的意思,所以ViewPageIndicator就是ViewPager指示器咯,什么是ViewPager指示器呢?看了下面这副图你就明白了
你看明白了没?就是ViewPager的分页指示器,比如很多应用的指引界面,下面的小圆点,还有一些应用上面的Tab等等,ViewPageIndicator都能很好的实现,今天就继续带大家来实现网易新闻的Tab功能
- 我们先得去Github上面下载这个库,下载地址:https://github.com/JakeWharton/Android-ViewPagerIndicator,下载下来之后你可以运行例子,来看看我们需要什么样的效果,然后在此基础上改成我们自己想要的效果
sample是提供给我们的例子,library是库工程,我们需要将其作为我们自己项目的依赖库,我们新建一个Android工程,将library导入工程我就不介绍了,比较简单相信大家都会,不知道的可以看看我的这篇文章http://blog.youkuaiyun.com/xiaanming/article/details/9971721
注:如果你新建的项目libs目录下面有android-support-v4.jar,你要将其删除,因为ViewPageIndicator里面有这个库,我们项目中不允许两个android-support-v4.jar,不删除我们的项目不能编译的
- 下面我们来介绍主要代码的编写了,先看布局文件,上面一个TabPageIndicator,下面一个ViewPager,还是很简单的布局咯
- <</span>LinearLayout
-
xmlns:android="http://schemas.android.com/apk/res/android" -
android:orientation="vertical" -
android:layout_width="fill_parent" -
android:layout_height="fill_parent"> -
-
<</span>com.viewpagerindicator.TabPageIndicator -
android:id="@+id/indicator" -
android:background="@drawable/base_action_bar_bg" -
android:layout_height="wrap_content" -
android:layout_width="fill_parent" -
/> -
<</span>android.support.v4.view.ViewPager -
android:id="@+id/pager" -
android:layout_width="fill_parent" -
android:layout_height="0dp" -
android:layout_weight="1" -
/> -
- </</span>LinearLayout>
- package
com.example.viewpageindicator; -
- import
android.os.Bundle; - import
android.support.v4.app.Fragment; - import
android.support.v4.app.FragmentActivity; - import
android.support.v4.app.FragmentManager; - import
android.support.v4.app.FragmentPagerAdapter; - import
android.support.v4.view.ViewPager; - import
android.support.v4.view.ViewPager.OnPageChangeListener; - import
android.widget.Toast; -
- import
com.viewpagerindicator.TabPageIndicator; -
- public
class MainActivity extends FragmentActivity { -
-
private static final String[] TITLE = new String[] { "头条", "房产", "另一面", "女人", -
"财经", "数码", "情感", "科技" }; -
-
@Override -
protected void onCreate(Bundle savedInstanceState) { -
super.onCreate(savedInstanceState); -
setContentView(R.layout.activity_main); -
-
//ViewPager的adapter -
FragmentPagerAdapter adapter = new TabPageIndicatorAdapter(getSupportFragmentManage r()); -
ViewPager pager = (ViewPager)findViewById(R.id.pager); -
pager.setAdapter(adapter); -
-
//实例化TabPageIndicator然后设置ViewPager与之关联 -
TabPageIndicator indicator = (TabPageIndicator)findViewById(R.id.indicator); -
indicator.setViewPager(pager); -
-
//如果我们要对ViewPager设置监听,用indicator设置就行了 -
indicator.setOnPageChangeListener(new OnPageChangeListener() { -
-
@Override -
public void onPageSelected(int arg0) { -
Toast.makeText(getApplicationContext(), TITLE[arg0], Toast.LENGTH_SHORT).show(); -
} -
-
@Override -
public void onPageScrolled(int arg0, float arg1, int arg2) { -
-
} -
-
@Override -
public void onPageScrollStateChanged (int arg0) { -
-
} -
}); -
-
} -
-
-
-
class TabPageIndicatorAdapter extends FragmentPagerAdapter { -
public TabPageIndicatorAdapter(FragmentManager fm) { -
super(fm); -
} -
-
@Override -
public Fragment getItem(int position) { -
//新建一个Fragment来展示ViewPager item的内容,并传递参数 -
Fragment fragment = new ItemFragment(); -
Bundle args = new Bundle(); -
args.putString("arg", TITLE[position]); -
fragment.setArguments(args); -
-
return fragment; -
} -
-
@Override -
public CharSequence getPageTitle(int position) { -
return TITLE[position % TITLE.length]; -
} -
-
@Override -
public int getCount() { -
return TITLE.length; -
} -
} -
- }
-
ViewPager 的item,也就是Fragment,我这里只用了一个TextView来显示从MainActivity传递过来的Tab的标题,只是为了模拟平常我们 实际使用中,从Activity传递参数给Fragment,布局我就不贴了,代码也比较简单,直接看代码吧
- package
com.example.viewpageindicator; -
- import
android.os.Bundle; - import
android.support.v4.app.Fragment; - import
android.view.LayoutInflater; - import
android.view.View; - import
android.view.ViewGroup; - import
android.widget.TextView; -
-
- public
class ItemFragment extends Fragment { -
-
@Override -
public View onCreateView(LayoutInflater inflater, ViewGroup container, -
Bundle savedInstanceState) { -
-
View contextView = inflater.inflate(R.layout.fragment_item, container, false); -
TextView mTextView = (TextView) contextView.findViewById(R.id.textview); -
-
//获取Activity传递过来的参数 -
Bundle mBundle = getArguments(); -
String title = mBundle.getString("arg"); -
-
mTextView.setText(title); -
-
return contextView; -
} -
-
@Override -
public void onActivityCreated(Bundle savedInstanceState) { -
super.onActivityCreated(savedInstanceState); -
} -
- }
- <</span>style
name="StyledIndicators" parent="@android:style/Theme.Light"> -
<</span>item name="vpiTabPageIndicatorStyle ">@style/CustomTabPageIndicator</</span>item> - </</span>style>
-
- <</span>style
name="CustomTabPageIndicator" parent="Widget.TabPageIndicator"> -
<</span>item name="android:background">@drawable/tab_indicator</</span>item> -
<</span>item name="android:textAppearance">@style/CustomTabPageIndicator.Text</</span>item> -
<</span>item name="android:textSize">14sp</</span>item> -
<</span>item name="android:dividerPadding">8dp</</span>item> -
<</span>item name="android:showDividers">middle</</span>item> -
<</span>item name="android:paddingLeft">10dp</</span>item> -
<</span>item name="android:paddingRight">10dp</</span>item> -
<</span>item name="android:fadingEdge">horizontal</</span>item> -
<</span>item name="android:fadingEdgeLength">8dp</</span>item> - </</span>style>
-
- <</span>style
name="CustomTabPageIndicator.Text" parent="android:TextAppearance.Medium"> -
<</span>item name="android:typeface">monospace</</span>item> -
<</span>item name="android:textColor">@drawable/selector_tabtext</</span>item> - </</span>style>
总结
用ViewPageIndicator实现这样子的Tab标签很容易,而且ViewPageIndicator里面还有各种的指示器,相对于用ActionBarSherlock来实现,ViewPageIndicator更加灵活,而且修改ActionBarSherlock的样式比较复杂,如果你的项目中有用到ActionBarSherlock这个库,你可以使用来实现Tab分页,如果Tab上面还加导航条,ActionBarSherlock只能使用ActionBar来实现咯,而使用ViewPageIndicator我们可以更加灵活的使用自己的布局,我们我还是推荐使用ViewPageIndicator,这只是我的个人观点