Android利用Fragment实现Tab选项卡效果
利用Fragment实现Tab选项卡效果：
将RadioGroup与Fragment集合，实现tab选项卡效果，这里面最关键的几个文件：
1.FragmentTabAdapter类：
/**
*@Description:
*@Author:NateRobinson
*@Since:2015-2-12
*/
publicclassFragmentTabAdapterimplementsRadioGroup.OnCheckedChangeListener
{
privateList<Fragment>fragments;//一个tab页面对应一个Fragment
privateRadioGrouprgs;//用于切换tab
privateActivityactivity;//Fragment所属的Activity
privateintfragmentContentId;//Activity中所要被替换的区域的id
privateintcurrentTab;//当前Tab页面索引
privateOnRgsExtraCheckedChangedListeneronRgsExtraCheckedChangedListener;//用于让调用者在切换tab时候增加新的功能
publicFragmentTabAdapter(Activityactivity,List<Fragment>fragments,intfragmentContentId,RadioGrouprgs)
{
this.fragments=fragments;
this.rgs=rgs;
this.activity=activity;
this.fragmentContentId=fragmentContentId;
//默认显示第一页
android.app.FragmentTransactionft=activity.getFragmentManager().beginTransaction();
ft.add(fragmentContentId,fragments.get(0));
ft.commit();
rgs.setOnCheckedChangeListener(this);
}
@Override
publicvoidonCheckedChanged(RadioGroupradioGroup,intcheckedId)
{
for(inti=0;i<rgs.getChildCount();i++)
{
if(rgs.getChildAt(i).getId()==(checkedId))
{
Fragmentfragment=fragments.get(i);
FragmentTransactionft=activity.getFragmentManager().beginTransaction();
getCurrentFragment().onPause();//暂停当前tab
//getCurrentFragment().onStop();//暂停当前tab
if(fragment.isAdded())
{
//fragment.onStart();//启动目标tab的onStart()
fragment.onResume();//启动目标tab的onResume()
}
else
{
ft.add(fragmentContentId,fragment);
}
showTab(i);//显示目标tab
ft.commit();
//如果设置了切换tab额外功能功能接口
if(null!=onRgsExtraCheckedChangedListener)
{
onRgsExtraCheckedChangedListener.OnRgsExtraCheckedChanged(radioGroup,checkedId,i);
}
}
}
}
/**
*切换tab
*@paramidx
*/
privatevoidshowTab(intidx)
{
for(inti=0;i<fragments.size();i++)
{
Fragmentfragment=fragments.get(i);
FragmentTransactionft=activity.getFragmentManager().beginTransaction();
if(idx==i)
{
ft.show(fragment);
}
else
{
ft.hide(fragment);
}
ft.commit();
}
currentTab=idx;//更新目标tab为当前tab
}
publicintgetCurrentTab()
{
returncurrentTab;
}
publicFragmentgetCurrentFragment()
{
returnfragments.get(currentTab);
}
publicOnRgsExtraCheckedChangedListenergetOnRgsExtraCheckedChangedListener()
{
returnonRgsExtraCheckedChangedListener;
}
publicvoidsetOnRgsExtraCheckedChangedListener(OnRgsExtraCheckedChangedListeneronRgsExtraCheckedChangedListener)
{
this.onRgsExtraCheckedChangedListener=onRgsExtraCheckedChangedListener;
}
/**
*切换tab额外功能功能接口
*/
publicinterfaceOnRgsExtraCheckedChangedListener
{
voidOnRgsExtraCheckedChanged(RadioGroupradioGroup,intcheckedId,intindex);
}
}
2.activity_main.xml布局文件：
<?xmlversion="1.0"encoding="UTF-8"?> <LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:background="@android:color/white" android:orientation="vertical"> <LinearLayout android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical"> <FrameLayout android:id="@+id/tab_content" android:layout_width="fill_parent" android:layout_height="0dp" android:layout_weight="1.0" android:background="#77557799"/> <RadioGroup android:id="@+id/tabs_rg" android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="center" android:orientation="horizontal" android:paddingBottom="7dp" android:paddingTop="7dp"> <RadioButton android:id="@+id/tab_rb_a" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1.0" android:background="@drawable/selector_tab" android:button="@null" android:checked="true" android:drawableTop="@drawable/tablatestalert" android:gravity="center" android:singleLine="true" android:text="Tab1" android:textColor="#000000" android:textSize="13sp"/> <RadioButton android:id="@+id/tab_rb_b" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1.0" android:background="@drawable/selector_tab" android:button="@null" android:drawableTop="@drawable/tabsearch" android:gravity="center" android:singleLine="true" android:text="Tab2" android:textColor="#000000" android:textSize="13sp"/> <RadioButton android:id="@+id/tab_rb_c" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1.0" android:background="@drawable/selector_tab" android:button="@null" android:drawableTop="@drawable/tabrecommd" android:gravity="center" android:singleLine="true" android:text="Tab3" android:textColor="#000000" android:textSize="13sp"/> </RadioGroup> </LinearLayout> </LinearLayout>
3.MainActivity类：
/**
*@Description:
*@Author:NateRobinson
*@Since:2015-2-12
*/
publicclassMainActivityextendsActivity
{
privateRadioGrouprgs;
privateList<Fragment>fragments=newArrayList<Fragment>();
privateintindex;
privatestaticBooleanisExit=false;
privatestaticBooleanhasTask=false;
privateRadioButtonbutton;
privateTimertExit=newTimer();
privateTimerTasktask=newTimerTask()
{
@Override
publicvoidrun()
{
isExit=false;
hasTask=true;
}
};
privateFragmentTabAdaptertabAdapter;
@Override
publicvoidonCreate(BundlesavedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
fragments.add(newFragmentOne());
fragments.add(newFragmentTwo());
fragments.add(newFragmentThree());
rgs=(RadioGroup)findViewById(R.id.tabs_rg);
button=(RadioButton)findViewById(R.id.tab_rb_a);
tabAdapter=newFragmentTabAdapter(this,fragments,R.id.tab_content,rgs);
tabAdapter.setOnRgsExtraCheckedChangedListener(newFragmentTabAdapter.OnRgsExtraCheckedChangedListener()
{
@Override
publicvoidOnRgsExtraCheckedChanged(RadioGroupradioGroup,intcheckedId,intindex)
{
//利用这个index可以实现，如果不是在主页，按第一遍让它先跳转到第一个Fragment
System.out.println("Extra----"+index+"checked!!!");
MainActivity.this.index=index;
}
});
}
@Override
publicbooleanonKeyDown(intkeyCode,KeyEventevent)
{
if(keyCode==KeyEvent.KEYCODE_BACK)
{
if(index==0)
{
if(isExit==false)
{
isExit=true;
Toast.makeText(MainActivity.this,"再按一次退出程序",Toast.LENGTH_SHORT).show();
if(!hasTask)
{
tExit.schedule(task,1000);
}
}
else
{
finish();
System.exit(0);
}
}
else
{
//如果不是在主页，按第一遍让它先跳转到第一个Fragment
//利用上面的check方法会导致onCheckedChanged方法被执行多次
//rgs.check(button.getId());
button.setChecked(true);
}
}
returnfalse;
}
}
为了能同时学习Fragment生命周期，我在Fragment每个生命周期方法中加入了log打印，一个有三个这样的Fragment，我只贴出其中一个代码，其余和这个一样：
/**
*@Description:
*@Author:NateRobinson
*@Since:2015-2-12
*/
publicclassFragmentOneextendsBaseFragment
{
privateViewview;
@Override
publicvoidonAttach(Activityactivity)
{
super.onAttach(activity);
Log.d(TAG,"1==>FragmentOne=>onAttach");
}
@Override
publicvoidonCreate(BundlesavedInstanceState)
{
Log.d(TAG,"2==>FragmentOne==>onCreate");
super.onCreate(savedInstanceState);
}
@Override
publicViewonCreateView(LayoutInflaterinflater,ViewGroupcontainer,BundlesavedInstanceState)
{
Log.d(TAG,"3==>FragmentOne==>onCreateView");
view=inflater.inflate(R.layout.fragment1,container,false);
TextViewtv=(TextView)view.findViewById(R.id.tv);
tv.setText("FragmentOne");
returnview;
}
@Override
publicvoidonActivityCreated(BundlesavedInstanceState)
{
Log.d(TAG,"4==>FragmentOne==>onActivityCreated");
super.onActivityCreated(savedInstanceState);
}
@Override
publicvoidonStart()
{
Log.d(TAG,"5==>FragmentOne==>onStart");
super.onStart();
}
@Override
publicvoidonResume()
{
Log.d(TAG,"6==>FragmentOne==>onResume");
super.onResume();
}
@Override
publicvoidonPause()
{
Log.d(TAG,"7==>FragmentOne==>onPause");
super.onPause();
}
@Override
publicvoidonStop()
{
Log.d(TAG,"8==>FragmentOne==>onStop");
super.onStop();
}
@Override
publicvoidonDestroyView()
{
Log.d(TAG,"9==>FragmentOne==>onDestroyView");
super.onDestroyView();
}
@Override
publicvoidonDestroy()
{
Log.d(TAG,"10==>FragmentOne==>onDestroy");
super.onDestroy();
}
@Override
publicvoidonDetach()
{
Log.d(TAG,"11==>FragmentOne==>onDetach");
super.onDetach();
}
@Override
publicvoidonViewCreated(Viewview,BundlesavedInstanceState)
{
Log.d(TAG,"FragmentOne==>onViewCreated");
super.onViewCreated(view,savedInstanceState);
}
}
在编写过程中，我为了实现如果不是在主页，按第一遍让它先跳转到第一个Fragment这个效果，一开始使用了rgs.check(button.getId());这个方法，结果发现，这样的话onCheckedChanged监听事件会执行两次，后来改为button.setChecked(true);这个方法之后，成功解决了这个问题。
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持毛票票。