Android如何知道您的标签何时获得关注,
我的活动中有一个选项卡视图 目前我正在片段Android如何知道您的标签何时获得关注,,android,android-fragments,android-actionbar,android-tabs,Android,Android Fragments,Android Actionbar,Android Tabs,我的活动中有一个选项卡视图 目前我正在片段onCreateView中进行UI更新,但我认为这不是正确的位置 是否有一个方法可以重载,当我的选项卡获得视图时将调用该方法?这样,当我的用户单击或滚动到我的选项卡时,我就可以轮询我的服务器并更新我的视图 一些简化代码: @SuppressLint("NewApi") public class Rhino68PanelActivity extends FragmentActivity implements ActionBar.TabListener {
onCreateView
中进行UI更新,但我认为这不是正确的位置
是否有一个方法可以重载,当我的选项卡获得视图时将调用该方法?这样,当我的用户单击或滚动到我的选项卡时,我就可以轮询我的服务器并更新我的视图
一些简化代码:
@SuppressLint("NewApi")
public class Rhino68PanelActivity extends FragmentActivity implements ActionBar.TabListener {
static String TAG = "Rhino68PanelActivty";
/**
* The {@link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {@link android.support.v4.app.FragmentPagerAdapter} derivative, which
* will keep every loaded fragment in memory. If this becomes too memory
* intensive, it may be best to switch to a
* {@link android.support.v4.app.FragmentStatePagerAdapter}.
*/
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {@link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_rhino68_panel);
// Set up the action bar.
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Create the adapter that will return a fragment for each of the three
// primary sections of the app.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
// When swiping between different sections, select the corresponding
// tab. We can also use ActionBar.Tab#select() to do this if we have
// a reference to the Tab.
mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
// For each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by
// the adapter. Also specify this Activity object, which implements
// the TabListener interface, as the callback (listener) for when
// this tab is selected.
actionBar.addTab(actionBar.newTab().setText(mSectionsPagerAdapter.getPageTitle(i)).setTabListener(this));
}
}
@Override
protected void onDestroy() {
super.onDestroy();
Network.cancelRequests(Rhino68PanelActivity.this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.rhino68_panel, menu);
return true;
}
@Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
// When the given tab is selected, switch to the corresponding page in
// the ViewPager.
mViewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
@Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
/**
* A {@link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
Fragment fragment = null;
switch (position) {
case 0: {
fragment = new OneSectionFragment();
}
break;
case 1: {
fragment = new TwoSectionFragment();
}
break;
case 2: {
fragment = new ThreeSectionFragment();
}
break;
default: {
fragment = new OneSectionFragment();
}
}
return fragment;
}
@Override
public int getCount() {
// Show 3 total pages.
return 3;
}
@Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return "1";
case 1:
"2";
case 2:
"3";
}
return null;
}
}
public static class oneSectionFragment extends Fragment {
private static Context mContext;
public StatusSectionFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_rhino68_panel_status, container, false);
mContext = getActivity();
// update view
....
return rootView;
}
//fucntions and methods
}
public static class twoSectionFragment extends Fragment {
private static Context mContext;
public StatusSectionFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_rhino68_panel_status, container, false);
mContext = getActivity();
// update view
....
return rootView;
}
//fucntions and methods
}
@SuppressLint(“NewApi”)
公共类活动扩展FragmentActivity实现ActionBar.TabListener{
静态字符串TAG=“Rhino68PanelActivty”;
/**
*将提供的{@link android.support.v4.view.PagerAdapter}
*每个部分的片段。我们使用
*{@link android.support.v4.app.FragmentPagerAdapter}派生,其中
*将所有加载的片段保留在内存中。如果这变得太内存化
*密集型,最好换成
*{@link android.support.v4.app.FragmentStatePagerAdapter}。
*/
分段SPAGERADAPTER mSectionsPagerAdapter;
/**
*将承载节内容的{@link ViewPager}。
*/
ViewPager mViewPager;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity\u面板);
//设置操作栏。
最终ActionBar ActionBar=getActionBar();
actionBar.setNavigationMode(actionBar.NAVIGATION\u MODE\u选项卡);
//创建适配器,该适配器将为这三个函数中的每一个返回一个片段
//应用程序的主要部分。
mSectionsPagerAdapter=newsectionspageradapter(getSupportFragmentManager());
//使用分区适配器设置ViewPager。
mViewPager=(ViewPager)findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
//在不同区段之间滑动时,选择相应的
//我们也可以使用ActionBar.tab#select()来完成这项工作
//对选项卡的引用。
mViewPager.setOnPageChangeListener(新的ViewPager.SimpleOnPageChangeListener(){
@凌驾
已选择页面上的公共无效(内部位置){
actionBar.setSelectedNavigationItem(位置);
}
});
//对于应用程序中的每个部分,在操作栏中添加一个选项卡。
对于(int i=0;i
您可以使用以下方法更新每个SectionFragment中的视图:
@Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if (isVisibleToUser) { }
else { }
}
@请参阅:问题1:知道哪个选项卡有焦点 解决方案:在ViewPager上设置setOnPageChangeListener。通过收到的索引,您知道哪个选项卡处于活动状态 问题2:如何从活动数据库执行方法