我正在尝试使用 ViewPager
和 4 Fragments
通过滑动来实现 Tab
。当我滑动选项卡时, fragment 网络各自的 xml 布局
在每个选项卡上正确显示,但 fragment 的代码未正确执行。
例如-以下选项卡中包含相应的 fragment 。
Tab0-ButtonFragment
public class ButtonFragment extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_button, container, false);
Log.i("inside", "button fragment");
return rootView;
}
Tab1-ImageFragment
public class ImageFragment extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_image, container, false);
Log.i("inside", "image fragment");
return rootView;
}
Tab2-TextFragment
public class TextFragment extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_text, container, false);
Log.i("inside", "text fragment");
return rootView;
}
Tab3-测试 公共(public)类测试扩展 fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.temp, container, false);
Log.i("inside", "tessssssssst fragment");
return rootView;
}
当显示选项卡时 我同时收到 tab0 和 tab1 的日志消息。然后在滑动并转到 tab1 后,我收到 tab2 的日志消息。滑动到选项卡 2 后,我收到选项卡 3 的日志消息,到达选项卡 3 时,不会显示任何日志消息。谁能告诉我如何执行各个选项卡的相应代码?我的剩余代码如下:
public class TabsPagerAdapter extends FragmentPagerAdapter { //Update - code formatting
public TabsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem( int index) {
Log.i("index", "" + index);
switch (index) {
case 0:
// Top Rated fragment activity
return new ButtonFragment();
case 1:
// Games fragment activity
return new ImageFragment();
case 2:
// Movies fragment activity
return new TextFragment();
case 3:
return new Test();
}
return null;
}
@Override
public int getCount() {
// get item count - equal to number of tabs
return 4;
}
主要 Activity
public class MainActivity extends FragmentActivity implements OnTabChangeListener, OnPageChangeListener {
private TabsPagerAdapter mAdapter;
private ViewPager mViewPager;
private TabHost mTabHost;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mViewPager = (ViewPager) findViewById(R.id.viewpager);
// Tab Initialization
initialiseTabHost();
mAdapter = new TabsPagerAdapter(getSupportFragmentManager());
// Fragments and ViewPager Initialization
mViewPager.setAdapter(mAdapter);
mViewPager.setOnPageChangeListener(MainActivity.this);
}
// Method to add a TabHost
private static void AddTab(MainActivity activity, TabHost tabHost, TabHost.TabSpec tabSpec) {
tabSpec.setContent(new MyTabFactory(activity));
tabHost.addTab(tabSpec);
}
// Manages the Tab changes, synchronizing it with Pages
public void onTabChanged(String tag) {
int pos = this.mTabHost.getCurrentTab();
this.mViewPager.setCurrentItem(pos);
}
@Override
public void onPageScrollStateChanged(int arg0) {
}
// Manages the Page changes, synchronizing it with Tabs
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
int pos = this.mViewPager.getCurrentItem();
this.mTabHost.setCurrentTab(pos);
}
@Override
public void onPageSelected(int arg0) {
}
// Tabs Creation
private void initialiseTabHost() {
mTabHost = (TabHost) findViewById(android.R.id.tabhost);
mTabHost.setup();
// TODO Put here your Tabs
MainActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("ButtonTab").setIndicator("ButtonTab"));
MainActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("ImageTab").setIndicator("ImageTab"));
MainActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("TextTab").setIndicator("TextTab"));
MainActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("TestingTab").setIndicator("TestingTab"));
mTabHost.setOnTabChangedListener(this);
}
最佳答案
这是 viewpager 的默认行为,您无法更改它,因为 viewpager 创建 fragment 以便 View 存在,以便用户可以在它们之间滑动,以便旧 View 滑出屏幕,新 View 滑到屏幕上。你可以像这样编写代码
@Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if (isVisibleToUser) {
Log.i("inside", "button fragment");
}else{
// fragment is not visible
}
}
这样当 fragment 可见时您的代码就会执行
关于android - 选项卡执行 Android 中下一个 fragment 中存在的代码,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/35594132/