Java 通过片段显示活动时出错
我试图显示一个我的网页碎片,但它给我一个错误 我创建了一个名为FragmentContacts.java的单独类文件,从中我展示了activity_contacts.xml的布局 Java代码片段:Java 通过片段显示活动时出错,java,android,Java,Android,我试图显示一个我的网页碎片,但它给我一个错误 我创建了一个名为FragmentContacts.java的单独类文件,从中我展示了activity_contacts.xml的布局 Java代码片段: package me.example.app; import android.os.Bundle; import android.support.v4.app.FragmentActivity; import android.view.LayoutInflater; import android.
package me.example.app;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class FragmentContacts extends FragmentActivity {
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Get the view from fragmenttab1.xml
View view = inflater.inflate(R.layout.activity_contacts, container, false);
return view;
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
// setUserVisibleHint(true);
}
}
片段代码:
public Fragment getItem(int arg0) {
// getItem is called to instantiate the fragment for the given page.
// Return a DummySectionFragment (defined as a static inner class
// below) with the page number as its lone argument.
//Fragment fragment = new DummySectionFragment();
//Bundle args = new Bundle();
//args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
//fragment.setArguments(args);
//return fragment;
switch (arg0) {
// Open FragmentTab1.java Error on return fragmenttab1
case 0:
FragmentContacts fragmenttab1 = new FragmentContacts();
return fragmenttab1;
return null;
}
决心
这就是我所做的:
1) 我为每个选项卡分别创建了片段类。
2) 然后我使用了这个案例,以便在各自的选项卡中显示每个活动
(很抱歉我没有专业术语。)
解决方案:
package me.example.app;
import java.util.Locale;
import android.app.ActionBar;
import android.app.FragmentTransaction;
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.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class HomeActivity extends FragmentActivity implements
ActionBar.TabListener {
/**
* 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_home);
// 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 four
// 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
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.home, 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 arg0) {
// getItem is called to instantiate the fragment for the given page.
// Return a DummySectionFragment (defined as a static inner class
// below) with the page number as its lone argument.
switch (arg0){
case 0:
Fragment fragmentContacts = new FragmentContacts();
return fragmentContacts;
case 1:
Fragment fragmentMissed = new FragmentMissed();
return fragmentMissed;
case 2:
Fragment fragmentRecent = new FragmentRecent();
return fragmentRecent;
case 3:
Fragment fragmentGroups = new FragmentGroups();
return fragmentGroups;
}
return null;
}
@Override
public int getCount() {
// Show 4 total pages.
return 4;
}
@Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_section1).toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
case 3:
return getString(R.string.title_section4).toUpperCase(l);
}
return null;
}
}
/**Contacts*/
public static class FragmentContacts extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public FragmentContacts() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.activity_contacts,
container, false);
return rootView;
}
}
/**Missed Call*/
public static class FragmentMissed extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public FragmentMissed() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.activity_missed,
container, false);
return rootView;
}
}
/**Recent Call*/
public static class FragmentRecent extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public FragmentRecent() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.activity_recent,
container, false);
return rootView;
}
}
/**Groups*/
public static class FragmentGroups extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public FragmentGroups() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.activity_group,
container, false);
return rootView;
}
}
}
package me.example.app;
导入java.util.Locale;
导入android.app.ActionBar;
导入android.app.FragmentTransaction;
导入android.os.Bundle;
导入android.support.v4.app.Fragment;
导入android.support.v4.app.FragmentActivity;
导入android.support.v4.app.FragmentManager;
导入android.support.v4.app.FragmentPagerAdapter;
导入android.support.v4.view.ViewPager;
导入android.view.LayoutInflater;
导入android.view.Menu;
导入android.view.view;
导入android.view.ViewGroup;
导入android.widget.TextView;
公共类HomeActivity扩展了FragmentActivity实现
ActionBar.TabListener{
/**
*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_home);
//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,该适配器将为这四个函数中的每一个返回一个片段
//应用程序的主要部分。
mSectionsPagerAdapter=新节spageradapter(
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