在我的MainActivity中我有一个列表，当一个项目被点击时，我进入我的ScreenSlideActivity。这个活动将从我称为ScreenSlidePageFragment的另一个类中产生一个Fragment，并在我滑动时为我产生一些Fragment。我需要这些片段的内容是唯一的，这取决于我选择的列表中的任何项目。不幸的是，我在这方面没有成功。
我试过在ScreenSlidePageFragment内部创建一个set_all_data(string_data){}函数，并在我创建Fragment之前调用它/更新textView，但我认为我要么得到新的文本的竞争条件，要么我只是做错了，不理解Fragment不够好。
ScreenSlideActivity
package com.example.dgzl.corvegas;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.app.NavUtils;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
import org.w3c.dom.Text;
/**
* Demonstrates a "screen-slide" animation using a {@link ViewPager}. Because {@link ViewPager}
* automatically plays such an animation when calling {@link ViewPager#setCurrentItem(int)}, there
* isn't any animation-specific code in this sample.
*
* <p>This sample shows a "next" button that advances the user to the next step in a wizard,
* animating the current screen out (to the left) and the next screen in (from the right). The
* reverse animation is played when the user presses the "previous" button.</p>
*
* @see ScreenSlidePageFragment
*/
public class ScreenSlideActivity extends android.support.v4.app.FragmentActivity {
/* The number of pages (wizard steps) to show in this demo.*/
private static final int NUM_PAGES = 3;
/* The pager widget, which handles animation and allows swiping horizontally to access previous
* and next wizard steps.*/
private ViewPager mPager;
/* The pager adapter, which provides the pages to the view pager widget.*/
private PagerAdapter mPagerAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_screen_slide);
// getting intent data
Intent in = getIntent();
// Get JSON values from previous intent
final String biz_data[] = in.getStringArrayExtra("biz_data");
set_fragment_data(biz_data);
// Instantiate a ViewPager and a PagerAdapter.
mPager = (ViewPager) findViewById(R.id.pager);
mPagerAdapter = new ScreenSlidePagerAdapter(getSupportFragmentManager());
mPager.setAdapter(mPagerAdapter);
mPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageSelected(int position) {
invalidateOptionsMenu();
}
});
}
public void onFragClick (View view){
Toast.makeText(ScreenSlideActivity.this, "button", Toast.LENGTH_SHORT).show();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
getMenuInflater().inflate(R.menu.activity_screen_slide, menu);
// enable 'prev' and 'next' when not on first node
menu.findItem(R.id.action_prev).setEnabled(mPager.getCurrentItem() > 0);
menu.findItem(R.id.action_next).setEnabled(mPager.getCurrentItem() < (NUM_PAGES-1));
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case 16908332:
// Navigate "up" the demo structure to the launchpad activity.
// See http://developer.android.com/design/patterns/navigation.html for more.
finish();
return true;
case R.id.action_prev:
// Go to the previous step in the wizard. If there is no previous step,
// setCurrentItem will do nothing.
mPager.setCurrentItem(mPager.getCurrentItem() - 1);
return true;
case R.id.action_next:
// Advance to the next step in the wizard. If there is no next step, setCurrentItem
// will do nothing.
mPager.setCurrentItem(mPager.getCurrentItem() + 1);
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A simple pager adapter that represents 5 {@link ScreenSlidePageFragment} objects, in
* sequence.
*/
private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {
public ScreenSlidePagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
String test_data = "Soem data";
ScreenSlidePageFragment newFrag = new ScreenSlidePageFragment();
newFrag.set_all_data(test_data);
Fragment newFragment = newFrag.create(position);
return newFragment;
}
@Override
public int getCount() {
return NUM_PAGES;
}
}
public void set_fragment_data(String biz_data[]){
// title as business name
setTitle(biz_data[1]);
}
}
ScreenSlidePageFragment
package com.example.dgzl.corvegas;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
/**
* A fragment representing a single step in a wizard. The fragment shows a dummy title indicating
* the page number, along with some dummy text.
*
* <p>This class is used by the {@link } and {@link
* ScreenSlideActivity} samples.</p>
*/
public class ScreenSlidePageFragment extends android.support.v4.app.Fragment {
/**
* The argument key for the page number this fragment represents.
*/
public static final String ARG_PAGE = "page";
/**
* The fragment's page number, which is set to the argument value for {@link #ARG_PAGE}.
*/
private int mPageNumber;
public String[] todays_data, biz_data, special_data;
public String all_data = "hardcoded and not good";
/**
* Factory method for this fragment class. Constructs a new fragment for the given page number.
*/
public static ScreenSlidePageFragment create(int pageNumber) {
ScreenSlidePageFragment fragment = new ScreenSlidePageFragment();
Bundle args = new Bundle();
args.putInt(ARG_PAGE, pageNumber);
fragment.setArguments(args);
Log.d("OnCreateView: ", "2");
return fragment;
}
public ScreenSlidePageFragment() {
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mPageNumber = getArguments().getInt(ARG_PAGE);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
ViewGroup rootView;
Log.d("OnCreateView: ", "1");
TextView tv;
switch(getPageNumber()){
case 0:
rootView = (ViewGroup) inflater.inflate(R.layout.fragment_today, container, false);
tv = (TextView)rootView.findViewById(R.id.today_frag_tv);
tv.setText(R.string.today_frag);
break;
case 1:
rootView = (ViewGroup) inflater.inflate(R.layout.fragment_business, container, false);
tv = (TextView)rootView.findViewById(R.id.biz_frag_tv);
tv.setText(all_data);
break;
case 2:
rootView = (ViewGroup) inflater.inflate(R.layout.fragment_specials, container, false);
tv = (TextView)rootView.findViewById(R.id.specials_frag_tv);
tv.setText(R.string.special_frag);
break;
default:
rootView = (ViewGroup) inflater.inflate(R.layout.fragment_today, container, false);
tv = (TextView)rootView.findViewById(R.id.today_frag_tv);
tv.setText(R.string.today_frag);
}
// Set the title view to show the page number.
// ((TextView) rootView.findViewById(android.R.id.text1)).setText(getString(R.string.title_template_step, mPageNumber + 1));
return rootView;
}
/**
* Returns the page number represented by this fragment object.
*/
public int getPageNumber() {
return mPageNumber;
}
public void set_data(String[] todays_data, String[] biz_data, String[] special_data) {
this.todays_data = todays_data;
this.biz_data = biz_data;
this.special_data = special_data;
}
public void set_all_data(String all_data) {
this.all_data = all_data;
}
public void get_data() {
}
}
问题在getItem()方法。你正在创建一个new ScreenSlidePageFragment，之后，你调用create()方法，再次创建一个new ScreenSlidePageFragment。您需要以静态方式调用ScreenSlidePageFragment.create(position)。
@Override
public Fragment getItem(int position) {
String test_data = "Soem data";
ScreenSlidePageFragment newFrag = ScreenSlidePageFragment.create(position);
newFrag.set_all_data(test_data);
return newFragment;
}