FragmentStatePagerAdapter returns getItem 中的错误位置
FragmentStatePagerAdapter returns wrong positions in getItem
我正在使用 FragmentStatePagerAdapter
。 getItem(int position)
returns 错误的位置。我有5个片段。这是我更改片段时的位置:
Fragment0 -> Fragment1: position = 2
Fragment1 -> Fragment2: position = 3
Fragment2 -> Fragment3: position = 4
Fragment3 -> Fragment4: getItem is not called!
Fragment4 -> Fragment3: position = 2
Fragment3 -> Fragment2: position = 1
Fragment2 -> Fragment1: position = 0
Fragment1 -> Fragment0: getItem is not called!
这是我的适配器的代码:
import android.content.Context;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
public class AppFragmentPageAdapter extends FragmentStatePagerAdapter {
final int PAGE_COUNT = 5;
private String tabTitles[] = new String[] { "اخبار", "حقیقتسنج", "ویدیوها", "زندگینامه", "برنامهها" };
private Context context;
public AppFragmentPageAdapter(FragmentManager fm, Context context) {
super(fm);
this.context = context;
}
@Override
public int getCount() {
return PAGE_COUNT;
}
@Override
public Fragment getItem(int position) {
switch (position) {
case (0):
return NewsFragment.newInstance(position);
default:
return VideosFragment.newInstance(position);
}
}
@Override
public CharSequence getPageTitle(int position) {
return tabTitles[position];
}
}
这是正常行为。默认情况下,FragmentStatePagerAdapter 为当前显示的片段及其邻居保留 link。首先适配器创建 Fragment0 和 Fragment1。当您滑动到 Fragment1 时,他将创建 Fragment2 并为此调用 getItem(2)。滑动到 Fragment2 后,adapter 会销毁 Fragment0 并创建 Fragment3。
我正在使用 FragmentStatePagerAdapter
。 getItem(int position)
returns 错误的位置。我有5个片段。这是我更改片段时的位置:
Fragment0 -> Fragment1: position = 2
Fragment1 -> Fragment2: position = 3
Fragment2 -> Fragment3: position = 4
Fragment3 -> Fragment4: getItem is not called!
Fragment4 -> Fragment3: position = 2
Fragment3 -> Fragment2: position = 1
Fragment2 -> Fragment1: position = 0
Fragment1 -> Fragment0: getItem is not called!
这是我的适配器的代码:
import android.content.Context;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
public class AppFragmentPageAdapter extends FragmentStatePagerAdapter {
final int PAGE_COUNT = 5;
private String tabTitles[] = new String[] { "اخبار", "حقیقتسنج", "ویدیوها", "زندگینامه", "برنامهها" };
private Context context;
public AppFragmentPageAdapter(FragmentManager fm, Context context) {
super(fm);
this.context = context;
}
@Override
public int getCount() {
return PAGE_COUNT;
}
@Override
public Fragment getItem(int position) {
switch (position) {
case (0):
return NewsFragment.newInstance(position);
default:
return VideosFragment.newInstance(position);
}
}
@Override
public CharSequence getPageTitle(int position) {
return tabTitles[position];
}
}
这是正常行为。默认情况下,FragmentStatePagerAdapter 为当前显示的片段及其邻居保留 link。首先适配器创建 Fragment0 和 Fragment1。当您滑动到 Fragment1 时,他将创建 Fragment2 并为此调用 getItem(2)。滑动到 Fragment2 后,adapter 会销毁 Fragment0 并创建 Fragment3。