如何根据用户选择在ViewPager中设置CurrentPage &我怎么知道哪个列表项称为活动 [英] How to setCurrentPage in ViewPager according to user selection & how do I know which list item called the activity
问题描述
我是Android 编程的新手.
我有一个项目列表，当用户点击一个项目时，它会将他们带到一个包含该项目详细信息的屏幕.
I have a list of items, when the user clicks on an item it takes them to a screen with that item details.
我希望用户能够左右滑动以查看列表中其他项目的详细信息，而不是返回列表并选择另一个项目.
I want the user to have the ability to swipe right and left to view other items' details in the list, instead of going back to the list and choosing another item.
我读到我需要使用 ViewPager 来实现左右滑动，所以我这样做了.
ViewPager 工作正常，但是当我单击列表中的任何项目时，我总是会到达 ViewPager 中的第一页.
I read that I need to use ViewPager for the ability to swipe right and left, so I did that.
ViewPager works fine, but my problem when I click any item on the list I always get to the first page in the ViewPager.
我不希望这样，我想要的是，如果我单击列表中的第 4 项，它会将我带到查看寻呼机中的第 4 页，并且仍然能够左右滑动以查看其他项目的详细信息.
我知道如何通过 使用 mPager.setCurrentItem(0)
在 viewpager 中设置页面但我不知道如何根据从列表中选择的项目(即启动活动的项目)进行设置.
I don't want that, what I want is if I click on item 4 on the list it takes me to page 4 in the view pager and still have the ability to swipe right and left to view the details of other items.
I know how to set the page in viewpager by using mPager.setCurrentItem(0)
But I don't know how to set it according to which item was selected from the list (i.e which item launched the activity).
这是我的代码:
包含列表视图的主要活动:
Main activity which contains the listview:
public class Main extends SherlockListActivity implements OnItemClickListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ListView mylist = (ListView) findViewById(android.R.id.list);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.simple_list_reda_1, R.id.list_content, getResources().getStringArray(R.array.items_list_array) );
mylist.setAdapter(adapter);
mylist.setOnItemClickListener(new OnItemClickListener()
{
public void onItemClick(AdapterView<?> arg0,View arg1, int position, long arg3)
{
Intent n = null;
switch (position){
case 0:
n = new Intent(getApplicationContext(), ViewPagerClass.class);
break;
case 1:
n = new Intent(getApplicationContext(), ViewPagerClass.class);
break;
case 2:
n = new Intent(getApplicationContext(), ViewPagerClass.class);
break;
case 3:
n = new Intent(getApplicationContext(), ViewPagerClass.class);
break;
}
if(null!=n)
startActivity(n);
}
});
}
}
ViewPagerClass
ViewPagerClass
public class ViewPagerClass extends SherlockFragmentActivity{
static final int NUM_ITEMS = 4;
MyAdapter mAdapter;
ViewPager mPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
super.setContentView(R.layout.viewpager_layout);
mAdapter = new MyAdapter(getSupportFragmentManager());
mPager = (ViewPager) findViewById(R.id.viewpager);
mPager.setAdapter(mAdapter);
//mPager.setCurrentItem(2);
final ActionBar ab = getSupportActionBar();
ab.setDisplayHomeAsUpEnabled(true);
ab.setDisplayUseLogoEnabled(false);
ab.setDisplayShowHomeEnabled(false);
}
public static class MyAdapter extends FragmentPagerAdapter {
public MyAdapter(FragmentManager fm) {
super(fm);
}
@Override
public int getCount() {
return NUM_ITEMS;
}
@Override
public Fragment getItem(int position) {
switch(position){
case 0: return FirstPageFragment.newInstance();
case 1: return SecondPageFragment.newInstance();
case 2: return ThirdPageFragment.newInstance();
case 3: return FourthPageFragment.newInstance();
}
return null;
}
}
public static class FirstPageFragment extends Fragment {
public static FirstPageFragment newInstance() {
FirstPageFragment f = new FirstPageFragment();
return f;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View V = inflater.inflate(R.layout.fragment1, container, false);
return V;
}
}
public static class SecondPageFragment extends Fragment {
public static SecondPageFragment newInstance() {
SecondPageFragment f = new SecondPageFragment();
return f;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View V = inflater.inflate(R.layout.fragment2, container, false);
return V;
}
}
public static class ThirdPageFragment extends Fragment {
public static ThirdPageFragment newInstance() {
ThirdPageFragment f = new ThirdPageFragment();
return f;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View V = inflater.inflate(R.layout.fragment3, container, false);
return V;
}
}
public static class FourthPageFragment extends Fragment {
public static ThirdPageFragment newInstance() {
ThirdPageFragment f = new ThirdPageFragment();
return f;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View V = inflater.inflate(R.layout.fragment4, container, false);
return V;
}
}
最后查看pager_layout.xml
Finally viewpager_layout.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
>
<android.support.v4.view.ViewPager
android:id="@+android:id/viewpager"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
简而言之，我想要的是:如果我点击列表中的第 3 项，我会进入显示第 3 项详细信息的屏幕，如果我向右滑动，我会看到第 4 项，如果我向左滑动，我会看到第 2 项.
So in short What I want is: If I click on item 3 in the list I go to screen with the details on item 3, and if I swipe to the right I get to item 4, and if I swipe to the left I get to item 2.
推荐答案
在 onItemClickListener() 中，您需要向 Intent 添加额外的内容，以便在该活动启动时获取它.
In the onItemClickListener() you need to add an extra to the intent so you can get it when that activity launches.
n.putExtra("POSITION_KEY", position);
在ViewPagerClass onCreate()中使用
int position = getIntent().getIntExtra("POSITION_KEY", 0);
mPager.setCurrentItem(position);
这应该做你想做的事.
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