我有一个Viewpager,其中包含片段,每个片段只包含一个imageView。
这是我的适配器类:
public class customAdapter_ProfilePictureAdapter extends FragmentPagerAdapter {
Context context;
ArrayList<String> pictureList;
Bundle bundle;
int size;
String TAG="profileAdapter";
public customAdapter_ProfilePictureAdapter(Context c, FragmentManager fm, ArrayList<String> pictureList, int size) {
super(fm);
this.pictureList=pictureList;
this.size=size;
context=c;
}
@Override
public Fragment getItem(int position) {
fragment_act_1_3_profile_pictures pictureFragment = new fragment_act_1_3_profile_pictures();
bundle = new Bundle();
bundle.putString("picture", pictureList.get(position));
Log.d(TAG, "getItem: "+pictureList.get(position));
bundle.putInt("numPic", position);
pictureFragment.setArguments(bundle);
return pictureFragment;
}
@Override
public int getCount() {
return size;
}
@Override
public int getItemPosition(Object object) {
return POSITION_NONE;
}
}
pictureList最多包含三个URL。以下是获取URL的方法:
public void getProfilePic(final Context context, String url, final ImageView imageView, final ArrayList<String> pictureList, final ViewPager profilePictureViewPager, final TabLayout pictureTabLayout, final FragmentManager fm, final String kind, final int turn){
requestQueue= Volley.newRequestQueue(context);
pictureList.clear();
String userID = getUserId();
final JsonObjectRequest request= new JsonObjectRequest(Request.Method.GET, url,null, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
try {
String firstPictureUri= response.getJSONArray("records").getJSONObject(0).getString("firstPicture");
String secondPictureUri= response.getJSONArray("records").getJSONObject(0).getString("secondPicture");
String thirdPictureUri= response.getJSONArray("records").getJSONObject(0).getString("thirdPicture");
if(firstPictureUri.equals("n.a.")){
pictureList.add("android.resource://org.coerdt.kitebook/mipmap/default_pic");
}
else{
pictureList.add(firstPictureUri);
}
if(!secondPictureUri.equals("n.a.")){
pictureList.add(secondPictureUri);
}
if(!thirdPictureUri.equals("n.a.")){
pictureList.add(thirdPictureUri);
}
if(turn==0){
profilePictureAdapter = new customAdapter_ProfilePictureAdapter(context,fm ,pictureList,pictureList.size());
profilePictureViewPager.setAdapter(profilePictureAdapter);
pictureTabLayout.setupWithViewPager(profilePictureViewPager);
}
else{
profilePictureAdapter.notifyDataSetChanged();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
});
requestQueue.add(request);
}
“turn”变量指示Viewpager是在当前活动中第一次填充的(turn==0),还是刚刚更新的(turn==1)
当用户添加/替换URL时,Viewpager/片段不会得到更新。我也试过了
profilePictureViewPager.setAdapter(null);
何时应更新Viewpager。
我确信pictureList包含更新的URL。
我做错了什么?
