[英]Delete a View from PagerAdapter in Android
我已經搜索了多個網站,android開發者網站,但碰巧遇到了麻煩,我不得不尋求社區的幫助。 所有幫助和建議將不勝感激。
問題 :
我總共從服務器收到12張圖像(在此處解析),並在PagerAdapter中顯示它們。 如果所有值都不都是null,則適配器代碼可以正常工作,但有一個缺點是我允許將null值存儲在服務器中。 當我從服務器取回整個列表時,我只想將那些視圖包含在不包含null的適配器中。 示例:假設我得到5個空路徑,然后我的適配器總共顯示12個視圖(其中7個帶有圖像,其余為空白頁)。
我的適配器代碼:
public class ProfileImageAdapter extends PagerAdapter implements OnTouchListener{
private Context localContext;
private LayoutInflater inflater;
private List<DataModel> parseObjects = new ArrayList<DataModel>();
private List<Integer> res = new ArrayList<Integer>();
// Declare Variables
private ImageView viewPagerDisplayImage;
/**
*
* @param context : The context where to display
* @param parseObjects : The ParseObject to work with
*/
public ProfileImageAdapter(Context context, List<DataModel> parseObjects) {
this.localContext = context;
this.parseObjects = parseObjects;
inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public int getCount() {
return parseObjects.size();
}
@Override
public int getItemPosition(Object object) {
return POSITION_NONE;
}
@Override
public boolean isViewFromObject(View view, Object object) {
return (view == ((LinearLayout) object) && object != null);
}
/**
* What is the item to show
*/
@Override
public Object instantiateItem(ViewGroup container, int position) {
inflater = (LayoutInflater) localContext
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View itemView = inflater.inflate(R.layout.profile_image_item, container, false);
// Locate the Image View in viewpager_item.xml
viewPagerDisplayImage = (ImageView) itemView.findViewById(R.id.view_pager_display_image_view);
// Getting the image
try {
ParseFile imageFile = parseObjects.get(position).getImage();
if (imageFile != null) {
byte[] bitmapImageData = imageFile.getData();
Bitmap bitmap = BitmapFactory.decodeByteArray(bitmapImageData, 0, bitmapImageData.length);
viewPagerDisplayImage.setImageBitmap(bitmap);
viewPagerDisplayImage.setOnTouchListener(this);
// Add viewpager_item.xml to ViewPager
itemView.setTag("VALID");
((ViewPager) container).addView(itemView);
} else {
((ViewPager) container).addView(itemView);
itemView.setTag("INVALID");
destroyItem(container, position, itemView);
}
} catch (ParseException e) {
e.printStackTrace();
}
return itemView;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
// Remove viewpager_item.xml from ViewPager
//((ViewPager) container).invalidate();
((ViewPager) container).removeView((View) object);
}
}
public class PageViewerProfileImages extends Activity {
private ViewPager viewPager;
private ProfileImageAdapter profileImageAdapter;
private UserModel userModel = new UserModel();
// Create the Page View for the Profile Images
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.profile_pager);
List<DataModel> parseObjects = userModel.getDataModels();
viewPager = (ViewPager) findViewById(R.id.pagerProfile);
profileImageAdapter = new ProfileImageAdapter(this, parseObjects);
// Setting the adapter
viewPager.findViewWithTag("VALID");
viewPager.setAdapter(profileImageAdapter);
}
}
if(imageUrl!=null){ // write code to add image url in your list, which will you pass in your adapter. }
if(imageUrl!=null){ // write code to add image url in your list, which will you pass in your adapter. }
使用它之后,它將僅將那些具有一定值的值傳遞給適配器,然后它將起作用。
當您通過圖像URL列表並在適配器列表中分配值時,可以將此條件放置在適配器中。 然后在分配您的值之前,請檢查相同條件,然后分配。
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