[英]Delete a View from PagerAdapter in Android
我已经搜索了多个网站,android开发者网站,但碰巧遇到了麻烦,我不得不寻求社区的帮助。 所有帮助和建议将不胜感激。
问题 :
我总共从服务器收到12张图像(在此处解析),并在PagerAdapter中显示它们。 如果所有值都不都是null,则适配器代码可以正常工作,但有一个缺点是我允许将null值存储在服务器中。 当我从服务器取回整个列表时,我只想将那些视图包含在不包含null的适配器中。 示例:假设我得到5个空路径,然后我的适配器总共显示12个视图(其中7个带有图像,其余为空白页)。
我的适配器代码:
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,它将仅将那些具有一定值的值传递给适配器,然后它将起作用。
当您通过图像URL列表并在适配器列表中分配值时,可以将此条件放置在适配器中。 然后在分配您的值之前,请检查相同条件,然后分配。
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