В пользовательской галерее, при прокрутке изображений, оттачивающих

Question

Я создал собственную галерею для выбора нескольких фотографий в android. Я использую AsynTask для установки растрового изображения. Когда я прокручиваю свой экран, изображения заменяются следующими изображениями и установкой на предыдущее местоположение.

Answer 1

общественный класс CustomGallery расширяет активность реализует View.OnClickListener {

/** * Создано Рамеш на 04-Jan-16. */

private ImageAdapter imageAdapter; 
private String[] arrPath; 
private boolean[] thumbnailsSelection; 
private int ids[]; 
private int count; 
String imgDecode; 
ArrayList<String> imageIdList = new ArrayList<String>(); 
final int MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE = 1; 


@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.custom_gallery); 


    System.out.println("MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE-->" + MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE); 

    if (Integer.valueOf(Build.VERSION.SDK_INT)>=23) { 

     if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.READ_EXTERNAL_STORAGE)) { 

      // Show an expanation to the user *asynchronously* -- don't block 
      // this thread waiting for the user's response! After the user 
      // sees the explanation, try again to request the permission. 
      Log.i("Permission Log", " Permission Granted----> if cond"); 
      ActivityCompat.requestPermissions(this, 
        new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 
        MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE); 

     } else { 

      // No explanation needed, we can request the permission. 
      Log.i("Permission Log", " Permission Granted----> else cond"); 
      ActivityCompat.requestPermissions(this, 
        new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 
        MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE); 

      // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an 
      // app-defined int constant. The callback method gets the 
      // result of the request. 
     } 
    } 

    else{ 

     final String[] columns = {MediaStore.Images.Media.DATA, MediaStore.Images.Media._ID}; 
    Log.i(MediaStore.Images.Media.DATA, "Media Store Images.Media.Data"); 
    Log.i(MediaStore.Images.Media._ID, "Media Store Images.Media_id"); 
    final String orderBy = MediaStore.Images.ImageColumns.DATE_TAKEN + " DESC" ; 

    Cursor imageCursor = getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, columns, null, null, 
      orderBy); 

    final int image_column_index = imageCursor.getColumnIndex(MediaStore.Images.Media._ID); 
    imgDecode = imageCursor.getColumnName(image_column_index); 
    this.count = imageCursor.getCount(); 
    this.arrPath = new String[this.count]; 
    ids = new int[count]; 
    this.thumbnailsSelection = new boolean[this.count]; 

    for (int i = 0; i < this.count; i++) { 
     imageCursor.moveToPosition(i); 
     ids[i] = imageCursor.getInt(image_column_index); 
     int dataColumnIndex = imageCursor.getColumnIndex(MediaStore.Images.Media.DATA); 
     arrPath[i] = imageCursor.getString(dataColumnIndex); 
    } 

    GridView imagegrid = (GridView) findViewById(R.id.PhoneImageGrid); 
    imageAdapter = new ImageAdapter(); 
    imagegrid.setAdapter(imageAdapter); 
    imageCursor.close(); 

    final Button selectBtn = (Button) findViewById(R.id.selectBtn); 
    selectBtn.setOnClickListener(this); 

    Button cancelBtn = (Button) findViewById(R.id.cancelBtn); 
    cancelBtn.setOnClickListener(this); 

    } 



} 


@Override 
public void onBackPressed() { 
    super.onBackPressed(); 
    setResult(Activity.RESULT_CANCELED); 

} 

@Override 
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) { 
    switch (requestCode) { 
     case MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE: { 
      // If request is cancelled, the result arrays are empty. 
      if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) { 

       // permission was granted, yay! Do the 
       // contacts-related task you need to do. 
       Log.i(" Permission Log", " Permission Granted"); 
       final String[] columns = {MediaStore.Images.Media.DATA, MediaStore.Images.Media._ID}; 
       Log.i(MediaStore.Images.Media.DATA, "Media Store Images.Media.Data"); 
       Log.i(MediaStore.Images.Media._ID, "Media Store Images.Media_id"); 
       final String orderBy = MediaStore.Images.Media._ID; 

    Cursor imageCursor = getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, columns, null, null, orderBy); 
    //final int image_column_index = imageCursor.getColumnIndex(MediaStore.Images.Media._ID); 
    final int image_column_index = imageCursor.getColumnIndex(MediaStore.Images.Media._ID); 

    imgDecode = imageCursor.getColumnName(image_column_index); 
    this.count = imageCursor.getCount(); 
    this.arrPath = new String[this.count]; 
    ids = new int[count]; 
    this.thumbnailsSelection = new boolean[this.count]; 

    for (int i = 0; i < this.count; i++) { 
     imageCursor.moveToPosition(i); 
     ids[i] = imageCursor.getInt(image_column_index); 
     int dataColumnIndex = imageCursor.getColumnIndex(MediaStore.Images.Media.DATA); 
     arrPath[i] = imageCursor.getString(dataColumnIndex); 
    } 

    GridView image_grid = (GridView) findViewById(R.id.PhoneImageGrid); 
    imageAdapter = new ImageAdapter(); 
    image_grid.setAdapter(imageAdapter); 
    imageCursor.close(); 

    final Button selectBtn = (Button) findViewById(R.id.selectBtn); 
    selectBtn.setOnClickListener(this); 

    Button cancelBtn = (Button) findViewById(R.id.cancelBtn); 
    cancelBtn.setOnClickListener(this); 

      } else { 

       // permission denied, boo! Disable the 
       // functionality that depends on this permission. 
       Log.i("Permission Log", " else cond"); 
      } 
      return; 
     } 

     // other 'case' lines to check for other 
     // permissions this app might request 
    } 
} 


private void setBitmap(final ImageView iv, final int id) { 

    new AsyncTask<Void, Void, Bitmap>() { 

     @Override 
     protected Bitmap doInBackground(Void... params) { 
      return MediaStore.Images.Thumbnails.getThumbnail(getApplicationContext().getContentResolver(), id, 
        MediaStore.Images.Thumbnails.MINI_KIND, null); 
     } 

     @Override 
     protected void onPostExecute(Bitmap result) { 
      super.onPostExecute(result); 
      iv.setImageBitmap(result); 
     } 
    }.execute(); 
} 

@Override 
public void onClick(View v) { 
    switch (v.getId()) { 

     case R.id.selectBtn: 
      final int len = thumbnailsSelection.length; 

      String selectImages = ""; 
      int cnt = 0; 
      for (int i = 0; i < len; i++) { 
       if (thumbnailsSelection[i]) { 
        cnt++; 
        Log.i("Custom Gallery", "Inside for loop----->"); 

        selectImages = selectImages + arrPath[i]; 
        System.out.println("Array Path--" + arrPath[i]); 
        imageIdList.add(arrPath[i]); 

       } 

      } 

      if (cnt == 0) { 

       Toast.makeText(getApplicationContext(), "Please select at least one image", Toast.LENGTH_LONG).show(); 
      } else if (cnt > 5) { 


       Toast.makeText(getApplicationContext(), "You can select only 5 images", Toast.LENGTH_LONG).show(); 


      } else { 

       // System.out.println("My ListItem -->>" + imageIdList); 
       /* Bundle bundel = new Bundle(); 
       bundel.putStringArrayList("key", imageIdList); 
       Intent intent = new Intent(getApplicationContext(), AddVehicle.class); 
       intent.putExtras(bundel); 
       startActivity(intent); 
       finish();*/ 

       Intent returnIntent = new Intent(); 
       returnIntent.putStringArrayListExtra("image-list", imageIdList); 
       setResult(Activity.RESULT_OK, returnIntent); 
       finish(); 

      } 
      break; 


     case R.id.cancelBtn: 
      onBackPressed(); 
      break; 

    } 
} 


public class ImageAdapter extends BaseAdapter { 
    private LayoutInflater mInflater; 

    public ImageAdapter() { 
     mInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
    } 

    public int getCount() { 
     return count; 
    } 

    public Object getItem(int position) { 
     return position; 
    } 

    public long getItemId(int position) { 
     return position; 
    } 

    public View getView(int position, View convertView, ViewGroup parent) { 
     final ViewHolder holder; 


     /*if (convertView == null) {*/ 

      holder = new ViewHolder(); 
      convertView = mInflater.inflate(R.layout.gallery_item, null); 
      holder.imageview = (ImageView) convertView.findViewById(R.id.thumbImage); 
      holder.checkbox = (CheckBox) convertView.findViewById(R.id.itemCheckBox); 

      convertView.setTag(holder); 
     /* } else { 

      holder = (ViewHolder) convertView.getTag(); 
     } */ 


     holder.checkbox.setId(position); 
     holder.imageview.setId(position); 
     holder.checkbox.setOnClickListener(new View.OnClickListener() { 

      public void onClick(View v) { 
       CheckBox cb = (CheckBox) v; 

       int id = cb.getId(); 
       if (thumbnailsSelection[id]) { 
        cb.setChecked(false); 
        System.out.println("if thumbnail selection"); 
        thumbnailsSelection[id] = false; 
       } else { 
        System.out.println("else thumbnail selection"); 
        cb.setChecked(true); 
        thumbnailsSelection[id] = true; 
       } 
      } 
     }); 

     holder.imageview.setOnClickListener(new View.OnClickListener() { 

      public void onClick(View v) { 
       int id = holder.checkbox.getId(); 
       if (thumbnailsSelection[id]) { 
        Log.i("Custom Gallery", "if image click----->"); 

        holder.checkbox.setChecked(false); 
        thumbnailsSelection[id] = false; 
       } else { 
        Log.i("Custom Gallery", "if image not clicked----->"); 

        holder.checkbox.setChecked(true); 
        thumbnailsSelection[id] = true; 


       } 
      } 
     }); 

     try { 

      setBitmap(holder.imageview, ids[position]); 


     } catch (Throwable e) { 
      Log.i(e.getMessage(), "Exception:"); 
     } 
     holder.checkbox.setChecked(thumbnailsSelection[position]); 
     holder.id = position; 

     return convertView; 
    } 
} 

class ViewHolder { 
    ImageView imageview; 
    CheckBox checkbox; 
    int id; 
} 

}