如何將回調從適配器返回到片段類

我有一個網格視圖，圖像和關聯複選框顯示在片段中。片段類包括從圖庫或相機捕獲圖像的方法。我如何引入一個回調從Adapter到Fragment類，並且已經點擊了項目引用，以便捕獲/加載圖像可以從Fragment類中執行？如何將回調從適配器返回到片段類

片段類其中網格必須被加載來自照相機或畫廊圖像捕獲：

public class SellMainFrag extends Fragment{ 

private int REQUEST_CAMERA = 0, SELECT_FILE = 1; 
private Button btnSelect; 
private ImageView ivImage; 
private String userChoosenTask; 

public SellMainFrag() { 
    // Required empty public constructor 
} 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
} 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
    View view = inflater.inflate(R.layout.sell_main, container, false); 

    int iconSize=getResources().getDimensionPixelSize(android.R.dimen.app_icon_size); 

    ImageGridAdapter adapter = new ImageGridAdapter(view.getContext(), iconSize); 
    GridView gridview = (GridView) view.findViewById(R.id.gridView1); 
    gridview.setAdapter(adapter); 

    return view; 
} 

@Override 
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) { 
    switch (requestCode) { 
     case Utility.MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE: 
      if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) { 
       if(userChoosenTask.equals("Take Photo")) 
        cameraIntent(); 
       else if(userChoosenTask.equals("Choose from Library")) 
        galleryIntent(); 
      } else { 
       //code for deny 
      } 
      break; 
    } 
} 

private void selectImage() { 
    final CharSequence[] items = { "Take Photo", "Choose from Library", "Cancel" }; 

    AlertDialog.Builder builder = new AlertDialog.Builder(this.getActivity()); 
    builder.setTitle("Add Photo!"); 
    builder.setItems(items, new DialogInterface.OnClickListener() { 
     @Override 
     public void onClick(DialogInterface dialog, int item) { 
      boolean result=Utility.checkPermission(getContext()); 

      if (items[item].equals("Take Photo")) { 
       userChoosenTask ="Take Photo"; 
       if(result) 
        cameraIntent(); 

      } else if (items[item].equals("Choose from Library")) { 
       userChoosenTask ="Choose from Library"; 
       if(result) 
        galleryIntent(); 

      } else if (items[item].equals("Cancel")) { 
       dialog.dismiss(); 
      } 
     } 
    }); 
    builder.show(); 
} 

private void galleryIntent() 
{ 
    Intent intent = new Intent(); 
    intent.setType("image/*"); 
    intent.setAction(Intent.ACTION_GET_CONTENT);// 
    startActivityForResult(Intent.createChooser(intent, "Select File"),SELECT_FILE); 
} 

private void cameraIntent() 
{ 
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); 
    startActivityForResult(intent, REQUEST_CAMERA); 
} 

@Override 
public void onActivityResult(int requestCode, int resultCode, Intent data) { 
    super.onActivityResult(requestCode, resultCode, data); 

    if (resultCode == Activity.RESULT_OK) { 
     if (requestCode == SELECT_FILE) 
      onSelectFromGalleryResult(data); 
     else if (requestCode == REQUEST_CAMERA) 
      onCaptureImageResult(data); 
    } 
} 

private void onCaptureImageResult(Intent data) { 
    Bitmap thumbnail = (Bitmap) data.getExtras().get("data"); 
    ByteArrayOutputStream bytes = new ByteArrayOutputStream(); 
    thumbnail.compress(Bitmap.CompressFormat.JPEG, 90, bytes); 

    File destination = new File(Environment.getExternalStorageDirectory(), 
      System.currentTimeMillis() + ".jpg"); 

    FileOutputStream fo; 
    try { 
     destination.createNewFile(); 
     fo = new FileOutputStream(destination); 
     fo.write(bytes.toByteArray()); 
     fo.close(); 
    } catch (FileNotFoundException e) { 
     e.printStackTrace(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 

    ivImage.setImageBitmap(thumbnail); 
} 

@SuppressWarnings("deprecation") 
private void onSelectFromGalleryResult(Intent data) { 

    Bitmap bm=null; 
    if (data != null) { 
     try { 
      bm = MediaStore.Images.Media.getBitmap(getContext().getContentResolver(), data.getData()); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
    } 

    ivImage.setImageBitmap(bm); 
} 

}

適配器類，其包括偵聽來捕獲點擊：

public class ImageGridAdapter extends BaseAdapter{ 
private Context mContext; 
private int mIconSize; 
private static LayoutInflater inflater=null; 

private String[] web = { 
     "Doctors","Movies","Dentists","Restaurants","Car"} ; 

private int[] imageId = { 
     R.mipmap.doctors, 
     R.mipmap.dentists, 
     R.mipmap.restaurants, 
     R.mipmap.carmechanic, 
     R.mipmap.ic_launcher 
}; 

public ImageGridAdapter(Context mContext, int mIconSize) { 
    super(); 
    this.mContext = mContext; 
    this.mIconSize = mIconSize; 
    inflater = (LayoutInflater)mContext. 
      getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
} 

@Override 
public int getCount() { 
    // TODO Auto-generated method stub 
    return imageId.length; 
} 

@Override 
public Object getItem(int position) { 
    // TODO Auto-generated method stub 
    return null; 
} 

@Override 
public long getItemId(int position) { 
    // TODO Auto-generated method stub 
    return 0; 
} 

public class Holder 
{ 
    CheckBox ck; 
    ImageView img; 
} 

@Override 
public View getView(int position, View convertView, ViewGroup parent) { 

    Holder holder=new Holder(); 
    View rowView; 

    rowView = inflater.inflate(R.layout.sell_main_images, null); 
    holder.ck=(CheckBox) rowView.findViewById(R.id.chk1); 
    holder.img=(ImageView) rowView.findViewById(R.id.imageView1); 

    holder.ck.isChecked(); 
    holder.img.setImageResource(imageId[position]); 

    rowView.setOnClickListener(new View.OnClickListener() { 

     @Override 
     public void onClick(View v) { 
      // TODO Auto-generated method stub 
      // How do I introduce a callback to Fragment class with the item reference that has been clicked so that capture/loading images can be performed from the Fragment class? 

     } 
    }); 

    return rowView; 
} 

}

來源

2016-09-27 dacscan3669

嘗試使用接口..按照給定的鏈接瞭解更多信息[http://stackoverflow.com/questions/15444375/how-to-create-interface-between-fragment-and-adapter] –

就可以像即：

ImageGridAdapter

public class ImageGridAdapter extends BaseAdapter{ 
private Context mContext; 
private int mIconSize; 
private static LayoutInflater inflater=null; 
AdapterCallback callback; 

public interface AdapterCallback{ 
    void onItemClicked(int position); 
} 

private String[] web = { 
     "Doctors","Movies","Dentists","Restaurants","Car"} ; 

private int[] imageId = { 
     R.mipmap.doctors, 
     R.mipmap.dentists, 
     R.mipmap.restaurants, 
     R.mipmap.carmechanic, 
     R.mipmap.ic_launcher 
}; 

public ImageGridAdapter(Context mContext, int mIconSize, AdapterCallback callback) { 
    super(); 
    this.callback = callback; 
    this.mContext = mContext; 
    this.mIconSize = mIconSize; 
    inflater = (LayoutInflater)mContext. 
      getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
} 

@Override 
public int getCount() { 
    // TODO Auto-generated method stub 
    return imageId.length; 
} 

@Override 
public Object getItem(int position) { 
    // TODO Auto-generated method stub 
    return null; 
} 

@Override 
public long getItemId(int position) { 
    // TODO Auto-generated method stub 
    return 0; 
} 

public class Holder 
{ 
    CheckBox ck; 
    ImageView img; 
} 

@Override 
public View getView(int position, View convertView, ViewGroup parent) { 

    Holder holder=new Holder(); 
    View rowView; 

    rowView = inflater.inflate(R.layout.sell_main_images, null); 
    holder.ck=(CheckBox) rowView.findViewById(R.id.chk1); 
    holder.img=(ImageView) rowView.findViewById(R.id.imageView1); 

    holder.ck.isChecked(); 
    holder.img.setImageResource(imageId[position]); 

    rowView.setOnClickListener(new View.OnClickListener() { 

     @Override 
     public void onClick(View v) { 
      // TODO Auto-generated method stub 
      // How do I introduce a callback to Fragment class with the item reference that has been clicked so that capture/loading images can be performed from the Fragment class? 
       if(callback != null) { 
       callback.onItemClicked(position); 
       } 

     } 
    }); 

    return rowView; 
} 

}

而且片段

public class SellMainFrag extends Fragment implements AdapterCallback{ 

private int REQUEST_CAMERA = 0, SELECT_FILE = 1; 
private Button btnSelect; 
private ImageView ivImage; 
private String userChoosenTask; 

public SellMainFrag() { 
    // Required empty public constructor 
} 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
} 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
    View view = inflater.inflate(R.layout.sell_main, container, false); 

    int iconSize=getResources().getDimensionPixelSize(android.R.dimen.app_icon_size); 

    ImageGridAdapter adapter = new ImageGridAdapter(view.getContext(), iconSize, SellMainFrag.this); 
    GridView gridview = (GridView) view.findViewById(R.id.gridView1); 
    gridview.setAdapter(adapter); 

    return view; 
} 

@Override 
public void onItemClicked(int position){ 
    // call back here 
} 

@Override 
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) { 
    switch (requestCode) { 
     case Utility.MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE: 
      if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) { 
       if(userChoosenTask.equals("Take Photo")) 
        cameraIntent(); 
       else if(userChoosenTask.equals("Choose from Library")) 
        galleryIntent(); 
      } else { 
       //code for deny 
      } 
      break; 
    } 
} 

private void selectImage() { 
    final CharSequence[] items = { "Take Photo", "Choose from Library", "Cancel" }; 

    AlertDialog.Builder builder = new AlertDialog.Builder(this.getActivity()); 
    builder.setTitle("Add Photo!"); 
    builder.setItems(items, new DialogInterface.OnClickListener() { 
     @Override 
     public void onClick(DialogInterface dialog, int item) { 
      boolean result=Utility.checkPermission(getContext()); 

      if (items[item].equals("Take Photo")) { 
       userChoosenTask ="Take Photo"; 
       if(result) 
        cameraIntent(); 

      } else if (items[item].equals("Choose from Library")) { 
       userChoosenTask ="Choose from Library"; 
       if(result) 
        galleryIntent(); 

      } else if (items[item].equals("Cancel")) { 
       dialog.dismiss(); 
      } 
     } 
    }); 
    builder.show(); 
} 

private void galleryIntent() 
{ 
    Intent intent = new Intent(); 
    intent.setType("image/*"); 
    intent.setAction(Intent.ACTION_GET_CONTENT);// 
    startActivityForResult(Intent.createChooser(intent, "Select File"),SELECT_FILE); 
} 

private void cameraIntent() 
{ 
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); 
    startActivityForResult(intent, REQUEST_CAMERA); 
} 

@Override 
public void onActivityResult(int requestCode, int resultCode, Intent data) { 
    super.onActivityResult(requestCode, resultCode, data); 

    if (resultCode == Activity.RESULT_OK) { 
     if (requestCode == SELECT_FILE) 
      onSelectFromGalleryResult(data); 
     else if (requestCode == REQUEST_CAMERA) 
      onCaptureImageResult(data); 
    } 
} 

private void onCaptureImageResult(Intent data) { 
    Bitmap thumbnail = (Bitmap) data.getExtras().get("data"); 
    ByteArrayOutputStream bytes = new ByteArrayOutputStream(); 
    thumbnail.compress(Bitmap.CompressFormat.JPEG, 90, bytes); 

    File destination = new File(Environment.getExternalStorageDirectory(), 
      System.currentTimeMillis() + ".jpg"); 

    FileOutputStream fo; 
    try { 
     destination.createNewFile(); 
     fo = new FileOutputStream(destination); 
     fo.write(bytes.toByteArray()); 
     fo.close(); 
    } catch (FileNotFoundException e) { 
     e.printStackTrace(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 

    ivImage.setImageBitmap(thumbnail); 
} 

@SuppressWarnings("deprecation") 
private void onSelectFromGalleryResult(Intent data) { 

    Bitmap bm=null; 
    if (data != null) { 
     try { 
      bm = MediaStore.Images.Media.getBitmap(getContext().getContentResolver(), data.getData()); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
    } 

    ivImage.setImageBitmap(bm); 
} 

}

來源

2016-09-27 02:48:58

我看到消息的代碼'callback.onItemClicked（position）;' - 在內部類中訪問變量位置，需要聲明爲final。需要做些什麼來解決這個問題？ – dacscan3669

我看到代碼爲callback.onItemClicked（position）的消息; - 在內部類中訪問可變位置，需要聲明爲最終。需要做些什麼來解決這個問題？ – dacscan3669

宣佈它是最終的。 'public View getView（final int position，View convertView，ViewGroup parent）' –

首先從適配器之外傳遞列表。

//object which store your item 
public class SampleListItem{ 
    public String web; 
    public int image; 
    public boolean selected = false; //--> use this flag 

}

//適配器

public class SampleListItemAdapter extends BaseAdapter { 
    private Context context; 
    private List<SampleListItem> sampleList; 


    public SampleListItemAdapter (Context context, List<SampleListItem> sampleList) { 
     this.context = context; 
     this.sampleList= sampleList; 
    } 

    @Override 
    public int getCount() { 
     return sampleList.size(); 
    } 

    @Override 
    public Object getItem(int position) { 
     return sampleList.get(position); 
    } 

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

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     ViewHolder viewHolder; 
     if (convertView == null) { 
      convertView = LayoutInflater.from(context).inflate(R.layout.adapter, parent, false); 
      viewHolder = new ViewHolder(convertView); 
      convertView.setTag(viewHolder); 
     } else { 
      viewHolder = (ViewHolder) convertView.getTag(); 
     } 

     SampleListItem listItem= sampleList.get(position); 
     viewHolder.tv_web.setText(listItem.getName()); 


     int image = listItem.getImage(); 
     if (image != -1) { 
      viewHolder.iv_img.setImageResource(image); 
     } 

     return convertView; 
    } 

    public void updateList(List<SampleListItem> sampleList) { 
     this.sampleList = sampleList; 
     notifyDataSetChanged(); 
    } 

    static class ViewHolder { 
     @Bind(R.id.iv_img) 
     ImageView iv_img; 
     @Bind(R.id.tv_web) 
     TextView tv_web; 


     public ViewHolder(View view) { 
      ButterKnife.bind(this, view); 
     } 
    } 
}

//當您選擇的項目。使選定的標誌=真。其他人則認爲這是假的

SampleListItemAdapter adapter = new SampleListItemAdapter (activity, sampleList); 
//eg. you may change the any element in samepleList selected flag into true and //call updateList 
     if (adapter != null) { 
      adapter.updateList(sampleList); 
     }

//然後通過列表屏幕，得到一個選擇和處理圖像。 //我改變我的代碼來提供這個示例，如果是這樣的話，我可能錯過了一些名字。

來源

2016-09-27 02:57:11 kggoh

如何將回調從適配器返回到片段類

回答

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