Implement a photo bar using android.widget.Gallery, with custom BaseAdapter, and custom object.
In this example, I will implement a photo bar using android.widget.Gallery.
We will implement MyAdapter extends BaseAdapter, it hold a ArrayList of our custom object ImageItem. In the constructor of MyAdapter, an empty ArrayList of ImageItem will be new. And a method addImageItem is implemented to add new items into the ArrayList.
insertDummyImageItem(3) is a dummy method to add new items into the ArrayList of MyAdapter. As a example, all items have the same bitmap - R.drawable.icon. After items inserted, we have to call notifyDataSetChanged() of the MyAdapter to update the photo bar.
In such a approach, we can add new item on runtime. We will do more on coming post "Update BaseAdapter in backgrond Thread, to insert Gallery items in run-time.".
We will implement MyAdapter extends BaseAdapter, it hold a ArrayList of our custom object ImageItem. In the constructor of MyAdapter, an empty ArrayList of ImageItem will be new. And a method addImageItem is implemented to add new items into the ArrayList.
insertDummyImageItem(3) is a dummy method to add new items into the ArrayList of MyAdapter. As a example, all items have the same bitmap - R.drawable.icon. After items inserted, we have to call notifyDataSetChanged() of the MyAdapter to update the photo bar.
In such a approach, we can add new item on runtime. We will do more on coming post "Update BaseAdapter in backgrond Thread, to insert Gallery items in run-time.".
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| package com.AndroidPhotoBar;import java.util.ArrayList;import android.app.Activity;import android.content.Context;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.os.Bundle;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.Gallery;import android.widget.ImageView;public class AndroidPhotoBarActivity extends Activity {ArrayList<ImageItem> arrayImageItem;MyAdapter myAdapter; public class ImageItem { Bitmap bitmapImage; ImageItem(){ //To simplify, we use a default image here bitmapImage = BitmapFactory.decodeResource( AndroidPhotoBarActivity.this.getResources(), R.drawable.icon); } public Bitmap getImage(){ return bitmapImage; } } Gallery myPhotoBar;/** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); myPhotoBar = (Gallery)findViewById(R.id.photobar); myAdapter = new MyAdapter(this); //init myAdapter without ImageItem //insert dummy ImageItem into myAdapter insertDummyImageItem(2); myPhotoBar.setAdapter(myAdapter); //insert dummy ImageItem into myAdapter in Run time insertDummyImageItem(3); myAdapter.notifyDataSetChanged(); } private void insertDummyImageItem(int cnt){ //Insert dummy ImageItem into myAdapter for(int i = 0; i < cnt; i++){ myAdapter.addImageItem(new ImageItem()); } } public class MyAdapter extends BaseAdapter { Context context; ArrayList<ImageItem> _arrayImageItem; MyAdapter(Context c){ context = c; _arrayImageItem = new ArrayList<ImageItem>(); } public void addImageItem(ImageItem item){ _arrayImageItem.add(item); }public int getCount() { // TODO Auto-generated method stub return _arrayImageItem.size();}public Object getItem(int position) { // TODO Auto-generated method stub return _arrayImageItem.get(position);}public long getItemId(int position) { // TODO Auto-generated method stub return position;}public View getView(int position, View convertView, ViewGroup parent) { // TODO Auto-generated method stub ImageView imageView; imageView = new ImageView(context); imageView.setLayoutParams(new Gallery.LayoutParams(150, 150)); imageView.setScaleType(ImageView.ScaleType.CENTER_CROP); imageView.setImageBitmap(_arrayImageItem.get(position).getImage()); return imageView;}}}akmwww.cdacians.com |
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