Android:万能框架——universal-image-loader——GalleryView异步加载图片

最新推荐文章于 2015-03-29 13:08:57 发布

转载最新推荐文章于 2015-03-29 13:08:57 发布 · 1.2k 阅读

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#Gallery #universal-image-load #Android #框架 #异步

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本文详细介绍了如何使用画廊组件实现异步加载图片，包括初始化、适配器配置及点击事件处理。

import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;
import com.nostra13.example.universalimageloader.Constants.Extra;
import com.nostra13.universalimageloader.core.DisplayImageOptions;


/**
 *	画廊异步加载组件 
 */
@SuppressWarnings("deprecation")
public class ImageGalleryActivity extends BaseActivity {

	String[] imageUrls;

	DisplayImageOptions options;

	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.ac_image_gallery);

		Bundle bundle = getIntent().getExtras();
		imageUrls = bundle.getStringArray(Extra.IMAGES);

		options = new DisplayImageOptions.Builder()
			.showImageOnLoading(R.drawable.ic_stub)// 正在加载图片
			.showImageForEmptyUri(R.drawable.ic_empty)//uri为空的时候显示
			.showImageOnFail(R.drawable.ic_error)// 加载失败时显示
			.cacheInMemory(true)//设置是否先从内存读取
			.cacheOnDisc(true)//设置是否先从磁盘读取
			.considerExifParams(true)
			.bitmapConfig(Bitmap.Config.RGB_565)
			.build();

		Gallery gallery = (Gallery) findViewById(R.id.gallery);
		gallery.setAdapter(new ImageGalleryAdapter());//添加适配器
		gallery.setOnItemClickListener(new OnItemClickListener() {
			@Override
			public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
				startImagePagerActivity(position);
			}
		});
	}

	private void startImagePagerActivity(int position) {
		Intent intent = new Intent(this, ImagePagerActivity.class);
		intent.putExtra(Extra.IMAGES, imageUrls);
		intent.putExtra(Extra.IMAGE_POSITION, position);
		startActivity(intent);
	}

	private class ImageGalleryAdapter extends BaseAdapter {
		@Override
		public int getCount() {//返回 “画廊” 的总长度
			return imageUrls.length;
		}

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

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

		/**
		 * 如果不能将convertView（old组件）转化成新组件，就重新创建一个组件
		 */
		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			ImageView imageView = (ImageView) convertView;
			if (imageView == null) {
				
				//加载新item
				imageView = (ImageView) getLayoutInflater().inflate(R.layout.item_gallery_image, parent, false);
			}
			
			//添加新任务到队列
			imageLoader.displayImage(imageUrls[position], imageView, options);
			
			return imageView;
		}
		
	}
}

源文件下载地址：http://pan.baidu.com/s/1bnf6CbX