使用image-loader异步加载图片

1. 主类-获得图片的地址

关键点：

1>.良好的代码风格：

    init();

    getdata();

    setadapter();

2>loader = new AsyncLoader(context);

package com.example.androidtest;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import org.json.JSONArray;
import org.json.JSONObject;

import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;


import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.GridView;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;

/**
 * 应用
 * 
 * @author tf
 * 
 */
public class AscTaskActivity extends Activity {

	private GridView picgrid;
	private List<Map<String, String>> list;
	private HashMap<String, String> map;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		getWindow().requestFeature(Window.FEATURE_NO_TITLE);
		setContentView(R.layout.activity_pic_list);

		initView();
		getData();
		VideoListAdapter adapter = new VideoListAdapter(this, list);
		picgrid.setAdapter(adapter);
	}

	private void getData() {
		list = new ArrayList<Map<String, String>>();
		for (int i = 0; i < 10; i++) {
			Map<String, String> map = new HashMap<String, String>();
			map.put("pic_adress", "http://192.168.1.107:8080/MobileSafeServer/pic1.png");
		
			list.add(map);
		}
		
	}
	
	private void initView() {
		picgrid = (GridView) findViewById(R.id.picgrid);
	}



	class VideoListAdapter extends BaseAdapter {
		private AsyncLoader loader;
		private Context context;
		private List<Map<String, String>> data;
		private LayoutInflater inflater;

		public VideoListAdapter(Context context, List<Map<String, String>> list) {
			this.context = context;
			this.data = list;
			inflater = LayoutInflater.from(context);
			loader = new AsyncLoader(context);
			
		}

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

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

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

		
		@SuppressLint("ResourceAsColor")
		@Override
		public View getView(final int position, View convertView,
				ViewGroup parent) {
			final ViewHolder holder;
			if (null == convertView) {
				convertView = inflater.inflate(R.layout.pic_grid_item, null);
				holder = new ViewHolder();
				holder.pic_iamge_icon = (ImageView) convertView
						.findViewById(R.id.pic_iamge_icon);

				convertView.setTag(holder);

			} else {
				holder = (ViewHolder) convertView.getTag();
			}
		   //   holder.pic_iamge_icon.setText(data.get(position).get("pic_adress"));
			
			loader.displayImage(data.get(position).get("pic_adress"),
					
					holder.pic_iamge_icon);
		return convertView;
		}

		// 视图容器类,属性对应布局文件元素
		private class ViewHolder {
            ImageView pic_iamge_icon;
          //  TextView pic_iamge_icon;
		}

	}
}

2.AsyncLoader

关键点：

imageLoader.init(ImageLoaderConfiguration.createDefault(context));

public void displayImage(String uri, ImageView imageView) {
imageLoader.init(ImageLoaderConfiguration.createDefault(context));
imageLoader.displayImage(uri, new ImageViewAware(imageView, false),
options);
}

package com.example.androidtest;

import android.content.Context;
import android.graphics.Bitmap;
import android.widget.ImageView;

import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
import com.nostra13.universalimageloader.core.assist.ImageScaleType;
import com.nostra13.universalimageloader.core.imageaware.ImageViewAware;
import com.nostra13.universalimageloader.core.listener.ImageLoadingListener;

public class AsyncLoader {

	private DisplayImageOptions options;
	private ImageLoader imageLoader;
	private Context context;

	public AsyncLoader(Context context) {
		super();
		this.context = context;
		options = new DisplayImageOptions.Builder()
				.showImageOnLoading(R.drawable.default_image) // 璁剧疆鍥剧墖鍦ㄤ笅杞芥湡闂存樉绀虹殑鍥剧墖
				.showImageForEmptyUri(R.drawable.default_image)// 璁剧疆鍥剧墖Uri涓虹┖鎴栨槸閿欒�鐨勬椂鍊欐樉绀虹殑鍥剧墖
				.showImageOnFail(R.drawable.default_image) // 璁剧疆鍥剧墖鍔犺浇/瑙ｇ爜杩囩▼涓�敊璇�椂鍊欐樉绀虹殑鍥剧墖
				.cacheInMemory(true)// 璁剧疆涓嬭浇鐨勫浘鐗囨槸鍚︾紦瀛樺湪鍐呭瓨涓?				.cacheOnDisk(true)// 璁剧疆涓嬭浇鐨勫浘鐗囨槸鍚︾紦瀛樺湪SD鍗′腑
				// .considerExifParams(true) //鏄�惁鑰冭檻JPEG鍥惧儚EXIF鍙傛暟锛堟棆杞�紝缈昏浆锛?				// .imageScaleType(ImageScaleType.EXACTLY_STRETCHED)//璁剧疆鍥剧墖浠ュ�浣曠殑缂栫爜鏂瑰紡鏄剧ず
				.bitmapConfig(Bitmap.Config.RGB_565)// 璁剧疆鍥剧墖鐨勮В鐮佺被鍨?/
				// .delayBeforeLoading(int delayInMillis)//int
				// delayInMillis涓轰綘璁剧疆鐨勪笅杞藉墠鐨勫欢杩熸椂闂?				// 璁剧疆鍥剧墖鍔犲叆缂撳瓨鍓嶏紝瀵筨itmap杩涜�璁剧疆
				// .preProcessor(BitmapProcessor preProcessor)
				.resetViewBeforeLoading(false)// 璁剧疆鍥剧墖鍦ㄤ笅杞藉墠鏄�惁閲嶇疆锛屽�浣?				.imageScaleType(ImageScaleType.EXACTLY)

				.build();// 鏋勫缓瀹屾垚
		imageLoader = ImageLoader.getInstance();
		// type =new PreferencesHelper(context,
		// Constant.PRE_SETTING_FILE).getValueInt(Constant.PRE_SETTING_IMAGE_KEY);
		// netWorkType =AndroidUtil.getNetWorkType(context);
	}

	public AsyncLoader(Context context, int resId) {
		super();
		this.context = context;
		options = new DisplayImageOptions.Builder().showImageOnLoading(resId) // 璁剧疆鍥剧墖鍦ㄤ笅杞芥湡闂存樉绀虹殑鍥剧墖
				.showImageForEmptyUri(resId)// 璁剧疆鍥剧墖Uri涓虹┖鎴栨槸閿欒�鐨勬椂鍊欐樉绀虹殑鍥剧墖
				.showImageOnFail(resId) // 璁剧疆鍥剧墖鍔犺浇/瑙ｇ爜杩囩▼涓�敊璇�椂鍊欐樉绀虹殑鍥剧墖
				.cacheInMemory(true)// 璁剧疆涓嬭浇鐨勫浘鐗囨槸鍚︾紦瀛樺湪鍐呭瓨涓?				.cacheOnDisk(true)// 璁剧疆涓嬭浇鐨勫浘鐗囨槸鍚︾紦瀛樺湪SD鍗′腑
				// .considerExifParams(true) //鏄�惁鑰冭檻JPEG鍥惧儚EXIF鍙傛暟锛堟棆杞�紝缈昏浆锛?				// .imageScaleType(ImageScaleType.EXACTLY_STRETCHED)//璁剧疆鍥剧墖浠ュ�浣曠殑缂栫爜鏂瑰紡鏄剧ず
				.bitmapConfig(Bitmap.Config.RGB_565)// 璁剧疆鍥剧墖鐨勮В鐮佺被鍨?/
				// .delayBeforeLoading(int delayInMillis)//int
				// delayInMillis涓轰綘璁剧疆鐨勪笅杞藉墠鐨勫欢杩熸椂闂?				// 璁剧疆鍥剧墖鍔犲叆缂撳瓨鍓嶏紝瀵筨itmap杩涜�璁剧疆
				// .preProcessor(BitmapProcessor preProcessor)
				.resetViewBeforeLoading(false)// 璁剧疆鍥剧墖鍦ㄤ笅杞藉墠鏄�惁閲嶇疆锛屽�浣?				.imageScaleType(ImageScaleType.EXACTLY)

				.build();// 鏋勫缓瀹屾垚

		imageLoader = ImageLoader.getInstance();
	}

	public void displayImage(String uri, ImageView imageView) {
		imageLoader.init(ImageLoaderConfiguration.createDefault(context));
		imageLoader.displayImage(uri, new ImageViewAware(imageView, false),
				options);
	}

	public void displayImageWithUri(String uri, ImageView imageView) {
		imageLoader.displayImage(uri, new ImageViewAware(imageView, false),
				options);
	}

	public void displayImage(String uri, ImageView imageView,
			ImageLoadingListener listener) {
		
	
		imageLoader.displayImage(uri, new ImageViewAware(imageView, false),
				options, listener);
	}

	public void displayImageBG(String uri, ImageView imageView) {
		imageLoader.displayImage(uri, new BgImageAware(imageView), options);
	}

	public void displayImageWithFile(String path, ImageView imageView) {
		imageLoader.displayImage("file://" + path, imageView);
	}

	/*
	 * public void displayImageAuto(String uri, ImageView imageView) {
	 * imageLoader
	 * .displayImage(GlobalApplication.getInstance().getBaseUrl()+getNetTypeURi
	 * ()+uri, new ImageViewAware(imageView,false), options, new
	 * ImageLoadingListener() {
	 * 
	 * @Override public void onLoadingStarted(String arg0, View arg1) { // TODO
	 * Auto-generated method stub
	 * 
	 * }
	 * 
	 * @Override public void onLoadingFailed(String arg0, View arg1, FailReason
	 * arg2) { // TODO Auto-generated method stub
	 * 
	 * }
	 * 
	 * @Override public void onLoadingComplete(String arg0, View view, Bitmap
	 * loadedImage) { if(loadedImage!=null){ UIUtils.setAutoLayout(context,
	 * view, loadedImage); } }
	 * 
	 * @Override public void onLoadingCancelled(String arg0, View arg1) { //
	 * TODO Auto-generated method stub
	 * 
	 * } }); }
	 */

}

3.BgImageAware.java

关键点：

记住要导包：image-loader.jar

和添加权限

<uses-permission android:name="android.permission.INTERNET" />
 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> 

package com.example.androidtest;

import java.lang.ref.Reference;
import java.lang.ref.WeakReference;

import android.annotation.SuppressLint;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.os.Looper;
import android.view.View;
import android.view.ViewGroup;

import com.nostra13.universalimageloader.core.assist.ViewScaleType;
import com.nostra13.universalimageloader.core.imageaware.ImageAware;
import com.nostra13.universalimageloader.utils.L;

@SuppressLint("NewApi")
public class BgImageAware implements ImageAware {

	public static final String WARN_CANT_SET_DRAWABLE = "Can't set a drawable into view. You should call ImageLoader on UI thread for it.";
	public static final String WARN_CANT_SET_BITMAP = "Can't set a bitmap into view. You should call ImageLoader on UI thread for it.";

	protected Reference<View> viewRef;
	protected boolean checkActualViewSize;

	public BgImageAware(View view) {
		this(view, true);
	}

	public BgImageAware(View view, boolean checkActualViewSize) {
		this.viewRef = new WeakReference<View>(view);
		this.checkActualViewSize = checkActualViewSize;
	}

	@Override
	public int getWidth() {
		View view = viewRef.get();
		if (view != null) {
			final ViewGroup.LayoutParams params = view.getLayoutParams();
			int width = 0;
			if (checkActualViewSize && params != null
					&& params.width != ViewGroup.LayoutParams.WRAP_CONTENT) {
				width = view.getWidth(); // Get actual image width
			}
			if (width <= 0 && params != null)
				width = params.width; // Get layout width parameter
			return width;
		}
		return 0;
	}

	@Override
	public int getHeight() {
		View view = viewRef.get();
		if (view != null) {
			final ViewGroup.LayoutParams params = view.getLayoutParams();
			int height = 0;
			if (checkActualViewSize && params != null
					&& params.height != ViewGroup.LayoutParams.WRAP_CONTENT) {
				height = view.getHeight(); // Get actual image height
			}
			if (height <= 0 && params != null)
				height = params.height; // Get layout height parameter
			return height;
		}
		return 0;
	}

	@Override
	public ViewScaleType getScaleType() {
		return ViewScaleType.CROP;
	}

	@Override
	public View getWrappedView() {
		return viewRef.get();
	}

	@Override
	public boolean isCollected() {
		return viewRef.get() == null;
	}

	@Override
	public int getId() {
		View view = viewRef.get();
		return view == null ? super.hashCode() : view.hashCode();
	}

	@Override
	public boolean setImageDrawable(Drawable drawable) {
		if (Looper.myLooper() == Looper.getMainLooper()) {
			View view = viewRef.get();
			if (view != null) {
				if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
					view.setBackground(drawable);
				} else {
					view.setBackgroundDrawable(drawable);
				}
				return true;
			}
		} else {
			L.w(WARN_CANT_SET_DRAWABLE);
		}
		return false;
	}

	@Override
	public boolean setImageBitmap(Bitmap bitmap) {
		if (Looper.myLooper() == Looper.getMainLooper()) {
			View view = viewRef.get();
			if (view != null) {
				Drawable drawable = bitmap == null ? null : new BitmapDrawable(
						view.getResources(), bitmap);
				if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
					view.setBackground(drawable);
				} else {
					view.setBackgroundDrawable(drawable);
				}
				return true;
			}
		} else {
			L.w(WARN_CANT_SET_BITMAP);
		}
		return false;
	}
}