20、长图的加载显示

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原创最新推荐文章于 2026-05-03 10:13:21 发布 353 阅读 AI 写同款· GEO 优化 ›

[size=medium] 有时候图片很长，预览只是其一部分，有个类似按钮点击之后加载全图并显示，类似于GIF的加载显示。

ListAdapter中:[/size]


else if("lmg".equals(data.type)){
	Drawable drawable=lmgload.loadImage(viewparent,tagpre,data.dataurl,null);
	if(drawable!=null){
		LayoutParams lp=holder.rl_data.getLayoutParams();
		lp.height=itemwidth*drawable.getMinimumHeight()/drawable.getMinimumWidth();
		holder.rl_data.setLayoutParams(lp);
		if(holder.tv_lmgctrl!=null){
			holder.tv_lmgctrl. setVisibility(View.GONE);
			holder.rl_data. removeView(holder.tv_lmgctrl);
		}
		holder.rl_data.setBackground(drawable);
		holder.rl_data.setVisibility(View.VISIBLE);
	}
	else{
		LayoutParams lp=holder.rl_data.getLayoutParams();
		lp.height=itemwidth*data.height/data.width;
		holder.rl_data.setLayoutParams(lp);

		holder.rl_data.setTag(tagpre);
		Drawable pre=imgload.loadImage(viewparent,tagpre,data.preurl,ilcallback);
		holder.rl_data.setBackground(pre);

		if(holder.tv_lmgctrl!=null){
			holder.rl_data.removeView(holder.tv_lmgctrl);
		}

		RelativeLayout.LayoutParams lp1 = new RelativeLayout.LayoutParams(
		LayoutParams.MATCH_PARENT,LayoutParams.WRAP_CONTENT);
		holder.tv_lmgctrl=new TextView(activity);
		holder.tv_lmgctrl.setText("点击查看全图");
		holder.tv_lmgctrl.setGravity(Gravity.CENTER_HORIZONTAL);
		holder.tv_lmgctrl.setTextColor(activity.getResources().getColor(R.color.white_dark));
		holder.tv_lmgctrl.setTextSize(TypedValue.COMPLEX_UNIT_PX,activity.getResources().getDimension(R.dimen.text_level1));
		holder.tv_lmgctrl.setBackgroundResource(R.color.black_normal_88);
		int padding=(int)activity.getResources().getDimension(R.dimen.padding_n);
		holder.tv_lmgctrl.setPadding(padding,padding,padding,padding);
		lp1.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
		holder.tv_lmgctrl.setLayoutParams(lp1);
		holder.tv_lmgctrl.setTag(tagctrllmg);

		holder.rl_data.addView(holder.tv_lmgctrl);

		OnClickListener listener=new OnClickListener() {

			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				v.setOnClickListener(null);
				 ((TextView)v.findViewWithTag(tagctrllmg)).setText("全图加载中...");
				lmgload.loadImage(viewparent,tagpre,data.dataurl,llcallback);
				RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
				holder.pb_load=new ProgressBar(activity,null,android.R.attr.progressBarStyleSmall);
				lp.addRule(RelativeLayout.CENTER_IN_PARENT);
				holder.pb_load.setLayoutParams(lp);
				holder.pb_load.setTag(tagloadlmg);
				holder.rl_data.addView(holder.pb_load);
			}
		};

		holder.rl_data.setOnClickListener(listener);
		holder.rl_data.setVisibility(View.VISIBLE);
	}
}

[size=medium] 图片加载完成的回掉函数：[/size]


private LmageLoadCallback llcallback=new LmageLoadCallback() {
	@SuppressLint("NewApi")
	@Override
	public void onSuccess(Drawable drawable, int tag, View viewParent) {
		// TODO Auto-generated method stub
		if(drawable!=null){
			RelativeLayout rl_data=(RelativeLayout)(viewParent.findViewWithTag(tag));
			if(rl_data!=null){
				LayoutParams lp=rl_data.getLayoutParams();
				lp.height=itemwidth*drawable.getMinimumHeight()/drawable.getMinimumWidth();
				rl_data.setLayoutParams(lp);
				rl_data.setBackground(drawable);
				rl_data.findViewWithTag(tag+1).setVisibility(View.GONE);
				rl_data.findViewWithTag(tag-1).setVisibility(View.GONE);
			}
		}
	}
};

[size=medium] 长图加载的类与图片加载的类相同：[/size]

public class LmageLoad {

	private Context context;

	private Map<String, Drawable> imageMap;
	private ThreadPoolExecutor executor = null;
	BlockingQueue<Runnable> queue =null;

	private String path=Environment.getExternalStorageDirectory()+"/Dp Notes/Cache/LonImage";
	private int threadMaxNum=Runtime.getRuntime().availableProcessors()>1?Runtime.getRuntime().availableProcessors():2;
	private int cacheMaxNum=1;


	@SuppressLint("NewApi")
	public LmageLoad(Context context){
		this.context=context;

		imageMap=new LinkedHashMap<String, Drawable>();
		queue =new ArrayBlockingQueue<Runnable>(this.threadMaxNum);
		executor=new ThreadPoolExecutor(this.threadMaxNum,this.threadMaxNum,1,TimeUnit.MINUTES,queue,new ThreadPoolExecutor.CallerRunsPolicy());

//		File dir=new File(this.path);
//		if(!dir.exists()){
//			dir.mkdirs();
//		}
	}

	public void setcacheMaxNum(int maxNum){
		this.cacheMaxNum=maxNum;
	}

	public Drawable loadImage(final View viewParent,final int viewTag,final String imageUrl,final LmageLoadCallback callback){

		if (imageMap.containsKey(imageUrl)) {
			Drawable drawable=imageMap.get(imageUrl);

			return drawable;
		}
		if(callback==null){
			return null;
		}
//		int index=imageUrl.lastIndexOf("/");
//		index=index>=0?index:0;
//		String filename=imageUrl.substring(index);
//		final String filepath=path+filename+".0";
//		
//		final File mf=new File(filepath);
//		if(mf.exists()){
//			Bitmap bitmap=BitmapFactory.decodeFile(filepath);
//			BitmapDrawable draw=new BitmapDrawable(context.getResources(),bitmap);
//			if(draw!=null){
//				imageMap.put(imageUrl,draw);
//				chackMapSize();
//				return draw;
//			}
//		}
		imageMap.put(imageUrl,null);

		final Handler handler = new Handler() {

			@SuppressLint("HandlerLeak")
			public void handleMessage(Message message) {
				if(callback!=null){
					if(message.what==1){
						callback.onSuccess((Drawable) message.obj,viewTag,viewParent);
					}
				}
			}
		};

		executor.execute(new Runnable() {

			@Override
			public void run() {
				// TODO Auto-generated method stub
				URL url = null;
				InputStream inputStream = null;
				try {
					url = new URL(imageUrl);
					inputStream = url.openStream();
					Drawable drawable = Drawable.createFromStream(inputStream, "src");

					Message message;
					message=handler.obtainMessage(1,drawable);
					handler.sendMessage(message);

					if(drawable!=null){
						imageMap.put(imageUrl,drawable);
					}
					else{
						imageMap.remove(imageUrl);
					}
					chackMapSize();

//					if(drawable!=errorDrawable){
//						try {
//							if(!mf.exists()){
//								try {
//									mf.createNewFile();
//								} catch (IOException e) {
//									// TODO Auto-generated catch block
//									e.printStackTrace();
//								}
//							}
//							FileOutputStream fout=new FileOutputStream(mf);
//							Bitmap bitmap=((BitmapDrawable)drawable).getBitmap();
//							bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fout);
//						} catch (FileNotFoundException e) {
//							// TODO Auto-generated catch block
//							e.printStackTrace();
//						}
//					}

				} catch (Exception e) {
					e.printStackTrace();
				} finally {
					try {
						if (inputStream != null)
							inputStream.close();
					} catch (IOException e) {
						e.printStackTrace();
					}
				}
			}
		});

		return null;
	}

	private void chackMapSize(){

		if(imageMap.size()>cacheMaxNum){
			for(Entry<String, Drawable> m:imageMap.entrySet()){
				imageMap.remove(m.getKey());
				break;
			}
		}

	}

	public interface LmageLoadCallback {
		public void onSuccess(Drawable drawable,int tag,View viewParent);
	}

}

[size=medium] 容易理解，运行：[/size]
[img]http://dl2.iteye.com/upload/attachment/0125/3716/c02b0d71-838c-3b94-a040-ae94f32d0072.gif[/img]
[color=gray][size=medium]注：这是一个.gif动图，ctrl点击图片查看[/size][/color]
[size=medium]
当GIF图片滑动出屏幕时，暂停，需要之前的QRecyclerListener了：[/size]


public ListAdapter(Activity activity,QListView listview){

	…
	listview.setQRecyclerListener(rclistener);
}

private QRecyclerListener rclistener=new QRecyclerListener() {

	@Override
	public void onMovedToScrapHeap(View view) {
		// TODO Auto-generated method stub
		Holder holder=(Holder)view.getTag();
		if(holder!=null&&holder.rl_data!=null){
			if(holder.tv_lmgctrl!=null){
				holder.rl_data.removeView(holder.tv_lmgctrl);
				holder.tv_lmgctrl=null;
			}
			if(holder.giv_data!=null){
				holder.rl_data.removeView(holder.giv_data);
				holder.giv_data=null;
			}
			if(holder.tv_gifctrl!=null){
				holder.rl_data.removeView(holder.tv_gifctrl);
				holder.tv_gifctrl=null;
			}
			if(holder.pb_load!=null){
				holder.rl_data.removeView(holder.pb_load);
				holder.pb_load=null;
			}
		}
	}
};