标签:android style blog color io os ar strong sp
android中获取网络图片是一件耗时的操作,如果直接获取有可能会出现应用程序无响应(ANR:Application Not Responding)对话框的情况。对于这种情况,一般的方法就是耗时操作用线程来实现。下面列三种获取url图片的方法:
1.直接获取:(容易:ANR,不建议)
mImageView = (ImageView)this.findViewById(R.id.imageThreadConcept) ; Drawable drawable = loadImageFromNetwork(IMAGE_URL); mImageView.setImageDrawable(drawable) ;
公用方法: private Drawable loadImageFromNetwork(String imageUrl) { Drawable drawable = null; try { // 可以在这里通过文件名来判断,是否本地有此图片 drawable = Drawable.createFromStream( new URL(imageUrl).openStream(), "image.jpg"); } catch (IOException e) { Log.d("test", e.getMessage()); } if (drawable == null) { Log.d("test", "null drawable"); } else { Log.d("test", "not null drawable"); } return drawable ; }
2. 后台线程获取url图片:
mImageView = (ImageView)this.findViewById(R.id.imageThreadConcept) ; new Thread(new Runnable(){ Drawable drawable = loadImageFromNetwork(IMAGE_URL); @Override public void run() { // post() 特别关键,就是到UI主线程去更新图片 mImageView.post(new Runnable(){ @Override public void run() { // TODO Auto-generated method stub mImageView.setImageDrawable(drawable) ; }}) ; } }).start() ;
3.AsyncTask获取url图片
mImageView = (ImageView)this.findViewById(R.id.imageThreadConcept) ; new DownloadImageTask().execute(IMAGE_URL) ; private class DownloadImageTask extends AsyncTask<String, Void, Drawable> { protected Drawable doInBackground(String... urls) { return loadImageFromNetwork(urls[0]); } protected void onPostExecute(Drawable result) { mImageView.setImageDrawable(result); } }
标签:android style blog color io os ar strong sp
原文地址:http://www.cnblogs.com/zhanganju/p/4053535.html