最简单 网络获取图片

//添加权限

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

//设置的全局变量

private Button button;private ImageView imageView;String url="http://pic39.nipic.com/20140226/18071023_164300608000_2.jpg";Handler handler=new Handler(){    @Override    public void handleMessage(Message msg) {        super.handleMessage(msg);        imageView.setImageBitmap((Bitmap)msg.obj);    }};

//正式内容

button = (Button) findViewById(R.id.button);imageView = (ImageView) findViewById(R.id.imageView);button.setOnClickListener(new View.OnClickListener() {    @Override    public void onClick(View v) {        new Thread(new Runnable() {            @Override            public void run() {                Bitmap jiexi = jiexi(url);                Message message=new Message();                message.obj=jiexi;                handler.sendMessage(message);            }        }).start();    }});//方法
public Bitmap jiexi(String urlstring){        Bitmap bitmap=null;    try {        //Android studio 选中 Ctrl+Alt+T(try catch)        URL url1= new URL(urlstring);        HttpURLConnection urlConnection = (HttpURLConnection) url1.openConnection();              urlConnection.setReadTimeout(5000);        urlConnection.setConnectTimeout(5000);        urlConnection.connect();        if (urlConnection.getResponseCode()==200){            InputStream inputStream = urlConnection.getInputStream();             bitmap = BitmapFactory.decodeStream(inputStream);        }else{            bitmap=null;        }    } catch (MalformedURLException e) {        e.printStackTrace();    } catch (IOException e) {        e.printStackTrace();    }    return  bitmap;}