Android图片显示之通过handler机制实现数据通讯

来源：互联网发布：已备案域名如何注销编辑：程序博客网时间：2024/05/29 13:48

public class Test extends Activity {    private ImageView img;    private Handler handlers;    private String url="http://changsha.ejoooo.com/api/jianlijjlists.aspx?userid=544";    private String imgUrl="http://p3.so.qhimg.com/t018124199aa674a553.jpg";    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        this.setContentView(R.layout.data_test);        img = (ImageView) findViewById(R.id.img);        displayImg(imgUrl);        //handler线程通讯机制        handlers = new Handler(){            @Override            public void handleMessage(Message msg) {                super.handleMessage(msg);                if(msg.what == 0x001){                    byte[] b = (byte[]) msg.obj;                    Bitmap bitmap = BitmapFactory.decodeByteArray(b,0,b.length);                    img.setImageBitmap(bitmap);                }            }        };    }

    //显示图片的方法    public void displayImg(final String urls){        new Thread(new Runnable() {            @Override            public void run() {                try {                    int array_len = new URL(urls).openConnection().getContentLength();//图片长度                    InputStream is = new URL(urls).openConnection().getInputStream();                    byte[] all = new byte[array_len];//储存图片的总字节数组                    int p=0;//指针                    byte[] b = new byte[1024];                    int len = is.read(b, 0, b.length);//每次读到的数组长度                    while (len>0){                        int i=0;                        for(;i<len;i++){                            all[i+p] = b[i];//将每次读到的字节储存到all数组                        }                        len = is.read(b,0,b.length);                        p+= i;//指针后移                    }                    is.close();                    //通过handler机制实现线程间通讯（子线程负责获取数据，主程序负责改变UI界面）                    Message message = handlers.obtainMessage(0x001);                    message.obj=all;                    handlers.sendMessage(message);                } catch (IOException e) {                    e.printStackTrace();                }            }        }).start();    }}

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