Android学习之查看网络图片

在这里小编学习了查看网络图片的小案例,:

初始界面:

点击浏览后,效果如下:

需要注意的是该案例需要获取联网权限,即:

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

具体步骤如下:

1.定义并初始化控件:

private EditText etImageUrl;private ImageView ivImage;

/**控件初始化*/private void init() {ivImage = (ImageView) findViewById(R.id.ivImage);etImageUrl = (EditText) findViewById(R.id.etImageUrl);}

2.建立Handler对象:

private Handler handler = new Handler(){public void handleMessage(android.os.Message msg) {//对接收到的消息进行处理
//            Looper.prepare();switch (msg.what) {case SHOW_IMAGE:Bitmap bitmap = (Bitmap) msg.obj;//将OS流中的Object强制转换为Bitmap对象
                ivImage.setImageBitmap(bitmap);Toast toast = Toast.makeText(MainActivity.this, "图片加载成功", Toast.LENGTH_SHORT);toast.setGravity(0, 0, 100);toast.show();break;default:break;}};};

3.设置显示网络图片的方法:

public void showImage(View view){//若在xml文件中使用onClick（）属性，则其方法格式必须为  方法名（View view）final String path = etImageUrl.getText().toString();if (TextUtils.isEmpty(path)) {Toast.makeText(MainActivity.this, "图片路径不能为空", Toast.LENGTH_SHORT).show();} else {new Thread(){public void run(){//链接服务器，请求获取图片try {URL url = new URL(path);//发出http请求HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();httpURLConnection.setRequestMethod("GET");//设置链接超时时间httpURLConnection.setConnectTimeout(5000);int responsecode = httpURLConnection.getResponseCode();//获取响应码if (responsecode == 200) {InputStream is = httpURLConnection.getInputStream();//获取输入流Bitmap bitmap = BitmapFactory.decodeStream(is);//2.告诉主线程，帮我更新界面，内容是BitmapMessage msg = new Message();msg.what = SHOW_IMAGE;msg.obj = bitmap;handler.sendMessage(msg);}else{Toast toast = Toast.makeText(MainActivity.this, "图片加载失败", Toast.LENGTH_SHORT);toast.setGravity(0, 0, 100);toast.show();}} catch (MalformedURLException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}}.start();//务必启动线程
        }}