Android从网络中获取图片

来源：互联网发布：单片机开发板能做什么编辑：程序博客网时间：2024/04/26 06:38

Android从网络中获取图片

1. 首先要在AndroidManifest.xml文件中添加访问网络的权限：

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

2. 接着是界面：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context=".MainActivity" >    <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="网络图片地址" />    <EditText         android:id="@+id/edit_address"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="http://a.hiphotos.baidu.com/image/pic/item/b3b7d0a20cf431adb35c8e304936acaf2edd9829.jpg"        />    <Button         android:id="@+id/btn_get"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="获取图片"        />    <ImageView        android:id="@+id/imageview"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        /></LinearLayout>

3. 然后是Activity中的方法：

public class MainActivity extends Activity {    private Button btn_get;    private EditText edit_address;    private ImageView imageview;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        /*android 2.3版本之后不允许在主线程中进行http请求防止界面假死，此法不推荐使用。         * 建议方法为新建线程操作。         */        if (android.os.Build.VERSION.SDK_INT > 9) {            StrictMode.ThreadPolicy policy =                     new StrictMode.ThreadPolicy.Builder().permitAll().build();            StrictMode.setThreadPolicy(policy);        }        btn_get = (Button) findViewById(R.id.btn_get);        edit_address = (EditText) findViewById(R.id.edit_address);        imageview = (ImageView) findViewById(R.id.imageview);        btn_get.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View v) {                // TODO Auto-generated method stub                String path = edit_address.getText().toString();                ImageService imageService = new ImageService();                try {                    byte[] data = imageService.getImage(path);                    Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);                    imageview.setImageBitmap(bitmap);                } catch (Exception e) {                    Toast.makeText(MainActivity.this, "获取失败", 1000).show();                    Log.e("ImageError", e.toString());                }            }        });    }    public class ImageService {        public byte[] getImage(String path) throws Exception{            URL url = new URL(path);            HttpURLConnection conn = (HttpURLConnection)url.openConnection();            conn.setRequestMethod("GET");            conn.setConnectTimeout(5 * 1000);            InputStream inputStream = conn.getInputStream();//通过输入流获取图片数据            byte[] data = readInputStream(inputStream);//得到图片的二进制数据            return data;        }        public byte[] readInputStream(InputStream inputStream) throws Exception {            ByteArrayOutputStream outputStream = new ByteArrayOutputStream();            byte[] buffer = new byte[1024];            int len = 0;            while((len = inputStream.read(buffer)) != -1) {                outputStream.write(buffer, 0, len);//写到内存            }            inputStream.close();            return outputStream.toByteArray();        }    }}

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