Android获取网络图片应用示例

1、养成好习惯，配置字符串资源文件 strings.xml

 

<?xml version="1.0" encoding="utf-8"?>

<resources>

    <string name="app_name">网络图片查看器</string>

    <string name="action_settings">Settings</string>

    <string name="hello_world">Hello world!</string>

	<string name="imgpath">输入图片地址：</string>

	<string name="getBtn">获取图片</string>

	<string name="error">获取图片失败</string>

</resources>

2、布局文件，使用垂直布局

 

 

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:orientation="vertical"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    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="fill_parent"

        android:layout_height="wrap_content"

        android:text="@string/imgpath"

        />

	

    <EditText android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:id="@+id/imgpathInput"

        android:text="http://avatar.csdn.net/B/E/7/1_gaotong2055.jpg"

        android:inputType="text" />

    <Button 

         android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="@string/getBtn"

        android:id="@+id/getBtn"

        />

    <ImageView 

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:id="@+id/imgView"

        />

</LinearLayout>

3、编写代码

 

这里为了方便看代码，都写在一个类里面了。

可以把里面的静态方法单独拆分出来，写在一个工具类中，结构更好。

 

public class MainActivity extends Activity implements OnClickListener {

	private EditText pathText;

	private ImageView imageView;



	@Override

	protected void onCreate(Bundle savedInstanceState) {

		super.onCreate(savedInstanceState);

		setContentView(R.layout.activity_main);

		pathText = (EditText) this.findViewById(R.id.imgpathInput);

		imageView = (ImageView) this.findViewById(R.id.imgView);

		Button button = (Button) this.findViewById(R.id.getBtn);

		button.setOnClickListener(this);

	}



	@Override

	public boolean onCreateOptionsMenu(Menu menu) {

		getMenuInflater().inflate(R.menu.main, menu);

		return true;

	}



	@Override

	public void onClick(View v) {

		String path = pathText.getText().toString();

		byte[] data = null;

		try {

			data = getImgData(path);

		} catch (Exception e) {

			e.printStackTrace();

			Toast.makeText(this, R.string.error, 1).show();

		}

		Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);

		imageView.setImageBitmap(bitmap);

	}



	public static byte[] getImgData(String path) throws Exception {



		URL url = new URL(path);

		HttpURLConnection conn = (HttpURLConnection) url.openConnection();

		conn.setConnectTimeout(5000);// 超时时间5秒

		conn.setRequestMethod("GET");

		if (conn.getResponseCode() == 200) {

			InputStream in = conn.getInputStream();

			return read(in);

		} else {

			Log.d("tong.getImg", "服务器无响应");

		}



		return null;

	}



	/**

	 * 从一个输入流中读取数据，并返回

	 * 

	 * @param in

	 * @return byte[] 数据

	 * @throws IOException

	 */

	public static byte[] read(InputStream in) throws IOException {

		// 开辟一个内存的区域，以写入数据

		ByteArrayOutputStream outStream = new ByteArrayOutputStream();

		byte[] buffer = new byte[10240];

		int len = 0;

		while ((len = in.read(buffer)) != -1) {

			outStream.write(buffer, 0, len);

		}

		outStream.close();



		return outStream.toByteArray(); // 返回内存中的数据

	}



}

 

 

运行效果：