网络通信之网络图片获取 并显示屏幕上

1.主MainActivity 类代码如下：

public class MainActivity extends Activity {private EditText editText;private ImageView imageView;private static final String TAG="MainActivity";private Button button;private byte []data;private Handler handler = new Handler() { public void handleMessage(Message msg) { switch (msg.what) { case 0: Bitmap bitmap=BitmapFactory.decodeByteArray(data, 0, data.length);imageView.setImageBitmap(bitmap);break; } }; }; @Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);// StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder().detectDiskReads().detectDiskWrites().detectNetwork().penaltyLog().build());// StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder().detectLeakedSqlLiteObjects().detectLeakedClosableObjects().penaltyLog().penaltyDeath().build());setContentView(R.layout.activity_main);editText =(EditText) findViewById(R.id.path);imageView=(ImageView) findViewById(R.id.ImageView); button=(Button) findViewById(R.id.button);button.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {new Thread() { @Override public void run() { // TODO Auto-generated method stub super.run(); String path=editText.getText().toString();try {data=NetTool.getImage(path);} catch (Exception e) {// TODO Auto-generated catch blockToast.makeText(MainActivity.this, "获取图片失败", 1).show();e.printStackTrace();}Message msg = handler.obtainMessage(); msg.what = 0; handler.sendMessage(msg); } }.start(); }});}}

2.NetTool类代码：

public class NetTool {public static byte[] getImage(String path) throws Exception{URL url = new URL(path);HttpURLConnection conn = (HttpURLConnection) url.openConnection();conn.setConnectTimeout(5000);conn.setRequestMethod("GET");if(conn.getResponseCode() == 200){InputStream inStream = conn.getInputStream();return read(inStream);}return null;}public static byte[] read(InputStream inStream) throws Exception{ByteArrayOutputStream outStream = new ByteArrayOutputStream();byte[] buffer = new byte[1024];int len = 0;while( (len = inStream.read(buffer)) != -1){outStream.write(buffer, 0, len);}inStream.close();return outStream.toByteArray();}}

3.activity_main.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" >    <TextView        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:text="@string/path" />    <EditText        android:id="@+id/path"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:text="@string/aa" >    </EditText>    <Button        android:id="@+id/button"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="@string/button" >    </Button>    <ImageView        android:id="@+id/ImageView"        android:layout_width="wrap_content"        android:layout_height="wrap_content" >    </ImageView></LinearLayout>

4.string.xml

<resources>    <string name="app_name">GetPicture</string>    <string name="hello_world">Hello world!</string>    <string name="menu_settings">Settings</string>    <string name="title_activity_main">MainActivity</string>    <string name="path">路径</string>    <string name="button">获取图片</string>    <string name="aa">http://a.hiphotos.baidu.com/image/pic/item/94cad1c8a786c9178f04af6fca3d70cf3bc75765.jpg</string>  </resources>

5.记得在清单文件里加权限：

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

运行结果：