联网查看图片的Demo

1、运行效果图

因为 需要联网，所以要在AndroidManifest.xml中加上联网权限，不然会出现错误。

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

2.目的：通过子线程联网看照片

3.步骤：

4.xml布局：

<RelativeLayout 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: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" ><code class=" hljs xml"><LinearLayout     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" >    <ImageView        android:id="@+id/ivImage"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:layout_gravity="center"        android:layout_weight="1" />    <EditText        android:id="@+id/etImageUrl"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:ems="10"        android:hint="请输入图片的地址"        android:text="http://img01.sogoucdn.com/app/a/100520093/a127e7d8adc3ae1b-0e5fe79cec4c9091-7a53bc8425fe8f98d463766d8ea21a65.jpg" />    <Button        android:id="@+id/btnView"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_gravity="center"        android:background="@drawable/bg"        android:onClick="viewImage"        android:text="浏览" /></LinearLayout></code></RelativeLayout>

5.java代码：

package com.example.demo;<pre name="code" class="java">import java.io.IOException;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import java.text.BreakIterator;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.app.Activity;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.text.TextUtils;import android.view.Menu;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.ImageView;import android.widget.Toast;public class MainActivity extends Activity {Button button;ImageView imageView;EditText ed;private static final int MSG_SUCCESS = 0;// 获取图片成功的标识private static final int MSG_FAILURE = 1;// 获取图片失败的标识@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);findId();}public void findId() {button = (Button) findViewById(R.id.btnView);imageView = (ImageView) findViewById(R.id.ivImage);ed = (EditText) findViewById(R.id.edt);}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}private Handler handler = new Handler(){public void handleMessage(Message msg) {switch (msg.what) {case MSG_SUCCESS:Bitmap bit = (Bitmap) msg.obj;imageView.setImageBitmap(bit);break;default:break;}};};public void viewImage(View view) {final String path = ed.getText().toString();//获取输入的图片路径if (TextUtils.isEmpty(path)) {Toast.makeText(MainActivity.this, " 路径不为空", Toast.LENGTH_SHORT).show();} else {new Thread() {public void run() {URL url;try {url = new URL(path);//发出请求HttpURLConnection connection = (HttpURLConnection) url.openConnection();connection.setRequestMethod("GET");//设置请求方式这里的方式必须为大写connection.setConnectTimeout(5000);//设置超时的时间int code = connection.getResponseCode();//获得状态码if (code == 200) {InputStream is = connection.getInputStream();Bitmap bitmap = BitmapFactory.decodeStream(is);//写入一个bitmap流Message m = new Message();m.what = MSG_SUCCESS;m.obj = bitmap;handler.sendMessage(m);} else {Toast.makeText(MainActivity.this, "打开失败",Toast.LENGTH_SHORT).show();}} catch (MalformedURLException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}};}.start();}}}