安卓图片查看器笔记

布局文件

<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" >
	<ImageView
	    android:layout_weight="100"
	    android:id="@+id/img_id"
	    android:layout_width="fill_parent"
    	android:layout_height="fill_parent"
	    /> 
	<EditText 
	    android:id="@+id/et"
	    android:text="http://cpro.baidu.com/img/cpro_media_small.png"
	    android:layout_width="fill_parent"
    	android:layout_height="wrap_content"
	    />    
	<Button 
	    android:id="@+id/bt"
	    android:layout_width="fill_parent"
    	android:layout_height="wrap_content"
    	android:text="浏览"
    	android:onClick="getPic"
	    /></LinearLayout>

主文件

package com.look.pic;

import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

import org.apache.http.HttpClientConnection;

import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.text.TextUtils;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;
import android.os.Build;

public class MainActivity extends Activity {
	protected static final int CHANG_UI = 1;
	protected static final int ERROR = 0;
	private ImageView iv;
	private Button bt;
	private EditText et;
	private Handler handler = new Handler(){
		public void handleMessage(android.os.Message msg)
		{
			if (msg.what == CHANG_UI) {
				Bitmap bitmap = (Bitmap) msg.obj;
				iv.setImageBitmap(bitmap);
			} else if(msg.what == ERROR) {
				Toast.makeText(MainActivity.this, "获取图片失败", Toast.LENGTH_SHORT).show();
			}
		}
	};
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		iv = (ImageView) findViewById(R.id.img_id);
		et = (EditText) findViewById(R.id.et);
	}
	
	public void getPic(View view)
	{
		final String path = et.getText().toString().trim();
		if (TextUtils.isEmpty(path)) {
			Toast.makeText(this, "url不能为空", Toast.LENGTH_SHORT);
		} else {
			new Thread(){
				public void run()
				{
					try {
						URL url = new URL(path);
						HttpURLConnection conn = (HttpURLConnection) url.openConnection();
						conn.setRequestMethod("GET");
						conn.setConnectTimeout(5000);
						conn.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.135 Safari/537.36");
						int code = conn.getResponseCode();
						if (code == 200) {
							InputStream is = conn.getInputStream();
							Bitmap bit = BitmapFactory.decodeStream(is);
							Message msg = new Message();
							msg.what = CHANG_UI;
							msg.obj = bit;
							handler.sendMessage(msg);
						} else {
							Message msg = new Message();
							msg.what = ERROR;
							handler.sendMessage(msg);
						}
					} catch (Exception e) {
						e.printStackTrace();
						Message msg = new Message();
						msg.what = ERROR;
						handler.sendMessage(msg);
					}
				}
			}.start();
		}
	}
}

清单文件增加权限

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