Android学习第十七天----从网络上获取图片

<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"
    tools:context=".MainActivity" >

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="25dp"
        android:layout_marginTop="98dp"
        android:text="Button" />

    <EditText
        android:id="@+id/editText1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/button1"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="27dp"
        android:layout_marginTop="16dp"
        android:ems="10" 
        android:text="http://wenwen.soso.com/p/20101012/20101012083824-923841609.jpg">
    </EditText>

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/button1"
        android:layout_marginTop="88dp"
        android:src="@drawable/ic_launcher" />

</RelativeLayout>

在页面中设置一个按钮，然后点击，将图片显示在页面中

package com.example.service;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;

public class ImageService {
    public static byte[] getImage(String path) {
//    Bitmap bitmap = null;
    InputStream is = null;
    try {
        URL url = new URL(path);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setReadTimeout(5 * 1000);
        conn.setRequestMethod("GET");
        if (conn.getResponseCode() == 200) {
        is = conn.getInputStream();
//        bitmap = BitmapFactory.decodeStream(is);
        }
    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return getImageByte(is);
    }
    public static byte[] getImageByte(InputStream is)
    {
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    byte[] b = new byte[1024];
    int len = 0;
    try {
        while((len = is.read(b))!=-1)
        {
            baos.write(b, 0, len);
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
    return baos.toByteArray();
    }
}

mainActivity中

package com.example.httpimage;

import com.example.service.ImageService;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;

public class MainActivity extends Activity {
    private Handler handler = new Handler() {
    @Override
    public void handleMessage(Message msg) {
        if (msg.what == 100) {
        image.setImageBitmap((Bitmap) msg.obj);
        }
    }
    };
    private Button mButton;
    private ImageView image;
    private EditText edit;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mButton = (Button) findViewById(R.id.button1);
    image = (ImageView) findViewById(R.id.imageView1);
    edit = (EditText) findViewById(R.id.editText1);

    mButton.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
        new Thread(new Runnable() {

            @Override
            public void run() {
            Message msg = new Message();
            msg.what = 100;
            BitmapFactory.Options options = new BitmapFactory.Options();
            options.inSampleSize = 2;
            byte[] b = ImageService.getImage(edit.getText()
                .toString());
            msg.obj = BitmapFactory.decodeByteArray(b, 0, b.length,options);
            handler.sendMessage(msg);
            }
        }).start();
        }
    });

    }
}