网络图片查看器

activity_main.xml代码如下：

共运用了三个控件：ImageView  EditText  Button

  <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:layout_above="@+id/btnView"
        android:layout_alignParentRight="true"
        android:ems="10"
        android:text=""
        android:hint="请输入图片地址" >


        <requestFocus />
    </EditText>


    <Button
        android:id="@+id/btnView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="46dp"
         android:layout_gravity="center"
        android:background="@drawable/b"
        android:onClick="viewImage"
        android:text="浏览" />


</RelativeLayout>

MainActivity.java代码

package bzu.edu.cn.interentimageview1;


import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.logging.Handler;


import android.os.Bundle;
import android.os.Message;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.text.TextUtils;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;
public class MainActivity extends Activity {
private ImageView ivImageShow;
private EditText etUrl;


public static final int SHOWIMAGE=1;
protected static final Context NetImageBrouserActivity = null;

         //在主线程中创建消息处理器
private Handler handler=new Handler(){
public void handleMessage(Message msg){

        //对接收到的新的消息进行处理
switch (msg.what) {
case SHOWIMAGE:
Bitmap bitmap=(Bitmap)msg.obj;
ivImageShow.setImageBitmap(bitmap);
break;


default:
break;
}
};
};
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initViews();
    }
private void initViews(){
etUrl=(EditText)findViewById(R.id.etImageUrl);
ivImageShow=(ImageView)findViewById(R.id.ivImage);
}


    @Override
    public 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;
    }
    
   
    //访问网络，从网络中获取图片
    public void showImage(View view){
    final String path=etUrl.getText().toString();
    if(TextUtils.isEmpty(path)){
    Toast.makeText(this, "图片路径不能为空", Toast.LENGTH_LONG).show();
    }
    else{
    new Thread(){
    public void run(){
    try{
    URL url=new URL(path);
    HttpURLConnection connection=(HttpURLConnection) url.openConnection();
    connection.setRequestMethod("GET");
    connection.setConnectTimeout(5000);
    int responseCode=connection.getResponseCode();
    if(responseCode==200){
    InputStream inputStream=connection.getInputStream();
    Bitmap bitmap=BitmapFactory.decodeStream(inputStream);
    Message message=new Message();
    message.what=SHOWIMAGE;
    message.obj=bitmap;
    handler.sendMessage(message);

   
    }
    //else{
    //Toast.makeText(NetImageBrouserActivity.this, "显示图片失败！",Toast.LENGTH_SHORT).show();   
    }catch(MalformedURLException e){
    e.printStackTrace();
    }catch(IOException e){
    e.printStackTrace();
    }
    };
    }.start();
    }
    }
}