android网络图片查看器简单实现代码

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:tools="http://schemas.android.com/tools"  android:id="@+id/activity_main"  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="com.itheima74.internetpicturelook.MainActivity">  <EditText    android:id="@+id/et_url"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:layout_alignParentLeft="true"    android:layout_alignParentStart="true"    android:layout_alignParentTop="true"    android:hint="请输入图片网址"    android:inputType="textUri"    android:text="http://b.hiphotos.baidu.com/image/pic/item/d009b3de9c82d15825ffd75c840a19d8bd3e42da.jpg" />  <Button    android:id="@+id/bt_look"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:layout_below="@+id/et_url"    android:text="查看图片" />  <ScrollView    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_below="@+id/bt_look"    android:layout_centerHorizontal="true">    <ImageView      android:id="@+id/iv"      android:layout_width="wrap_content"      android:layout_height="wrap_content" />  </ScrollView></RelativeLayout>

package com.itheima74.internetpicturelook;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.EditText;import android.widget.ImageView;import android.widget.Toast;import java.io.IOException;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;public class MainActivity extends AppCompatActivity {  private EditText et_url;  private ImageView iv;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    et_url = (EditText) findViewById(R.id.et_url);    iv = (ImageView) findViewById(R.id.iv);    findViewById(R.id.bt_look).setOnClickListener(new View.OnClickListener() {      @Override      public void onClick(View v) {        String path = et_url.getText().toString().trim();        if (path.isEmpty()) {          Toast.makeText(MainActivity.this, "请输入图片网址", Toast.LENGTH_SHORT).show();        } else {          //开启子线程去网络下载图片          downLoadPicture(path);        }      }      private void downLoadPicture(final String path) {        // 子线程请求网络        new Thread() {          @Override          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();                final Bitmap bitmap = BitmapFactory.decodeStream(inputStream);                // 主线程更新UI                runOnUiThread(new Runnable() {                  @Override                  public void run() {                    iv.setImageBitmap(bitmap);                  }                });              }            } catch (IOException e) {              e.printStackTrace();            }          }        }.start();      }    });  }}