一.activity_main.xml佈局檔案
<LinearLayout 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"
    android:orientation="vertical"
    tools:context="cn.bzu.edu.imageviewdemo1.MainActivity">


    <ImageView
        android:id
 
="@+id/iv"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_weight="1"
        />
    <EditText
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text=""（加入網址）
        android:hint="請輸入圖片路徑"
 

        android:id="@+id/et_path"
        android:maxLines="1"
        />
    <Button
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:onClick="click"
        android:text="瀏覽"/>



</LinearLayout>

二.MainActivity介面互動程式碼

package cn.bzu.edu.imageviewdemo1;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.media.Image;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Log;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;

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

public class MainActivity extends AppCompatActivity {
    protected static final int CHANGE_UI = 1;
    protected static final int ERROR = 2;
    private EditText et_path;
    private ImageView iv;

    private Handler handler = new Handler() {
        public void handleMessage(android.os.Message msg) {
            if (msg.what == CHANGE_UI) {
                Bitmap bitmap = (Bitmap) msg.obj;
                iv.setImageBitmap(bitmap);
            } else if (msg.what == ERROR) {
                Toast.makeText(MainActivity.this, "顯示圖片錯誤", 0).show();
            }
        };


    };


    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        et_path = (EditText) findViewById(R.id.et_path);
        iv = (ImageView) findViewById(R.id.iv);
    }

    public void click(View view) {
        final String path = et_path.getText().toString().trim();
        if (TextUtils.isEmpty(path)) {
            Toast.makeText(this, "圖片路徑不能為空", Toast.LENGTH_SHORT).show();
        } else {
            new Thread() {
                public void run() {
                    try {
                        URL url = new URL(path);
                        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                        conn.setRequestMethod("GET");
                        conn.setConnectTimeout(5000);
                        int code = conn.getResponseCode();
                        Log.d("MainActivity",code+"");
                        if (code == 200) {
                            InputStream is = conn.getInputStream();
                            Bitmap bitmap = BitmapFactory.decodeStream(is);
                            Message msg = new Message();
                            msg.what = CHANGE_UI;
                            msg.obj=bitmap;
                            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();


        }
    }
}

三、AndriodManifest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="cn.bzu.edu.imageviewdemo1">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
    <uses-permission android:name="android.permission.INTERNET"></uses-permission>

</manifest>