佈局檔案如下：

<LinearLayout 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"
android:orientation="vertical"
tools:context=".MainActivity">
    <EditText
android:id="@+id/et_main_netpass"
 
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:hint="請輸入地址"
android:text="https://www.baidu.com/img/bd_logo1.png"/>
    <Button
android:id="@+id/bt_main_see"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="檢視圖片"/>
    <ImageView
 
android:id="@+id/iv_main_showimage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</LinearLayout>

在AndroidManifest檔案中新增網路訪問許可權;

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

實現程式碼如下：

package cn.test.ning.netimageview;
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.text.TextUtils;
import android.util.Base64;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
public class MainActivity extends Activity {
    private static final int UPDATE = 0;
    private EditText et_main_netpass;
    private ImageView iv_main_showimage;
    private Button bt_main_see;
    private Handler mHandler = new Handler() {
        @Override
public void handleMessage(Message msg) {
            switch (msg.what) {
                case UPDATE: {
                    Bitmap bitmap = (Bitmap) msg.obj;
iv_main_showimage.setImageBitmap(bitmap);
                    break;
}
                default:
                    break;
}
        }
    };
    private void initView() {
        setContentView(R.layout.activity_main);
et_main_netpass = (EditText) this.findViewById(R.id.et_main_netpass);
iv_main_showimage = (ImageView) this.findViewById(R.id.iv_main_showimage);
bt_main_see = (Button) this.findViewById(R.id.bt_main_see);
}

    @Override
protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
initView();
initEvent();
}

    private void initEvent() {
        bt_main_see.setOnClickListener(new View.OnClickListener() {
            @Override
public void onClick(View v) {
                final String path = et_main_netpass.getText().toString().trim();
                if (TextUtils.isEmpty(path)) {//檢測路徑是否合法
Toast.makeText(MainActivity.this, "路徑為空", Toast.LENGTH_SHORT).show();
                    return;
} else {
                    //從快取中取出圖片，並顯示在介面中
File file = new File(getCacheDir(), Base64.encodeToString(path.getBytes(), Base64.DEFAULT));
                    if (file.exists() && file.length() > 0) {
                        Bitmap bitmap = BitmapFactory.decodeFile(file.getAbsolutePath());
iv_main_showimage.setImageBitmap(bitmap);
Toast.makeText(MainActivity.this, "get image form cache", Toast.LENGTH_SHORT).show();
} else {
                        new Thread() {
                            @Override
public void run() {//在子執行緒中訪問網路，並快取圖片資源
try {
                                    //申明訪問的路徑
URL url = new URL(path);
//通過路徑，得到連結
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
//設定連結方式
connection.setRequestMethod("GET");
//設定連結超時時間
connection.setConnectTimeout(5000);
//設定寫入超時時間
connection.setReadTimeout(5000);
//獲取請求響應碼
int code = connection.getResponseCode();
                                    if (200 == code) {
                                        //獲取請求返回的位元組流
InputStream inputStream = connection.getInputStream();
File file = new File(MainActivity.this.getCacheDir(), Base64.encodeToString(path.getBytes(), Base64.DEFAULT));
                                        byte[] buffer = new byte[1024];
                                        int len = 0;
FileOutputStream fos = new FileOutputStream(file);
                                        while ((len = inputStream.read(buffer)) > 0) {
                                            fos.write(buffer, 0, len);
}
                                        fos.close();
inputStream.close();
Bitmap bitmap = BitmapFactory.decodeFile(file.getAbsolutePath());
//Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
                                        //iv_main_showimage.setImageBitmap(bitmap);
Message message = Message.obtain();
message.what = UPDATE;
message.obj = bitmap;
mHandler.sendMessage(message);
} else {
                                        Toast.makeText(MainActivity.this, "reqeust is fail", Toast.LENGTH_SHORT).show();
}
                                } catch (MalformedURLException e) {
                                    e.printStackTrace();
} catch (IOException e) {


                                }
                            }
                        }.start();
}

                }

            }
        });
}

}