android查看网络图片的实现方法

package com.example.www.checkimage;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.os.Bundle;import android.os.Handler;import android.os.Message;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.InputStream;import java.net.HttpURLConnection;import java.net.URL;public class MainActivity extends AppCompatActivity { private EditText mPt_url; private ImageView mIv_show; private Handler mHandler = new Handler(){ @Override public void handleMessage(Message msg) { if(msg.what == 1){ Bitmap bitmap = (Bitmap) msg.obj; mIv_show.setImageBitmap(bitmap); Toast.makeText(getApplicationContext(), "图片展示成功", Toast.LENGTH_LONG).show(); } } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mPt_url = (EditText) findViewById(R.id.pt_url); mIv_show = (ImageView) findViewById(R.id.imageCon); } public void checkImage(View v) { new Thread(){ @Override public void run() { try {  String path = mPt_url.getText().toString().trim();  URL url = new URL(path);  HttpURLConnection conn = (HttpURLConnection) url.openConnection();  conn.setRequestMethod("GET");  conn.setConnectTimeout(5000);  int responseCode = conn.getResponseCode();  if(responseCode == 200) {  InputStream is = conn.getInputStream();  Bitmap bitmap = BitmapFactory.decodeStream(is);  Message msg = Message.obtain(); // 创建 消息  msg.obj = bitmap;  msg.what = 1;  mHandler.sendMessage(msg);  } } catch (Exception e) {  e.printStackTrace(); } } }.start(); }}

<?xml version="1.0" encoding="utf-8"?><android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <EditText android:id="@+id/pt_url" android:layout_width="368dp" android:layout_height="wrap_content" android:layout_marginStart="8dp" android:layout_marginTop="8dp" android:layout_marginEnd="8dp" android:ems="10" android:hint="请输入与图片地址" android:inputType="textPersonName" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" /> <Button android:id="@+id/button" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginStart="8dp" android:layout_marginTop="8dp" android:layout_marginEnd="8dp" android:text="Button" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.0" app:layout_constraintStart_toStartOf="parent" android:onClick="checkImage" app:layout_constraintTop_toBottomOf="@+id/pt_url" /> <ImageView android:id="@+id/imageCon" android:layout_width="0dp" android:layout_height="0dp" android:layout_marginStart="8dp" android:layout_marginTop="8dp" android:layout_marginEnd="8dp" android:layout_marginBottom="8dp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/button" app:srcCompat="@mipmap/ic_launcher" /></android.support.constraint.ConstraintLayout>

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.www.checkimage"> <uses-permission android:name="android.permission.INTERNET"/> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round" 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></manifest>