和注册 Introduction.class 文件
- <uses-permission android:name="android.permission.INTERNET" />
- <activity android:name=".Introduction"></activity>
- <?xml version="1.0" encoding="utf-8"?>
- <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"
- android:gravity="center"
- tools:context="com.example.pj.download.MainActivity">
- <ImageView
- android:id="@+id/img"
- android:layout_width="match_parent"
- android:layout_height="wrap_content" />
- <Button
- android:id="@+id/btn_picture"
- android:layout_width="match_parent"
- android:layout_height="wrap_content"
- android:layout_marginTop="20dp"
- android:text="图片下载"
- android:textSize="30sp"
- android:gravity="center"/>
- <Button
- android:id="@+id/btn_introduction"
- android:layout_width="match_parent"
- android:layout_height="wrap_content"
- android:layout_marginTop="20dp"
- android:text="图书简介"
- android:textSize="30sp"
- android:gravity="center"/>
- </LinearLayout>
- package com.example.pj.download;
- import android.content.Intent;
- import android.graphics.Bitmap;
- import android.graphics.BitmapFactory;
- import android.os.Handler;
- import android.os.Message;
- import android.support.v7.app.AppCompatActivity;
- import android.os.Bundle;
- import android.view.View;
- import android.widget.Button;
- import android.widget.ImageView;
- import java.io.IOException;
- import java.io.InputStream;
- import java.net.HttpURLConnection;
- import java.net.URL;
- public class MainActivity extends AppCompatActivity {
- private Button btn_p;
- private Button btn_i;
- private ImageView img;
- Handler handler = new Handler() {
- public void handleMessage(android.os.Message msg) {
- img.setImageBitmap((Bitmap) msg.obj);
- }
- };
- public Bitmap getInternetPicture(String UrlPath) {
- HttpURLConnection httpURLConnection = null;
- Bitmap bm = null;
- try {
- URL url = new URL(UrlPath);
- httpURLConnection = (HttpURLConnection) url.openConnection();
- httpURLConnection.setRequestMethod("GET");
- httpURLConnection.setReadTimeout(5000);
- httpURLConnection.setConnectTimeout(10000);
- int responseCode = httpURLConnection.getResponseCode();
- if (responseCode == 200) {
- InputStream is = httpURLConnection.getInputStream();
- bm = BitmapFactory.decodeStream(is);
- }
- } catch (IOException e) {
- e.printStackTrace();
- } finally {
- if (httpURLConnection != null) {
- httpURLConnection.disconnect();
- }
- }
- return bm;
- }
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.activity_main);
- img = (ImageView) findViewById(R.id.img);
- btn_p = (Button) findViewById(R.id.btn_picture);
- btn_i = (Button) findViewById(R.id.btn_introduction);
- btn_p.setOnClickListener(new View.OnClickListener() {
- @Override
- public void onClick(View view) {
- new Thread(new Runnable() {
- @Override
- public void run() {
- String URL = "https://img3.doubanio.com/lpic/s1076932.jpg";
- Bitmap bm = getInternetPicture(URL);
- Message msg = new Message();
- msg.obj = bm;
- handler.sendMessage(msg);
- }
- }).start();
- }
- });
- btn_i.setOnClickListener(new View.OnClickListener() {
- @Override
- public void onClick(View v) {
- Intent intent = new Intent(MainActivity.this,Introduction.class);
- startActivity(intent);
- }
- });
- }
- }
- <?xml version="1.0" encoding="utf-8"?>
- <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
- android:layout_width="match_parent"
- android:layout_height="match_parent"
- android:orientation="vertical">
- <TextView
- android:layout_width="match_parent"
- android:layout_height="wrap_content"
- android:text="
- <Button
- android:id="@+id/btn_return"
- android:layout_width="match_parent"
- android:layout_height="wrap_content"
- android:text="返回"
- android:layout_marginTop="20dp"/>
- </LinearLayout>
- package com.example.pj.download;
- import android.content.Intent;
- import android.os.Bundle;
- import android.support.v7.app.AppCompatActivity;
- import android.view.View;
- import android.widget.Button;
- /**
- * Created by pj on 2017/3/28.
- */
- public class Introduction extends AppCompatActivity {
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.introduction);
- Button btn_r = (Button)findViewById(R.id.btn_return);
- btn_r.setOnClickListener(new View.OnClickListener() {
- @Override
- public void onClick(View v) {
- Intent intent = new Intent(Introduction.this,MainActivity.class);
- startActivity(intent);
- }
- });
- }
- }
来源: http://www.bubuko.com/infodetail-1999778.html