影视分享App（二）

一、开发进度二

第二步主要实现在首页页面左右滑动功能，以及搭建图片及数据访问框架来在页面在Top250页面上显示实现网站图片。

1、左右滑动功能

新建布局文件one_child_fragment_layout.layout以及首页的子fragment OneChildFragment.java

<?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">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="第一个Fragment的子Fragment" />

</LinearLayout>

package com.example.yingshifenxiang.fragment;


import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import androidx.fragment.app.Fragment;

import com.example.yingshifenxiang.R;

public class OneChildFragment extends Fragment {


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        return inflater.inflate(R.layout.one_child_fragment_layout, null);
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

    }
}

重写OneFragment.java

package com.example.yingshifenxiang.fragment;

import android.view.View;
import android.view.LayoutInflater;
import android.view.ViewGroup;
import android.os.Bundle;

import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentPagerAdapter;
import androidx.viewpager.widget.ViewPager;

import com.example.yingshifenxiang.R;
import com.google.android.material.tabs.TabLayout;


public class OneFragment extends Fragment {
    private TabLayout tabLayout;
    private ViewPager viewPager;


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        return inflater.inflate(R.layout.one_fragment_layout, null);
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);


        tabLayout=(TabLayout)view.findViewById(R.id.tabLayout);
        viewPager=(ViewPager)view.findViewById(R.id.viewPager);
        MyPagerAdapter myPagerAdapter = new MyPagerAdapter(this.getChildFragmentManager());
        viewPager.setAdapter(myPagerAdapter);
        tabLayout.setupWithViewPager(viewPager);

    }

    String[] TITLES = {"正在热映", "即将上映", "北美票房"};
    class MyPagerAdapter extends FragmentPagerAdapter {

        public MyPagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int position) {
            if(position==0){

            }
            if(position==1){

            }
            if(position==2){

            }
            return new OneChildFragment();
        }

        @Override
        public int getCount() {
            return TITLES.length;
        }

        @Nullable
        @Override
        public CharSequence getPageTitle(int position) {
            return TITLES[position];
        }
    }

}

二、搭建图片及数据访问框架来在页面在Top250页面上显示实现网站图片

在AndroidManifest.xml以及build.gradle中添加部署及下载第三方库

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.example.yingshifenxiang" >
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"
        tools:ignore="ProtectedPermissions"/>
    <application
        android:name=".MyApplication"
        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"
            android:label="@string/app_name"
            android:theme="@style/AppTheme.NoActionBar" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

</manifest>

apply plugin: 'com.android.application'

android {
    compileSdkVersion 29
    buildToolsVersion "29.0.3"

    defaultConfig {
        applicationId "com.example.yingshifenxiang"
        minSdkVersion 15
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }

}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])

    implementation 'androidx.appcompat:appcompat:1.1.0'
    implementation 'androidx.legacy:legacy-support-v4:1.0.0'
    implementation 'com.google.android.material:material:1.1.0'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    implementation 'androidx.navigation:navigation-fragment:2.2.1'
    implementation 'androidx.navigation:navigation-ui:2.2.1'
    implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0'
    implementation 'com.nostra13.universalimageloader:universal-image-loader:1.9.3'
    implementation 'com.mcxiaoke.volley:library:1.0.19'
    implementation 'com.google.code.gson:gson:2.8.5'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
}

在这里遇到了一个小问题，下载库失败，通过在项目build.gradle中加入镜像解决

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    
    repositories {
        maven{ url 'https://maven.aliyun.com/repository/google/'}
        maven{ url 'https://maven.aliyun.com/repository/jcenter/'}
        google()
        jcenter()
        
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.6.1'
        

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        maven{ url 'https://maven.aliyun.com/repository/google/'}
        maven{ url 'https://maven.aliyun.com/repository/jcenter/'}
        google()
        jcenter()
        
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

准备工作已完成，接下来就是具体的代码了

新建MyApplication.java这个java文件是一套模板代码，在获取图片时使用

package com.example.yingshifenxiang;


import android.app.Application;
import android.content.Context;

import com.android.volley.DefaultRetryPolicy;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.toolbox.Volley;
import com.nostra13.universalimageloader.cache.disc.naming.Md5FileNameGenerator;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
import com.nostra13.universalimageloader.core.assist.ImageScaleType;
import com.nostra13.universalimageloader.core.assist.QueueProcessingType;

public class MyApplication extends Application {
    //ImageLoader显示图片过程中的参数
    private static DisplayImageOptions mLoaderOptions;
    //Volley网络请求的队列对象
    private static RequestQueue mQueue;


    @Override
    public void onCreate() {
        super.onCreate();
        //初始化ImageLoader
        initImageLoader(getApplicationContext());
        //初始化Volley的队列对象
        mQueue = Volley.newRequestQueue(getApplicationContext());
    }

    public static void initImageLoader(Context context) {
        //初始化一个ImageLoaderConfiguration配置对象
        ImageLoaderConfiguration config = new ImageLoaderConfiguration.
                Builder(context).
                denyCacheImageMultipleSizesInMemory().
                threadPriority(Thread.NORM_PRIORITY - 2).
                diskCacheFileNameGenerator(new Md5FileNameGenerator()).
                tasksProcessingOrder(QueueProcessingType.FIFO).
                build();
        //用ImageLoaderConfiguration配置对象完成ImageLoader的初始化，单例
        ImageLoader.getInstance().init(config);
        //示图片过程中的参数
        mLoaderOptions = new DisplayImageOptions.Builder().
                showImageOnLoading(R.drawable.no_image).//正加载，显示no_image
                showImageOnFail(R.drawable.no_image).//加载失败时
                showImageForEmptyUri(R.drawable.no_image).//加载的Uri为空
                imageScaleType(ImageScaleType.EXACTLY_STRETCHED).
                cacheInMemory(true).//是否进行缓冲
                cacheOnDisk(true).
                considerExifParams(true).
                build();
    }



    public static RequestQueue getHttpQueue() {
        return mQueue;
    }

    public static DisplayImageOptions getLoaderOptions() {
        return mLoaderOptions;
    }
    //Volley请求，传入消息编号Tag。将request请求放入队列中缓存
    public static void addRequest(Request request, Object tag) {
        request.setTag(tag);
        request.setRetryPolicy(new DefaultRetryPolicy(10000,
                DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
                DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
        mQueue.add(request);
    }
    // 通过消息编号在队列中删除请求
    public static void removeRequest(Object tag) {
        mQueue.cancelAll(tag);
    }

}

重写three_fragment_layout

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="three"/>
    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/imageView"/>

</LinearLayout>

重写ThreeFragment.java

package com.example.yingshifenxiang.fragment;

import android.os.Bundle;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;

import androidx.fragment.app.Fragment;

import com.example.yingshifenxiang.MyApplication;
import com.example.yingshifenxiang.R;
import com.nostra13.universalimageloader.core.ImageLoader;


public class ThreeFragment extends Fragment {


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        return inflater.inflate(R.layout.three_fragment_layout, null);
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        ImageView iv=(ImageView)view.findViewById(R.id.imageView);
        ImageLoader.getInstance().displayImage("http://a3.att.hudong.com/14/75/01300000164186121366756803686.jpg",
                iv, MyApplication.getLoaderOptions());
    }

}

到这里，就可以运行程序看看效果啦，过程中有很多辛酸的经历就不回忆了。。。