Android 9.0版本及以上开发时遇到的一些版本问题

1.使用通知以及PendingIntent

if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
                    Context context=getApplicationContext();
                    Intent intent = new Intent(context, notification.class);
                    PendingIntent pendingIntent = PendingIntent.getActivity(
                            context,1,intent,PendingIntent.FLAG_UPDATE_CURRENT
                    );

                    String channelId = "ChannelId";
                    NotificationManager manager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
                    Notification notification = new Notification.Builder(context)
                            .setChannelId(channelId)
                            .setContentTitle("This is content title")
                            .setContentText("This is content text")
                            .setWhen(System.currentTimeMillis())
                            .setSmallIcon(R.mipmap.ic_launcher)
                            .setLargeIcon(BitmapFactory.decodeResource(getResources(),R.mipmap.ic_launcher))
                            .setContentIntent(pendingIntent)
                            .setAutoCancel(true)
                            .setVibrate(new long[]{0,1000,1000,1000})
                            .build();
                    NotificationChannel channel = new NotificationChannel(channelId,"渠道名称",NotificationManager.IMPORTANCE_DEFAULT);
                    manager.createNotificationChannel(channel);
                    manager.notify(1,notification);
                }

 

2.使用前台服务

要加上权限

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

同时通知部分的代码也要修改

//android 8.0以后新增
        String CHANNEL_ONE_ID="com.example.servicetest";
        String CHANNEL_ONE_NAME = "Channel One";
        NotificationChannel notificationChannel = null;
        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
            notificationChannel = new NotificationChannel(CHANNEL_ONE_ID,CHANNEL_ONE_NAME, NotificationManager.IMPORTANCE_HIGH);
            notificationChannel.enableLights(true);
            notificationChannel.setLightColor(Color.RED);
            notificationChannel.setShowBadge(true);
            notificationChannel.setLockscreenVisibility(Notification.VISIBILITY_PUBLIC);
            NotificationManager manager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
            manager.createNotificationChannel(notificationChannel);

            //创建前台服务
            Intent intent = new Intent(this,MainActivity.class);
            PendingIntent pi = PendingIntent.getActivity(this,0,intent,0);
            Notification notification = new Notification.Builder(this)
                    .setChannelId(CHANNEL_ONE_ID)//新增
                    .setContentTitle("This is content title")
                    .setContentText("This is content title")
                    .setWhen(System.currentTimeMillis())
                    .setSmallIcon(R.mipmap.ic_launcher)
                    .setContentIntent(pi)
                    .build();
            notification.flags |= Notification.FLAG_NO_CLEAR;//新增
            startForeground(1,notification);
        }

 3.okhttp

注册文件里新加

android:usesCleartextTraffic="true"
android:networkSecurityConfig="@xml/network_security_config"

在res下新建xml目录，新建文件 network_security_config.xml

<?xml version="1.0" encoding="utf-8"?>
<network-security-config >

    <base-config cleartextTrafficPermitted="true" />
</network-security-config>

同时gradle文件里两处新加

android 包里 

compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

dependencies 包里

    implementation 'com.squareup.okhttp3:okhttp:3.14.2'

 

4.新建项目时build问题

切换镜像源，使用vpn，在gradle所有

repositories

里添加

maven{ url 'http://maven.aliyun.com/nexus/content/repositories/central/'}

 

5.support.v4,v7,v13里的控件（toolbar，reycleview），现在都可以在androidx里面找了，直接导入对应的androidx.包即可

 

6.使用NavigationView

在build里添加

implementation 'de.hdodenhof:circleimageview:2.1.0'
implementation 'com.android.support:design:29.1.1'

使用的时候是

<com.google.android.material.navigation.NavigationView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/nav_view"
        app:menu="@menu/nav_menu"
        android:layout_gravity="start"
        app:headerLayout="@layout/nav_header"/>

 

7.  使用litepal

首先在gradle里加上

implementation 'org.litepal.android:java:3.0.0'

然后在main下新建asserts目录，目录下新建 litepal.xml

<?xml version="1.0" encoding="utf-8" ?>
<litepal>
    <dbname value="BookStore" ></dbname>
    <version value="2" ></version>

    <list>
        <mapping class="com.example.litepal.Book"></mapping>
        <mapping class="com.example.litepal.Category"></mapping>
    </list>
</litepal>

注册文件里再加

android:name="org.litepal.LitePalApplication"

 litepal 2.0以后有了新的api

　　首先DataSupport -> LitepalSupport

 

8.使用下拉刷新

androidx.swiperefreshlayout.widget.SwipeRefreshLayout 

要在build里导入一个design包

implementation 'com.android.support:design:29.1.1'