Android常用零散知识点

好久没有写过安卓了，动手又写了安卓代码，有些生疏，公司的电脑不让用USB接入手机，无奈只能另想办法调试。不过好在做出了app的雏形，可以实现监控系统的通知，对关键信息进行过滤，然后再次提醒。

记一下值得留意的知识点

Andoird输出日志到本地存储

1. 使用权限

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

2. 添加日志库

    implementation 'de.mindpipe.android:android-logging-log4j:1.0.3'
    implementation 'log4j:log4j:1.2.17'

3. 配置日志输出到本地存储

public class ALogger {
    public static org.apache.log4j.Logger getLogger(Class clazz) {
        final LogConfigurator logConfigurator = new LogConfigurator();
//        logConfigurator.setFileName(Environment.getExternalStorageDirectory().toString() + File.separator + "log/monitor_dingding.log");
        logConfigurator.setFileName(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS) + File.separator + "log/monitor_dingding.txt");
        String fileName = logConfigurator.getFileName();
        File file = new File(fileName);
        if (!file.exists()){
            try {
                file.createNewFile();
            } catch (IOException e) {
//                e.printStackTrace();
                Log.w(MainActivity.TAG,"创建文件失败" + e.getMessage());
            }
        }
        Log.w(MainActivity.TAG,"日志文件名：" + fileName);
        logConfigurator.setRootLevel(Level.ALL);
        logConfigurator.setLevel("org.apache", Level.ALL);
        logConfigurator.setUseFileAppender(true);
        logConfigurator.setFilePattern("%d %-5p [%c{2}]-[%L] %m%n");
        logConfigurator.setMaxFileSize(1024 * 1024 * 5);
        logConfigurator.setImmediateFlush(true);
        logConfigurator.configure();
        Logger log = Logger.getLogger(clazz);
        return log;
    }
}

4. 写日志

 ALogger.getLogger(getClass()).log(Level.INFO,"发送了通知：" + builder.toString());

构建本地通知

1. 创建通知的channel

    
     private void createNotificationChannel() {
        // Create the NotificationChannel, but only on API 26+ because
        // the NotificationChannel class is new and not in the support library
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            CharSequence name = getString(R.string.channel_name);
            String description = getString(R.string.channel_description);
            int importance = NotificationManager.IMPORTANCE_DEFAULT;
            NotificationChannel channel = new NotificationChannel(CHANNEL_ID, name, importance);
            channel.setDescription(description);
            // Register the channel with the system; you can't change the importance
            // or other notification behaviors after this
            NotificationManager notificationManager = getSystemService(NotificationManager.class);
            notificationManager.createNotificationChannel(channel);
        }
    }

2. 使用Channel发送通知

    boolean channelCreated = false;

    @OnClick(R.id.sendNotify)
    public void sendNotify(){
        if (!channelCreated){
            createNotificationChannel();
            channelCreated = true;
        }
        NotificationCompat.Builder builder = new NotificationCompat.Builder(this, CHANNEL_ID)
                .setSmallIcon(R.mipmap.ic_launcher)
                .setContentTitle("title")
                .setContentText("text")
                .setPriority(NotificationCompat.PRIORITY_DEFAULT);

        NotificationManagerCompat notificationManager = NotificationManagerCompat.from(this);

// notificationId is a unique int for each notification that you must define
        notificationManager.notify((int) System.currentTimeMillis() / 1000, builder.build());
        ALogger.getLogger(getClass()).log(Level.INFO,"发送了通知：" + builder.toString());
    }

构建显示的对话框

1. 添加依赖

implementation 'com.afollestad.material-dialogs:core:0.9.6.0'

2. 使用，注意传入的Context是当前对话框所在的Context

MaterialDialog dialog = new MaterialDialog.Builder(ListActivity.this)
                .title("提示")//标题
                .content("确认要删除吗？")//内容
//                        .icon(getResources().getDrawable(R.mipmap.ic_logo,null))//图标
                .positiveText("确定") //肯定按键
//                        .neutralText("稍后询问")  //中性按键
                .negativeText("取消") //否定按键
                .cancelable(true)
                .onPositive(new MaterialDialog.SingleButtonCallback() { //监听肯定按键
                    @Override
                    public void onClick(@NonNull MaterialDialog dialog, @NonNull DialogAction which) {
                        adapter.getData().remove(position);
                        adapter.refreshNotifyItemChanged(position);

                        SharedPreferences sp = getSharedPreferences(Constant.SP_NAME, 0);
                        SharedPreferences.Editor spEditor = sp.edit();
                        spEditor.putString(Constant.SP_KEY_FILTER,JSON.toJSONString(adapter.getData()));
                        spEditor.commit();

                        Toast.makeText(getApplicationContext(), "成功删除",
                                Toast.LENGTH_SHORT).show();
                    }
                })

                .onNegative(new MaterialDialog.SingleButtonCallback() { //监听否定按键
                    @Override
                    public void onClick(@NonNull MaterialDialog dialog, @NonNull DialogAction which) {

                    }
                })
                .build();
        dialog.show();

最后

写安卓还是有点手生啊，做出来的app给别人不是很好用。