jetpeck livedata上手實踐——與 ObservableField的差別

問題背景

在日常安卓開發過程中，我們經常會對有些資料進行更新，之前可能會用到ObservableField相關類來進行操作，比如一下demo：

1）建立類SysInfoObs，裡面使用ObservableField<T>。可以定義多個屬性。

public class SysInfoObs {
    public ObservableField<String> info1 = new ObservableField<>(Build.MANUFACTURER);
    public ObservableField<String> timeStr = new ObservableField<>();
    public ObservableField<Long> time = new ObservableField<>();
}

           

2）布局中綁定我們定義的屬性

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">

    <data>
        <variable
            name="info"
            type="com.rustfisher.tutorial2020.databinding.data.SysInfoObs" />
    </data>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:padding="16dp">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@{info.info1}" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@{info.timeStr}" />
    </LinearLayout>
    ...
</layout>
           

3)activity中,建立DataBindingAct2類，持有SysInfoObs的對象。

import android.os.Bundle;
import androidx.databinding.DataBindingUtil;
import androidx.databinding.ObservableArrayList;
import androidx.databinding.ObservableArrayMap;
import com.rustfisher.tutorial2020.AbsActivity;
import com.rustfisher.tutorial2020.R;
import com.rustfisher.tutorial2020.databinding.data.SysInfoObs;
import java.util.Timer;
import java.util.TimerTask;

public class DataBindingAct2 extends AbsActivity {

    private ActDataBinding2Binding binding;
    private SysInfoObs mSysInfo = new SysInfoObs();

    private Timer mTimer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        binding = DataBindingUtil.setContentView(this, R.layout.act_data_binding_2);
        binding.setInfo(mSysInfo);

        mTimer = new Timer();
        mTimer.schedule(new TimerTask() {
            @Override
            public void run() {
                mSysInfo.timeStr.set("Time: " + System.currentTimeMillis());
                mSysInfo.time.set(System.currentTimeMillis());
            }
        }, 0, 500);
    }
    ...
}

           

問題分析

實踐demo