更改向日葵应用程序ViewModel，仅显示植物列表

Question

我正在尽力将Google的向日葵应用程序用于我的应用程序，如何从对变量" growzoneNumber"的依赖中改变，以便它只返回所有植物？<<<<<<<<

这是Java代码，因为它来自从Google官方Kotlin版本转换为Google的人：

package com.google.samples.apps.sunflower.viewmodels;
import com.google.samples.apps.sunflower.data.Plant;
import com.google.samples.apps.sunflower.data.PlantRepository;
import java.util.List;
import androidx.annotation.NonNull;
import androidx.lifecycle.LiveData;
import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.Transformations;
import androidx.lifecycle.ViewModel;
/**
 * Created by Shawn Wang on 3/26/19.
 */
public class PlantListViewModel extends ViewModel {
    private static final int NO_GROW_ZONE = -1;
    private PlantRepository plantRepository;
    private MutableLiveData<Integer> growZoneNumber;
    public LiveData<List<Plant>> plants;
    PlantListViewModel(@NonNull PlantRepository plantRepository) {
        super();
        this.plantRepository = plantRepository;
        this.growZoneNumber = new MutableLiveData<>(-1);
        this.plants = Transformations.switchMap(growZoneNumber, it -> {
            if (it == NO_GROW_ZONE) {
                return this.plantRepository.getPlants();
            } else {
                return this.plantRepository.getPlantsWIthGrowZoneNumber(it);
            }
        });
    }
    public void setGrowZoneNumber(int num) {
        this.growZoneNumber.setValue(num);
    }
    public void cleanGrowZoneNumber() {
        this.growZoneNumber.setValue(NO_GROW_ZONE);
    }
    public boolean isFiltered() {
        return this.growZoneNumber.getValue() != NO_GROW_ZONE;
    }
}

谢谢。

Answer 1

花了我一段时间来弄清楚，但找到了答案(当然在

内有略有不同的模型

公共类PinViewModel扩展了ViewModel {

private PinRepository pinRepository;
PinViewModel(@NonNull PinRepository pinRepository) {
    this.pinRepository = pinRepository;
}
public LiveData<List<Pin>> getPins() {
    return pinRepository.getPins();
}

}