新的分页库的所有示例都使用了Room库,Room为我们创建了一个数据源.在我自己的情况下,我需要创建我的自定义数据源.
@H_301_2@这是我的视图模型类中应该返回实时数据的方法.我的liveata总是返回null.
LiveData<PagedList<ApiResult>> getData(){
LivePagedListProvider<Integer,ApiResult> p = new LivePagedListProvider<Integer,ApiResult>() {
@Override
protected DataSource<Integer,ApiResult> createDataSource() {
return new DataClass();
}
};
listLiveData = p.create(0,new PagedList.Config.Builder()
.setPageSize(5) //number of items loaded at once
.setPrefetchDistance(0)// the distance to the end of already loaded list before new data is loaded
.build());
return listLiveData;
}
@H_301_2@这是Data类
public class DataClass extends TiledDataSource<ApiResult> {
private List<ApiResult> result = new ArrayList<>();
@Override
public int countItems() {
return result.size();
}
@Override
public List<ApiResult> loadRange(int startPosition,int count) {
Call<String> call = NetworkModule.providesWebService().makeRequest();
call.enqueue(new Callback<String>() {
@Override
public void onResponse(@NonNull Call<String> call,@NonNull Response<String> response) {
Log.i(DataClass.this.getClass().getSimpleName() + " - onResponse",String.valueOf(response));
result = parseJson(response.body());
}
@Override
public void onFailure(@NonNull Call<String> call,@NonNull Throwable t) {
Log.i(DataClass.this.getClass().getSimpleName() + " - onFailure",t.getMessage());
}
});
return result;
}
@H_301_2@}
解决方法
我认为这有助于：
1. countItems()应该返回DataSource.COUNT_UNDEFINED
2. loadRange(int startPosition,int count)：您可以直接执行查询.
所以现在你可以删除结果全局变量 @H_301_2@另外,关闭占位符：
https://github.com/brainail/.samples/tree/master/ArchPagingLibraryWithNetwork
1. countItems()应该返回DataSource.COUNT_UNDEFINED
2. loadRange(int startPosition,int count)：您可以直接执行查询.
所以现在你可以删除结果全局变量 @H_301_2@另外,关闭占位符：
listLiveData = p.create(0,new PagedList.Config.Builder()
.setPageSize(5) //number of items loaded at once
.setPrefetchDistance(10) //Must be >0 since placeholders are off
.setEnablePlaceholders(false)
.build());
@H_301_2@以下是Data Class的更新代码：
public class DataClass extends TiledDataSource<ApiResult> {
@Override
public int countItems() {
return DataSource.COUNT_UNDEFINED;
}
@Override
public List<ApiResult> loadRange(int startPosition,int count) {
Call<String> call = NetworkModule.providesWebService().makeRequest();
Response<String> response = call.execute();
return parseJson(response.body());
}
@H_301_2@您可以在此处查看示例项目：https://github.com/brainail/.samples/tree/master/ArchPagingLibraryWithNetwork
