实现Android分页搜索的一种常用方法是使用RecyclerView和Paging Library。以下是一个示例,包含一个包含搜索关键字的EditText,以及一个初始化PagedList的方法:
// 获取搜索关键字EditText
EditText searchEditText = findViewById(R.id.search_edit_text);
// 实例化ViewModel和DataSourceFactory
MyViewModel viewModel = new ViewModelProvider(this).get(MyViewModel.class);
MyDataSourceFactory dataSourceFactory = new MyDataSourceFactory(viewModel, searchEditText.getText().toString());
// 配置PagedList的配置信息
PagedList.Config config = new PagedList.Config.Builder()
.setPageSize(20)
.setPrefetchDistance(40)
.setEnablePlaceholders(true)
.build();
// 初始化PagedList
LiveData> pagedListLiveData = new LivePagedListBuilder<>(dataSourceFactory, config).build();
// 将PagedList设置给RecyclerView的Adapter
RecyclerView recyclerView = findViewById(R.id.recycler_view);
MyAdapter myAdapter = new MyAdapter();
pagedListLiveData.observe(this, myAdapter::submitList);
recyclerView.setAdapter(myAdapter);
在DataSourceFactory中,我们可以使用SearchDataSource来实现搜索并返回分页数据。以下是一个示例:
public class MyDataSourceFactory extends DataSource.Factory {
private final MyViewModel viewModel;
private String searchText;
public MyDataSourceFactory(MyViewModel viewModel, String searchText) {
this.viewModel = viewModel;
this.searchText = searchText;
}
@Override
public DataSource create() {
return new MyPageDataSource(viewModel, searchText);
}
public void setSearchText(String searchText) {
this.searchText = searchText;
}
}
在SearchDataSource中,我们可以使用Room数据库实现搜索并返回分页数据。以下是一个示例:
public class MyPageDataSource extends PageKeyedDataSource {
private final String searchText;
public MyPageDataSource(MyViewModel viewModel, String searchText) {
this.searchText = searchText;
}
@Override
public void loadInitial(@NonNull LoadInitialParams params, @NonNull LoadInitialCallback callback) {
// 从Room数据库中获取第一页数据并回调
}
@Override
public void loadBefore(@NonNull LoadParams params, @NonNull LoadCallback callback) {
// 暂未实现
}
@Override
public void loadAfter(@NonNull LoadParams params, @NonNull LoadCallback callback) {
// 从Room数据库中获取下一页数据并回调
}
}