GridView分页显示与数据分页逻辑实现

在Android开发中，GridView分页显示和数据分页逻辑可以通过以下步骤实现：

1. 数据分页

首先，你需要实现数据的分页逻辑。假设你有一个数据源列表，你可以将其分成多个页面。

public class PaginationHelper {
    private List<Item> dataList;
    private int pageSize;
    private int currentPage;

    public PaginationHelper(List<Item> dataList, int pageSize) {
        this.dataList = dataList;
        this.pageSize = pageSize;
        this.currentPage = 1;
    }

    public List<Item> getPaginatedData() {
        int fromIndex = (currentPage - 1) * pageSize;
        int toIndex = Math.min(fromIndex + pageSize, dataList.size());
        return dataList.subList(fromIndex, toIndex);
    }

    public void nextPage() {
        currentPage++;
    }

    public boolean hasNextPage() {
        return (currentPage - 1) * pageSize < dataList.size();
    }
}

2. GridView分页显示

接下来，你需要在GridView中实现分页显示。你可以使用一个适配器来管理GridView的项，并在适配器中处理分页逻辑。

public class PaginationGridViewAdapter extends BaseAdapter {
    private List<Item> dataList;
    private Context context;
    private PaginationHelper paginationHelper;

    public PaginationGridViewAdapter(Context context, List<Item> dataList, int pageSize) {
        this.context = context;
        this.dataList = dataList;
        this.paginationHelper = new PaginationHelper(dataList, pageSize);
    }

    @Override
    public int getCount() {
        return paginationHelper.getPaginatedData().size();
    }

    @Override
    public Object getItem(int position) {
        return paginationHelper.getPaginatedData().get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if (convertView == null) {
            convertView = LayoutInflater.from(context).inflate(R.layout.grid_item, parent, false);
        }

        Item item = paginationHelper.getPaginatedData().get(position);
        // 设置项的视图内容
        TextView textView = convertView.findViewById(R.id.textView);
        textView.setText(item.getText());

        return convertView;
    }

    public void nextPage() {
        notifyDataSetChanged();
        paginationHelper.nextPage();
    }

    public boolean hasNextPage() {
        return paginationHelper.hasNextPage();
    }
}

3. 在Activity中实现分页逻辑

最后，在Activity中实现分页逻辑，例如使用按钮来切换页面。

public class MainActivity extends AppCompatActivity {
    private GridView gridView;
    private PaginationGridViewAdapter adapter;
    private PaginationHelper paginationHelper;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        gridView = findViewById(R.id.gridView);
        List<Item> dataList = getDataList(); // 获取数据列表
        int pageSize = 10; // 每页显示10个项
        adapter = new PaginationGridViewAdapter(this, dataList, pageSize);
        gridView.setAdapter(adapter);

        Button nextPageButton = findViewById(R.id.nextPageButton);
        nextPageButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                adapter.nextPage();
            }
        });
    }

    private List<Item> getDataList() {
        // 模拟获取数据列表
        List<Item> dataList = new ArrayList<>();
        for (int i = 1; i <= 100; i++) {
            dataList.add(new Item("Item " + i));
        }
        return dataList;
    }
}

4. 布局文件

确保你的布局文件中包含GridView和按钮。

<!-- activity_main.xml -->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/nextPageButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Next Page"/>

    <GridView
        android:id="@+id/gridView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:numColumns="auto_fit"
        android:columnWidth="100dp"
        android:horizontalSpacing="10dp"
        android:verticalSpacing="10dp"
        android:stretchMode="columnWidth"/>
</LinearLayout>

通过以上步骤，你就可以实现GridView的分页显示和数据分页逻辑了。