GridView分頁邏輯自定義

在Android中，自定義GridView分頁邏輯可以通過以下步驟實(shí)現(xiàn)：

1. 創(chuàng)建一個(gè)自定義的PaginationAdapter，繼承自BaseAdapter。在這個(gè)類中，你需要實(shí)現(xiàn)分頁邏輯。例如，你可以定義一個(gè)方法isLastPage()來判斷當(dāng)前頁是否是最后一頁，以及一個(gè)方法loadMoreItems()來加載更多數(shù)據(jù)。

public class PaginationAdapter extends BaseAdapter {
    private List<Item> dataList;
    private int currentPage;
    private int pageSize;
    private boolean isLoading;

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

    public void setCurrentPage(int currentPage) {
        this.currentPage = currentPage;
        notifyDataSetChanged();
    }

    public boolean isLastPage() {
        return currentPage * pageSize >= dataList.size();
    }

    public void loadMoreItems() {
        if (isLoading || isLastPage()) {
            return;
        }

        isLoading = true;
        // 模擬加載數(shù)據(jù)的過程
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                int start = currentPage * pageSize;
                int end = Math.min(start + pageSize, dataList.size());
                for (int i = start; i < end; i++) {
                    dataList.add(new Item("Item " + (i + 1)));
                }
                currentPage++;
                isLoading = false;
                notifyDataSetChanged();
            }
        }, 1000);
    }

    // 實(shí)現(xiàn)BaseAdapter的其他方法，如getItem()、getItemId()、getCount()等
}

2. 在你的Activity或Fragment中，創(chuàng)建一個(gè)GridView和一個(gè)PaginationAdapter實(shí)例。然后，為GridView設(shè)置適配器，并監(jiān)聽其滾動(dòng)事件以觸發(fā)分頁加載。

public class MainActivity extends AppCompatActivity {
    private GridView gridView;
    private PaginationAdapter adapter;
    private List<Item> dataList;

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

        gridView = findViewById(R.id.gridview);

        dataList = new ArrayList<>();
        for (int i = 1; i <= 20; i++) {
            dataList.add(new Item("Item " + i));
        }

        adapter = new PaginationAdapter(dataList, 10);
        gridView.setAdapter(adapter);

        gridView.setOnScrollListener(new AbsListView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(AbsListView view, int scrollState) {
            }

            @Override
            public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
                if (!isLoading && !adapter.isLastPage() && firstVisibleItem + visibleItemCount >= totalItemCount) {
                    adapter.loadMoreItems();
                }
            }
        });
    }
}

這樣，當(dāng)用戶滾動(dòng)到GridView底部時(shí)，將自動(dòng)加載更多數(shù)據(jù)并顯示在GridView中。你可以根據(jù)實(shí)際需求調(diào)整分頁邏輯和樣式。