Question

我创建了一个gridview，我需要在用户向下滚动10个项目后加载更多，例如，一个按钮会出现更多，我需要在网格内的项目列表中追加10个项目，这是我的代码：

MainActivity.java

public class MainActivity extends ActionBarActivity {

private List<GridItem> correspondenceList;
GridView gridView;

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

    gridView = (GridView) findViewById(R.id.grid_view);
    correspondenceList = new ArrayList<GridItem>();
    correspondenceList.add(new GridItem("1", "subj1"));
    correspondenceList.add(new GridItem("2", "subj2"));
    correspondenceList.add(new GridItem("3", "subj3"));
    correspondenceList.add(new GridItem("4", "subj4"));
    correspondenceList.add(new GridItem("5", "subj5"));
    correspondenceList.add(new GridItem("6", "subj6"));
    correspondenceList.add(new GridItem("7", "subj7"));
    correspondenceList.add(new GridItem("8", "subj8"));
    correspondenceList.add(new GridItem("9", "subj9"));
    correspondenceList.add(new GridItem("10", "subj10"));
    correspondenceList.add(new GridItem("11", "subj11"));


    MyArrayAdapteradapter = new MyArrayAdapter(this, R.layout.grid_item, correspondenceList);
    gridView.setAdapter(adapter);

}

MyArrayAdapter.java

public class MyArrayAdapter extends BaseAdapter{
private Context context;
private int resourceId;
private List<Correspondance> fields;

public MyArrayAdapter(Context context, int resource, List<GridItem> objects) {
    this.context = context;
    this.resourceId = resource;
    this.fields = objects;
    notifyDataSetChanged();
}

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    if (convertView == null) {
        LayoutInflater inflater = ((Activity) this.context)
                .getLayoutInflater();
        convertView = inflater.inflate(this.resourceId, parent, false);

    }
    GridItem corres = fields.get(position);

    TextView gridSubjectTextView = (TextView) convertView
            .findViewById(R.id.grid_subj);

    gridSubjectTextView.setText(Html.fromHtml("<big><b>Subject</b><br></big><i>" + corres.subject + "</i><br>"));

    return convertView;
}

activity_main.xml中

<GridView
    android:id="@+id/grid_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:columnWidth="100dp"
    android:numColumns="2"
    android:gravity="center"
    android:horizontalSpacing="30dp"
    android:verticalSpacing="30dp"
    android:paddingTop="30dp"
    android:paddingLeft="20dp"
    android:paddingRight="20dp"
    android:clipToPadding="false"
    android:scrollbars="horizontal"
    android:stretchMode="columnWidth" />

Answer 1

你可以这样做。

public class MainActivity extends ActionBarActivity implements  OnScrollListener {

private List<GridItem> correspondenceList;
GridView gridView;
    private int currentFirstVisibleItem;
    private int currentVisibleItemCount;
    private int currentScrollState;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    gridView = (GridView) findViewById(R.id.grid_view);
    correspondenceList = new ArrayList<GridItem>();
    correspondenceList.add(new GridItem("1", "subj1"));
    correspondenceList.add(new GridItem("2", "subj2"));
    correspondenceList.add(new GridItem("3", "subj3"));
    correspondenceList.add(new GridItem("4", "subj4"));
    correspondenceList.add(new GridItem("5", "subj5"));
    correspondenceList.add(new GridItem("6", "subj6"));
    correspondenceList.add(new GridItem("7", "subj7"));
    correspondenceList.add(new GridItem("8", "subj8"));
    correspondenceList.add(new GridItem("9", "subj9"));
    correspondenceList.add(new GridItem("10", "subj10"));
    correspondenceList.add(new GridItem("11", "subj11"));


    MyArrayAdapteradapter = new MyArrayAdapter(this, R.layout.grid_item, correspondenceList);
    gridView.setAdapter(adapter);

gridView.setOnScrollListener(this);

}


    @Override
    public void onScroll(AbsListView view, int firstVisibleItem,
            int visibleItemCount, int totalItemCount) {

        this.currentFirstVisibleItem = firstVisibleItem;
        this.currentVisibleItemCount = visibleItemCount;
    }

    @Override
    public void onScrollStateChanged(AbsListView view, int scrollState) {

        this.currentScrollState = scrollState;
        this.isScrollCompleted();


    }

    private void isScrollCompleted() {
        if (this.currentVisibleItemCount > 0 && this.currentScrollState == SCROLL_STATE_IDLE) {
            /*** In this way I detect if there's been a scroll which has completed ***/
            /*** do the work for load more date! ***/

            }
        }
    }

在适配器中有一个覆盖方法

@Override
    public int getCount() {
        // TODO Auto-generated method stub
        return fields!= null ? fields.size() : 0;
    }

所以你需要在滚动时更改getCount()的值，以获得每10条记录的完整记录。

Answer 2

这是我如何解决我的问题：首先设置private int startIndex = 0

和private List<Items> currentItemsList; 然后在onCreate中输入此代码：

    getItems(startIndex);
    GridView gridViewItems = (GridView) findViewById(R.id.grid_view);
            gridViewItems.setOnScrollListener(new AbsListView.OnScrollListener() {
                @Override
                public void onScroll(AbsListView view, int firstVisibleItem,
                                     int visibleItemCount, int totalItemCount) {
                    //leave this empty
                }

                @Override
                public void onScrollStateChanged(AbsListView listView, int scrollState) {

                    if (scrollState == SCROLL_STATE_IDLE) {
                        if (listView.getLastVisiblePosition() >= listView.getCount() - 1 - threshold) {
                            //load more list items:
                                startIndex = startIndex + 
                                getItems(startIndex);
                    }
                }
            });

然后在getItems（）方法中：

private void getItems(int index) {
                if (PerCurrentItemsData.getTotalItemsNumber() <= index &&
                        PerCurrentIemsData.getTotalItemsNumber() != 0) {
                   //do nothing
    //NOTE: where PerCurrentItemsData.getTotalItemsNumber() is a static method  in 
// PerCurrentItemsData class filled on app creations that return the total number of items
                } else { 
PerCurrentItemsData.getCurrentItems().addAll(//retreive list of items to show next);
                            currentItemsList = PerCurrentItemsData.getCurrentItems();
                        }
                        if (result.getInbox().getCorrespondences().size() != 0) {
                ItemsListArrayAdapter adapter =
                                    new ItemsListArrayAdapter(context, R.layout.grid_item, currentItemsList);
                            gridView.setAdapter(adapter);
                            gridView.setSelection(index);
                        } else if (currentItemsList.size() == 0) {
                            ItemsListArrayAdapter adapter =
                                    new ItemsListArrayAdapter(context, R.layout.grid_item, new ArrayList<Items>());
                            gridView.setAdapter(adapter);
                        } else if (currentItemsList.size() == 0) {

                        }
                }
            }

我希望这会有所帮助，它对我有用，如有任何进一步的信息，请问我

GridView with Load更多在android中

2 个答案: