在该列上触摸Gridview的上移和下移列

Question

我有一个3x3网格视图.想象一下如下.

1 2 3
4 5 6
7 8 9

现在我想要达到什么目标

我希望网格视图列在触摸时向上和向下移动.

考虑一下网格视图的第一列.那是

1
4
7

现在,如果我触摸此列的任何位置,可以在1或4或7上触摸,然后向上或向下滑动任何一个方向.然后我想将列移动1或2个位置.

让我明白一下

如果我通过触摸7向上滑动它应该是这样的结果

1
4 2 3
7 5 6 
  8 9

或者,如果我触摸第二列并将其向下移动,那么它将如下所示

1   3
4 2 6
7 5 9
  8

如果我移动2个网格单元格的列,那么它看起来就像

1   3
4   6
7 2 9
  5
  8

对于每一列,我应该能够将列移动一个或两个单元格,具体取决于我滚动列的数量.

还有一件事如果我将列滚动得很小并且如果它不是完全适合任何网格单元到所需位置那么它应该自动适合接近适合位置的网格单元.

我在这里搜索了太多关于堆栈溢出的问题并查询谷歌批次.但我没有得到我想要的东西.

如果我没有解释好,请告诉我.我会尝试解释更多.任何想法,任何提示或任何技巧都是值得的.

编辑

如果我移动列超过3个网格然后释放触摸,则列将仅移动到两个元素.像这样

1   3
4   6
7 2 9
  5
  8

任何开始的想法都会很明显

谢谢

Answer 1

要做你要求的事情就需要你负责GridView画布,从被触摸的栏目中划出部分并为拖动,拖曳等做自己的绘画.一旦动作完成,你需要调整通过列中的视图GridView来保持记账直线.我会看一下讨论视图移动的在线文档."拖拽和缩放"将是一个很好的起点.

这种方法会有一些"陷阱".如果你只是想把它作为一种技术来学习,那么我会说你的方法没问题.如果你想完成效果并使用GridView设计的底层实现(滚动,边缘效果,flings等),我建议另一种方法.

通过并排排列三个1x3网格视图,GridView您可以建立一个相似的3x3而不是单个3x3 GridView.(实际上网格视图将是1x11以适应垂直幻灯片的最大范围.)如果编码为支持多个网格视图,则每个网格视图可由单个适配器支持.由于每列都是自己的网格视图,因此每列可以独立于其他列滑动.

这种方法的优点是可以在不扭曲底层GridView类的情况下获得所需的效果.这种方法可以使用现有的使用按钮的方法.

我希望这对你有所帮助.

我很想知道如何实施我的建议.下面是一个示例应用程序,其中包含上述三种GridView实现方式以及相同的视频.

MainActivity.java

public class MainActivity extends AppCompatActivity
        implements GridView.OnScrollListener {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        final GridViewAdapter adapter = new GridViewAdapter();

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setupGridView(R.id.gridview0, adapter);
        setupGridView(R.id.gridview1, adapter);
        setupGridView(R.id.gridview2, adapter);
    }

    private void setupGridView(int id, GridViewAdapter adapter) {
        final GridView gridview = (GridView) findViewById(id);

        gridview.setAdapter(adapter);
        // Temporary scroll listener until initial scroll to position is done.
        // This hides the initial movement of the grid cells.
        gridview.setOnScrollListener(new AbsListView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(AbsListView view, int scrollState) {
                if (scrollState == AbsListView.OnScrollListener.SCROLL_STATE_IDLE) {
                    gridview.setOnScrollListener(MainActivity.this);
                }
            }

            @Override
            public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
                // Do nothing
            }
        });
        gridview.smoothScrollToPositionFromTop(2, 0);
    }

    @Override
    public void onScrollStateChanged(AbsListView view, int scrollState) {
        if (scrollState == AbsListView.OnScrollListener.SCROLL_STATE_IDLE) {
            final int top = view.getChildAt(0).getTop();
            final int itemHeight = ((GridViewAdapter) (view.getAdapter())).getItemHeight();

            // top <= 0
            if (top > -(itemHeight / 2)) {
                // Less than 1/2 cell height out of place - shift down.
                view.scrollListBy(top);
            } else {
                // Shift up
                view.scrollListBy(top + itemHeight);
            }
        }
    }

    @Override
    public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
        // Do nothing
    }

    @SuppressWarnings("unused")
    private static final String TAG = "MainActivity";
}

GridViewAdapter.java

class GridViewAdapter extends BaseAdapter {

    GridViewAdapter() {
    }

    @Override
    public int getCount() {
        return mStrings.length / GRID_COLUMN_COUNT;
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    // create a new TextView for each item referenced by the Adapter
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        TextView textView;
        final int column = Integer.parseInt((String) parent.getTag());

        if (convertView == null) {
            // if it's not recycled, initialize some attributes
            textView = new TextView(parent.getContext());
            GridView.LayoutParams params =
                    new GridView.LayoutParams(GRID_ITEM_WIDTH, GRID_ITEM_HEIGHT);
            textView.setLayoutParams(params);
            textView.setTextSize(TypedValue.COMPLEX_UNIT_SP, 20);
            textView.setGravity(Gravity.CENTER);
        } else {
            // Recycle the view but keep old attributes since they don't change.
            textView = (TextView) convertView;
        }
        textView.setText(mStrings[position * GRID_COLUMN_COUNT + column]);
        return textView;
    }

    int getItemHeight() {
        return GRID_ITEM_HEIGHT;
    }

    private final static String[] mStrings = {
            "", "", "",
            "", "", "",
            "", "", "",
            "", "", "",
            "1", "2", "3",
            "4", "5", "6",
            "7", "8", "9",
            "", "", "",
            "", "", "",
            "", "", "",
            "", "", ""
    };

    private static final int GRID_ITEM_HEIGHT = 150; // in pixels
    private static final int GRID_ITEM_WIDTH = 150; // in pixels
    private static final int GRID_COLUMN_COUNT = 3;

}

activity_main.java

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/linearLayout"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:orientation="horizontal">

    <!-- Sorry for the dimensions in pixels. It just makes everything easier.
    Non-pixel dimensions (dp) should be used here and accommodations made in the code. -->

    <GridView xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/gridview0"
        android:layout_width="150px"
        android:layout_height="1050px"
        android:columnWidth="150px"
        android:horizontalSpacing="0dp"
        android:numColumns="1"
        android:scrollbars="none"
        android:tag="0"
        android:verticalSpacing="0dp" />

    <GridView xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/gridview1"
        android:layout_width="150px"
        android:layout_height="1050px"
        android:columnWidth="150px"
        android:horizontalSpacing="0dp"
        android:numColumns="1"
        android:scrollbars="none"
        android:tag="1"
        android:verticalSpacing="0dp" />

    <GridView xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/gridview2"
        android:layout_width="150px"
        android:layout_height="1050px"
        android:columnWidth="150px"
        android:horizontalSpacing="0dp"
        android:numColumns="1"
        android:scrollbars="none"
        android:tag="2"
        android:verticalSpacing="0dp" />
</LinearLayout>