添加鼠标侦听器以放置目标

Question

DefaultTableModel modeltable = new DefaultTableModel(8,8);

table = new JTable(modeltable);
table.setBorder(BorderFactory.createLineBorder (Color.blue, 2));

int height = table.getRowHeight();
table.setRowHeight(height=50);

table.setColumnSelectionAllowed(true);
table.setDragEnabled(true);

le1.setFillsViewportHeight(true);

panel.add(table);
panel.setSize(400,400);

    DnDListener dndListener = new DnDListener();
    DragSource dragSource = new DragSource();
    DropTarget dropTarget1 = new DropTarget(table, dndListener);

   DragGestureRecognizer dragRecognizer2 = dragSource.
            createDefaultDragGestureRecognizer(option1, 
          DnDConstants.ACTION_COPY, dndListener);
   DragGestureRecognizer dragRecognizer3 = dragSource.
            createDefaultDragGestureRecognizer(option2, 
            DnDConstants.ACTION_COPY, dndListener);


}
}

我有一个问题,将鼠标监听器添加到"table"这是drop target,接受drop组件从鼠标中掉落的地方.在此代码中,当组件进入放置目标时,它总是进入默认位置.我无法自定义放置目标上的位置.请有人帮我这个.提前致谢

Answer 1

那些听众太低级了.实现dnd的适当方法是实现自定义TransferHandler并将该自定义处理程序设置为您的表.

 public class MyTransferHandler extends TransferHandler {

    public boolean canImport(TransferHandler.TransferSupport info) {
        // we only import Strings
        if (!info.isDataFlavorSupported(DataFlavor.stringFlavor)) {
            return false;
        }

        JTable.DropLocation dl = (JTable.DropLocation)info.getDropLocation();
        // ... your code to decide whether the data can be dropped based on location 
    }

    public boolean importData(TransferHandler.TransferSupport info) {
        if (!info.isDrop()) {
            return false;
        }

        // Check for String flavor
        if (!info.isDataFlavorSupported(DataFlavor.stringFlavor)) {
            displayDropLocation("Table doesn't accept a drop of this type.");
            return false;
        }

        JTable.DropLocation dl = (JTable.DropLocation)info.getDropLocation();
        // ... your code to handle the drop
   }

}

// usage
myTable.setTransferHandler(new MyTransferHandler());

有关详细信息,请参阅Swing标记描述中链接的在线教程中的示例,即拖放一章上面的代码片段是从BasicDnD示例中获取的.