Java 如何在 JTable 中拖放一行？
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原文地址: http://stackoverflow.com/questions/638807/
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How do I drag and drop a row in a JTable?
提问by ShawnD
How do you setup a JTable to be able to drag a row to a different index in the table. For example if I have 5 rows and I want to drag the 4th row to the 2nd position?
您如何设置 JTable 以便能够将行拖动到表中的不同索引。例如，如果我有 5 行并且我想将第 4 行拖到第 2 位？
采纳答案by Bogdan
Check out the drag and dropsection of the Java Tutorial. There are some examples on how to implement this for JTable.
查看Java 教程的拖放部分。有一些关于如何为JTable.
回答by Tobias
perhaps sth. like this:
也许…… 像这样：
table.addMouseMotionListener(new MouseMotionListener() {
public void mouseDragged(MouseEvent e) {
e.consume();
JComponent c = (JComponent) e.getSource();
TransferHandler handler = c.getTransferHandler();
handler.exportAsDrag(c, e, TransferHandler.MOVE);
}
public void mouseMoved(MouseEvent e) {
}
});
回答by Aaron Davidson
The following allows JTable re-ordering of a single dragged row:
以下允许 JTable 对单个拖动行重新排序：
table.setDragEnabled(true);
table.setDropMode(DropMode.INSERT_ROWS);
table.setTransferHandler(new TableRowTransferHandler(table));
Your TableModel should implement the following to allow for re-ordering:
您的 TableModel 应实现以下内容以允许重新排序：
public interface Reorderable {
public void reorder(int fromIndex, int toIndex);
}
This TransferHandler class handles the drag & drop, and calls reorder() on your TableModel when the gesture is completed.
这个 TransferHandler 类处理拖放，并在手势完成时调用 TableModel 上的 reorder()。
/**
* Handles drag & drop row reordering
*/
public class TableRowTransferHandler extends TransferHandler {
private final DataFlavor localObjectFlavor = new ActivationDataFlavor(Integer.class, "application/x-java-Integer;class=java.lang.Integer", "Integer Row Index");
private JTable table = null;
public TableRowTransferHandler(JTable table) {
this.table = table;
}
@Override
protected Transferable createTransferable(JComponent c) {
assert (c == table);
return new DataHandler(new Integer(table.getSelectedRow()), localObjectFlavor.getMimeType());
}
@Override
public boolean canImport(TransferHandler.TransferSupport info) {
boolean b = info.getComponent() == table && info.isDrop() && info.isDataFlavorSupported(localObjectFlavor);
table.setCursor(b ? DragSource.DefaultMoveDrop : DragSource.DefaultMoveNoDrop);
return b;
}
@Override
public int getSourceActions(JComponent c) {
return TransferHandler.COPY_OR_MOVE;
}
@Override
public boolean importData(TransferHandler.TransferSupport info) {
JTable target = (JTable) info.getComponent();
JTable.DropLocation dl = (JTable.DropLocation) info.getDropLocation();
int index = dl.getRow();
int max = table.getModel().getRowCount();
if (index < 0 || index > max)
index = max;
target.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
try {
Integer rowFrom = (Integer) info.getTransferable().getTransferData(localObjectFlavor);
if (rowFrom != -1 && rowFrom != index) {
((Reorderable)table.getModel()).reorder(rowFrom, index);
if (index > rowFrom)
index--;
target.getSelectionModel().addSelectionInterval(index, index);
return true;
}
} catch (Exception e) {
e.printStackTrace();
}
return false;
}
@Override
protected void exportDone(JComponent c, Transferable t, int act) {
if ((act == TransferHandler.MOVE) || (act == TransferHandler.NONE)) {
table.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
}
}
}
回答by Soley
Just for the records and multiple row re-ordering:
仅用于记录和多行重新排序：
use somewhere....
在某处使用....
JTable table = t_objects;
table.setDragEnabled(true);
table.setDropMode(DropMode.INSERT_ROWS);
table.setTransferHandler(new TableRowTransferHandler(table));
This is the main class in the above answer, I modified that to match the needs for multiple row DnD. All I did was to use the first selected row, then calculate the rows above the drop place. Removed seleced items and keep them in a list of objects (row array object). then insert them back to calculated row. and finally select the removed/dragged rows to complete the process.
这是上述答案中的主要类，我对其进行了修改以匹配多行 DnD 的需求。我所做的就是使用第一个选定的行，然后计算放置位置上方的行。删除了选择的项目并将它们保存在对象列表中（行数组对象）。然后将它们插入回计算行。最后选择删除/拖动的行以完成该过程。
public class TableRowTransferHandler extends TransferHandler {
private final DataFlavor localObjectFlavor = new DataFlavor(Integer.class, "Integer Row Index");
private JTable table = null;
public TableRowTransferHandler(JTable table) {
this.table = table;
}
@Override
protected Transferable createTransferable(JComponent c) {
assert (c == table);
return new DataHandler(new Integer(table.getSelectedRow()), localObjectFlavor.getMimeType());
}
@Override
public boolean canImport(TransferHandler.TransferSupport info) {
boolean b = info.getComponent() == table && info.isDrop() && info.isDataFlavorSupported(localObjectFlavor);
table.setCursor(b ? DragSource.DefaultMoveDrop : DragSource.DefaultMoveNoDrop);
return b;
}
@Override
public int getSourceActions(JComponent c) {
return TransferHandler.COPY_OR_MOVE;
}
@Override
public boolean importData(TransferHandler.TransferSupport info) {
JTable target = (JTable) info.getComponent();
JTable.DropLocation dl = (JTable.DropLocation) info.getDropLocation();
int index = dl.getRow();
int max = table.getModel().getRowCount();
if (index < 0 || index > max) {
index = max;
}
target.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
try {
Integer rowFrom = (Integer) info.getTransferable().getTransferData(localObjectFlavor);
if (rowFrom != -1 && rowFrom != index) {
int[] rows = table.getSelectedRows();
int dist = 0;
for (int row : rows) {
if (index > row) {
dist++;
}
}
index -= dist;
//**TableUtil** is a simple class that just copy, remove and select rows.
ArrayList<Object> list = TableUtil.getSelectedList(table);
TableUtil.removeSelected(table);
ArrayList<Integer> sels = new ArrayList<Integer>();
for (Object obj : list) {
sels.add(index);
TableUtil.addRowAt(table, obj, index++);
}
TableUtil.selectMultipleRow(table, sels);
return true;
}
} catch (Exception e) {
e.printStackTrace();
}
return false;
}
@Override
protected void exportDone(JComponent c, Transferable t, int act) {
if (act == TransferHandler.MOVE) {
table.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
}
}
}
回答by tambascot
I like Soley's modifications, but his code relies on an external library, and I'm not sure where he got it from, so I re-wrote it so that you don't need the TableUtil class...
我喜欢 Soley 的修改，但是他的代码依赖于一个外部库，而且我不确定他从哪里得到它，所以我重新编写了它以便您不需要 TableUtil 类......
@Override
public boolean importData(TransferHandler.TransferSupport info) {
JTable target = (JTable) info.getComponent();
JTable.DropLocation dl = (JTable.DropLocation) info.getDropLocation();
int index = dl.getRow();
int max = table.getModel().getRowCount();
if (index < 0 || index > max) {
index = max;
}
target.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
try {
Integer rowFrom = (Integer) info.getTransferable().getTransferData(localObjectFlavor);
if (rowFrom != -1 && rowFrom != index) {
int[] rows = table.getSelectedRows();
int iter = 0;
for (int row : rows) {
if (index > row) {
index--;
((Reorderable) table.getModel()).reorder(row - iter, index);
}
else {
((Reorderable) table.getModel()).reorder(row, index);
}
index++;
iter++;
}
target.getSelectionModel().addSelectionInterval(index, index);
return true;
}
} catch (Exception e) {
String error = e.getMessage();
JOptionPane.showMessageDialog(null, error, "Error", JOptionPane.ERROR_MESSAGE);
}
return false;
}
