Java JTable setting Column Width

问题:

I have a JTable in which I set the column size as follows:

table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
table.getColumnModel().getColumn(0).setPreferredWidth(27);
table.getColumnModel().getColumn(1).setPreferredWidth(120);
table.getColumnModel().getColumn(2).setPreferredWidth(100);
table.getColumnModel().getColumn(3).setPreferredWidth(90);
table.getColumnModel().getColumn(4).setPreferredWidth(90);
table.getColumnModel().getColumn(6).setPreferredWidth(120);
table.getColumnModel().getColumn(7).setPreferredWidth(100);
table.getColumnModel().getColumn(8).setPreferredWidth(95);
table.getColumnModel().getColumn(9).setPreferredWidth(40);
table.getColumnModel().getColumn(10).setPreferredWidth(400);

This works fine, but when the table is maximized, I get empty space to the right of the last column. Is it possible to make the last column resize to the end of the window when resized?

I found AUTO_RESIZE_LAST_COLUMN property in docs but it does not work.

Edit: JTable is in a JScrollPane its prefered size is set.

回答1:

What happens if you call setMinWidth(400) on the last column instead of setPreferredWidth(400)?

In the JavaDoc for JTable, read the docs for doLayout() very carefully. Here are some choice bits:

When the method is called as a result of the resizing of an enclosing window, the resizingColumn is null. This means that resizing has taken place "outside" the JTable and the change - or "delta" - should be distributed to all of the columns regardless of this JTable's automatic resize mode.

This might be why AUTO_RESIZE_LAST_COLUMN didn't help you.

Note: When a JTable makes adjustments to the widths of the columns it respects their minimum and maximum values absolutely.

This says that you might want to set Min == Max for all but the last columns, then set Min = Preferred on the last column and either not set Max or set a very large value for Max.

回答2:

With JTable.AUTO_RESIZE_OFF, the table will not change the size of any of the columns for you, so it will take your preferred setting. If it is your goal to have the columns default to your preferred size, except to have the last column fill the rest of the pane, You have the option of using the JTable.AUTO_RESIZE_LAST_COLUMN autoResizeMode, but it might be most effective when used with TableColumn.setMaxWidth() instead of TableColumn.setPreferredWidth() for all but the last column.

Once you are satisfied that AUTO_RESIZE_LAST_COLUMN does in fact work, you can experiment with a combination of TableColumn.setMaxWidth() and TableColumn.setMinWidth()

回答3:

JTable.AUTO_RESIZE_LAST_COLUMN is defined as "During all resize operations, apply adjustments to the last column only" which means you have to set the autoresizemode at the end of your code, otherwise setPreferredWidth() won't affect anything!

So in your case this would be the correct way:

table.getColumnModel().getColumn(0).setPreferredWidth(27);
table.getColumnModel().getColumn(1).setPreferredWidth(120);
table.getColumnModel().getColumn(2).setPreferredWidth(100);
table.getColumnModel().getColumn(3).setPreferredWidth(90);
table.getColumnModel().getColumn(4).setPreferredWidth(90);
table.getColumnModel().getColumn(6).setPreferredWidth(120);
table.getColumnModel().getColumn(7).setPreferredWidth(100);
table.getColumnModel().getColumn(8).setPreferredWidth(95);
table.getColumnModel().getColumn(9).setPreferredWidth(40);
table.getColumnModel().getColumn(10).setPreferredWidth(400);
table.setAutoResizeMode(JTable.AUTO_RESIZE_LAST_COLUMN);

回答4:

Use this method

public static void setColumnWidths(JTable table, int... widths) {
    TableColumnModel columnModel = table.getColumnModel();
    for (int i = 0; i < widths.length; i++) {
        if (i < columnModel.getColumnCount()) {
            columnModel.getColumn(i).setMaxWidth(widths[i]);
        }
        else break;
    }

Or extend the JTable class:

public class Table extends JTable {
    public void setColumnWidths(int... widths) {
        for (int i = 0; i < widths.length; i++) {
            if (i < columnModel.getColumnCount()) {
                columnModel.getColumn(i).setMaxWidth(widths[i]);
            }
            else break;
        }
    }
}

And then

table.setColumnWidths(30, 150, 100, 100);

回答5:

Reading the remark of Kleopatra (her 2nd time she suggested to have a look at javax.swing.JXTable, and now I Am sorry I didn't have a look the first time :) ) I suggest you follow the link

I had this solution for the same problem: (but I suggest you follow the link above) On resize the table, scale the table column widths to the current table total width. to do this I use a global array of ints for the (relative) column widths):

private int[] columnWidths=null;

I use this function to set the table column widths:

public void setColumnWidths(int[] widths){
    int nrCols=table.getModel().getColumnCount();
    if(nrCols==0||widths==null){
        return;
    }
    this.columnWidths=widths.clone();

    //current width of the table:
    int totalWidth=table.getWidth();

    int totalWidthRequested=0;
    int nrRequestedWidths=columnWidths.length;
    int defaultWidth=(int)Math.floor((double)totalWidth/(double)nrCols);

    for(int col=0;col<nrCols;col++){
        int width = 0;
        if(columnWidths.length>col){
            width=columnWidths[col];
        }
        totalWidthRequested+=width;
    }
    //Note: for the not defined columns: use the defaultWidth
    if(nrRequestedWidths<nrCols){
        log.fine("Setting column widths: nr of columns do not match column widths requested");
        totalWidthRequested+=((nrCols-nrRequestedWidths)*defaultWidth);
    }
    //calculate the scale for the column width
    double factor=(double)totalWidth/(double)totalWidthRequested;

    for(int col=0;col<nrCols;col++){
        int width = defaultWidth;
        if(columnWidths.length>col){
            //scale the requested width to the current table width
            width=(int)Math.floor(factor*(double)columnWidths[col]);
        }
        table.getColumnModel().getColumn(col).setPreferredWidth(width);
        table.getColumnModel().getColumn(col).setWidth(width);
    }

}

When setting the data I call:

    setColumnWidths(this.columnWidths);

and on changing I call the ComponentListener set to the parent of the table (in my case the JScrollPane that is the container of my table):

public void componentResized(ComponentEvent componentEvent) {
    this.setColumnWidths(this.columnWidths);
}

note that the JTable table is also global:

private JTable table;

And here I set the listener:

    scrollPane=new JScrollPane(table);
    scrollPane.addComponentListener(this);

回答6:

fireTableStructureChanged();

will default the resize behavior ! If this method is called somewhere in your code AFTER you did set the column resize properties all your settings will be reset. This side effect can happen indirectly. F.e. as a consequence of the linked data model being changed in a way this method is called, after properties are set.

回答7:

Use this code. It worked for me. I considered for 3 columns. Change the loop value for your code.

TableColumn column = null;
        for (int i = 0; i < 3; i++) {
            column = table.getColumnModel().getColumn(i);
            if (i == 0) 
                column.setMaxWidth(10);
            if (i == 2)
                column.setMaxWidth(50);
        }