Auto resizing the JTable column widths

问题

I need my JTable to automatically re-size its column widths to fit the content. I found the TableColumnAdjuster class very useful. But there\'s a small problem. Say i have 5 columns, and their content is very short. In that case, if i use the auto adjuster, it sets the first four columns widths according to their content and gives all the rest of space to the last column. Please see the example.

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Here the last column, Balance is given all the excess space. But what if i need to give that space to one of the middle columns. In the above case, i need to assign that space to the third column, name. I tried modifying the TableColumnAdjuster class\'s adjustColumns() method. But I couldn\'t get it working.

I tried both column.setPreferredWidth() and column.setWidth() for changing column sizes. But seems it doesn\'t change anything. How can I effectively change the column sizes of a JTable. If there\'s some other alternative or a direct answer to my main problem, that\'s better. Thanks!

回答1:

You can try the next:

public void resizeColumnWidth(JTable table) {
    final TableColumnModel columnModel = table.getColumnModel();
    for (int column = 0; column < table.getColumnCount(); column++) {
        int width = 15; // Min width
        for (int row = 0; row < table.getRowCount(); row++) {
            TableCellRenderer renderer = table.getCellRenderer(row, column);
            Component comp = table.prepareRenderer(renderer, row, column);
            width = Math.max(comp.getPreferredSize().width +1 , width);
        }
        if(width > 300)
            width=300;
        columnModel.getColumn(column).setPreferredWidth(width);
    }
}

This needs to be executed before the resize method.
If you have:

table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);

回答2:

There is no option to automatically resize one column larger than the other.

Maybe you can to something like:

tca = new TableColumnAdjuster( table, 0 );
tca.adjustColumns();
TableColumnModel tcm = table.getColumnModel();  
TableColumn tc = tcm.getColumn(1);
tc.setWidth(tc.getWidth() + 25);

This would allow you to add extra space to column 1. This extra space would only be added the first time the table is displayed.

Another option is to use:

table.setAutoResizeMode(JTable.AUTO_RESIZE_ALL_COLUMNS);

This would allocate extra space proportionally to each column.

回答3:

setAutoResizeMode() will tell your table how to resize you should give it a try will all different options available to see the differences, in My case I wanted to specifically resize two columns and let it decide how to adjust all the other ones.

jTable1.setAutoResizeMode(JTable.AUTO_RESIZE_NEXT_COLUMN);
TableColumnModel colModel=jTable1.getColumnModel();
colModel.getColumn(1).setPreferredWidth(25);    
colModel.getColumn(2).setPreferredWidth(400);

回答4:

You can do this:

JPanel jp = new JPanel();
jp.add(table);

jp.setLayout(new GridLayout(1,1)); /* little trick ;) and believe me that this step is important to the automatic all columns resize! A import is also needed for using GridLayout*/
table.setAutoResizeMode(JTable.AUTO_RESIZE_ALL_COLUMNS); // this is obvius part

来源：https://stackoverflow.com/questions/17627431/auto-resizing-the-jtable-column-widths

标签

java

swing

jtable

tablecolumn