Flex DataGrid Column Width

Question

In my flex app I store the widths and visiblility of columns in an xml file. When the app loads it reads from the xml file and sets he columns values as applicable:

for(i = 0; i < columnsOrder.length; i++){
    newOrder[i] = myDG.columns[Number(columnsOrder[i]) - 1];
    newOrder[i].visible = (Number(columnsVisiblity[i]) == 1);
    newOrder[i].width = Number(columnsWidth[i]);
}
myDG.columns = newOrder;
myDG.invalidateList();

The problem appears to be setting the visibility (it sets the visible field correctly but messes up the width)... I've tried setting it after setting the width (outside of the loop) and before the loop as well. It resizes the columns properly if I don't do anything with the visibility.

Any ideas?

Answer 1

Add an import statement at the top of your class file:

import mx.core.mx_internal;

Then remove using the mx_internal namespace, remove the owner of the column, change the width and then reasign the parent:

public static function resizeColumn(col:DataGridColumn, size:int):void
    {
        var owner:* = col.mx_internal::owner
        col.mx_internal::owner = null;

        col.width = size;

        col.mx_internal::owner = owner;
    }

This ought to do the trick (well, it did for us after a couple of days of swearing)

Answer 2

Is you horizontalScrollPolicy set to false on the datagrid?

"If the DataGrid's horizontalScrollPolicy property is false, all visible columns must fit in the displayable area, and the DataGrid will not always honor the width of the columns if the total width of the columns is too small or too large for the displayable area."

http://livedocs.adobe.com/flex/3/langref/mx/controls/dataGridClasses/DataGridColumn.html#width

Answer 3

I was able to get it to work by calling the above loop in a function twice... the first time it add the visible columns, the second time it sets the correct width. Not the best solution but I cannot spend any more time on it.