ASP.net/C# newbie looking for help editing column width dynamically when data is retrieved

Question

I've been messing around with this and have yet to find a clean solution. At the moment, I have a asp:DataGrid control on the aspx page (I am open to changing this). When I click a button, I retrieve a DataSet from a database and use a DataTable from the DataSet to fill up my DataGrid.

If my asp:DataGrid is named "tableData" and my DataSet is named data the following implementation will fill my grid successfully:

protected void renderData(object sender, EventArgs e)
{
DataSet data = hc.getDataSet();

tableData.DataSource = data.Tables[0];
tableData.DataBind();
}

But my column widths are not as wide as desired. I would like to look at all the data in each column of data.Tables[0] and choose my tableData column's widths accordingly.

I have tried many ways of accomplishing this and failed but here are my two main ideas and the problems I've encountered:

Solution 1: Alter column width after the DataBind(). I would use some type of code along the lines of

tableData.Columns[i].ItemStyle.Width = longestField;

The problem with this solution is the DataBind() seems to not have taken place yet and I get some null pointer like exceptions. I could do it after, but how would I know when it is done? Even if there was some event like AfterDataBind I would prefer not to use it because if I would have to determine what table I was dealing with in that particular function.

Solution 2: Create my own databind method and use that instead

The problem with this solution is I can't seem to add rows to tableData myself (I would expect something like a tableData.NewRow() function but I can't seem to find one fitting my needs.

I have also tried using OnDataItemBound function, but I realized I have know idea how to relate the DataGridItemEventArgs e back to datagrid's column collection.

I would appreciate some insight. Thanks in advance guys.

Answer 1

Calculating column widths is a tricky business, and is prone to glitches. I would suggest setting fixed widths for columns with a limited amount of data, and let the grid use percentage widths for the other columns.

For example, let's say you have a list of addresses.

• Zip code should be less than 10 digits, so around 80px should be sufficient
• City is not as limited, but 200px will probably do the trick
• Street address could be really short or really long, so use a percentage width

If you're dead-set on calculating the column widths, take a look at this article:

http://www.syncfusion.com/FAQ/WindowsForms/FAQ_c44c.aspx#q877q