DataGrid, Auto- resize the datagrid based on content

Using the Code

Syntax

Calling this method is very straightforward. It takes only two parameters:

public void SizeColumnsToContent(DataGrid dataGrid,
                                int nRowsToScan)

• dataGrid—The DataGrid object to be resized
• nRowsToScan—The number of rows to scan when searching for the widest value for a given column. Passing a value of -1 indicates that all rows should be scanned.

SizeColumnsToContent Method

public void SizeColumnsToContent(DataGrid dataGrid,
      int nRowsToScan)
{
 // Create graphics object for measuring widths.
 Graphics Graphics = dataGrid.CreateGraphics();

 // Define new table style.
 DataGridTableStyle tableStyle = new DataGridTableStyle();

 try
 {
   DataTable dataTable = (DataTable)dataGrid.DataSource;

   if (-1 == nRowsToScan)
   {
     nRowsToScan = dataTable.Rows.Count;
   }
   else
   {
     // Can only scan rows if they exist.
     nRowsToScan = System.Math.Min(nRowsToScan,
                   dataTable.Rows.Count);
   }

   // Clear any existing table styles.
   dataGrid.TableStyles.Clear();

   // Use mapping name that is defined in the data source.
   tableStyle.MappingName = dataTable.TableName;

   // Now create the column styles within the table style.
   DataGridTextBoxColumn columnStyle;
   int iWidth;

   for (int iCurrCol = 0;
        iCurrCol < dataTable.Columns.Count; iCurrCol++)
   {
     DataColumn dataColumn = dataTable.Columns[iCurrCol];

     columnStyle = new DataGridTextBoxColumn();

     columnStyle.TextBox.Enabled = true;
     columnStyle.HeaderText = dataColumn.ColumnName;
     columnStyle.MappingName = dataColumn.ColumnName;

     // Set width to header text width.
     iWidth = (int)(Graphics.MeasureString
                   (columnStyle.HeaderText,
                    dataGrid.Font).Width);

     // Change width, if data width is
     // wider than header text width.
     // Check the width of the data in the first X rows.
     DataRow dataRow;
     for (int iRow = 0; iRow < nRowsToScan; iRow++)
     {
       dataRow = dataTable.Rows[iRow];

       if (null != dataRow[dataColumn.ColumnName])
       {
         int iColWidth = (int)(Graphics.MeasureString
                         (dataRow.ItemArray[iCurrCol].ToString(),
                          dataGrid.Font).Width);
         iWidth = (int)System.Math.Max(iWidth, iColWidth);
       }
     }
     columnStyle.Width = iWidth + 4;

     // Add the new column style to the table style.
     tableStyle.GridColumnStyles.Add(columnStyle);
   }
   // Add the new table style to the data grid.
   dataGrid.TableStyles.Add(tableStyle);
 }
 catch(Exception e)
 {
   MessageBox.Show(e.Message);
 }
 finally
 {
   Graphics.Dispose();
 }
}