Option 1 - Overriding GetPreferredSize
You can override GetPreferredSize method of DataGridView and call the base method using new proposed size new Size(this.Width, proposedSize.Height). This way, the current width of control will remain untouched while the auto-size rules will apply on its height:
using System.Drawing;
using System.Windows.Forms;
public class MyDataGridView : DataGridView
{
public override Size GetPreferredSize(Size proposedSize)
{
return base.GetPreferredSize(new Size(this.Width, proposedSize.Height));
}
}
Option 2 - Setting the Height based on Height of Calculated Auto-Size
If you don't want to derive from DataGridView, you can calculate the auto-size by calling its GetPreferredSize passing new Size(0, 0) then set the height of DataGridView to the height of result, this way you only change the height of DataGridView. You should set the auto-height in RowsAdded, RowsRemoved, some other events if you need:
void AutoHeightGrid(DataGridView grid)
{
var proposedSize = grid.GetPreferredSize(new Size(0, 0));
grid.Height = proposedSize.Height;
}
private void Form1_Load(object sender, EventArgs e)
{
dataGridView1.RowsAdded += (obj, arg) => AutoHeightGrid(dataGridView1);
dataGridView1.RowsRemoved += (obj, arg) => AutoHeightGrid(dataGridView1);
//Set data source
//dataGridView1.DataSource = something;
}
If you want to make sure that all changes in grid including changing Font, height of rows will cause resizing grid, you can call the method in Paint event.
Option 3 - Setting MaximumSize
Also as mentioned by Hans, if you don't want to derive from DataGridView, you can use MaximumSize property of the grid. You can set it to new Size(this.dataGridView1.Width, 0):
dataGridView1.MaximumSize = new Size(this.dataGridView1.Width, 0);
dataGridView1.AutoSize = true;
Note
Since using MaximumSize is not so friendly when the user wants to let the grid width change by left and right anchors, I prefer to use Option 1 or Option 2.
