/// <summary>

    /// 根据行数据，自动调整DataGridView高度

    /// </summary>

    public sealed partial class AutoResizeGrid

    {

        private readonly DataGridView DataGrid;

        private readonly int MaxHeight;

        /// <summary>

        /// 是否自动调整

        /// </summary>

        private bool IsAutoResize = true;

        /// <summary>

        /// 构造函数

        /// </summary>

        /// <param name="dataGridView"></param>

        /// <param name="maxHeight">最大高度，-1 时不限制高度</param>

        public AutoResizeGrid(DataGridView dataGridView, int maxHeight = -1)

        {

            this.DataGrid = dataGridView;

            this.MaxHeight = maxHeight;

            if (this.IsAutoResize)

            {

                this.DataGrid.RowsAdded += DataGrid_RowsAdded;

            }

        }

        /// <summary>

        /// 行添加后事件

        /// </summary>

        /// <param name="sender"></param>

        /// <param name="e"></param>

        private void DataGrid_RowsAdded(object sender, DataGridViewRowsAddedEventArgs e)

        {

            this.UpdateGridHeight();

        }

        /// <summary>

        /// 计算实际高度

        /// </summary>

        /// <returns></returns>

        public int GetFactHeight()

        {

            // 计算实际高度

            var rowsHeight = this.DataGrid.Rows.GetRowsHeight(DataGridViewElementStates.Visible);

            var headHeight = this.DataGrid.ColumnHeadersHeight;

            return (rowsHeight + headHeight);

        }

        /// <summary>

        /// 更新高度，调用时机，添加数据行后调用

        /// </summary>

        private void UpdateGridHeight()

        {

            // 计算实际高度

            // 多增加一行，否则会有滚动条

            var factHeight = this.GetFactHeight() + this.GetHScrollBarHeight();

            if (-1 == this.MaxHeight)

            {

                this.DataGrid.Height = factHeight;

            }

            else

            {

                this.DataGrid.Height = Math.Min(this.MaxHeight, factHeight);

            }

        }

        /// <summary>

        /// 获取水平滚动条高度

        /// </summary>

        /// <returns></returns>

        private int GetHScrollBarHeight()

        {

            var height = 2;

            foreach (Control ctrl in this.DataGrid.Controls)

            {

                if (ctrl.AccessibilityObject.ToString().IndexOf("System.Windows.Forms.HScrollBar") > 0)

                {

                    if (ctrl.Visible)

                    {

                        // do something

                        return (height + ctrl.Height);

                    }

                }

            }

            return height;

        }

    }

new AutoResizeGrid(this.dataGridView1, maxHeight: 200);