[Winform] DataGridView辅助类

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Windows.Forms;

namespace Dxq.Foundation.Forms
{
    /// <summary>
    ///     DataGridView助手.
    /// </summary>
    public class DataGridViewAssistant
    {
        /// <summary>
        ///     DataGridView
        /// </summary>
        private readonly DataGridView _dgv;

        /// <summary>
        ///     是否已经添加校验行为
        /// </summary>
        private bool _addEditBehaviored;

        /// <summary>
        ///     当前编辑时原始的值
        /// </summary>
        private object _editOldValue;

        /// <summary>
        ///     是否已经添加过显示行号行为
        /// </summary>
        private bool _showRowNumed;

        /// <summary>
        ///     校验规则集合
        /// </summary>
        private Dictionary<int, Func<int, object, bool>> _validationRules;

        /// <summary>
        ///     校验成功时需要执行的方法
        /// </summary>
        private Action<int, int> _validationSucceedAction;

        /// <summary>
        ///     初始化<see cref="DataGridViewAssistant" /> 类的新实例.
        /// </summary>
        /// <param name="dgv">DataGridView控件.</param>
        /// <exception cref="ArgumentNullException">dgv</exception>
        public DataGridViewAssistant(DataGridView dgv)
        {
            if (dgv == null)
            {
                throw new ArgumentNullException(nameof(dgv));
            }

            _dgv = dgv;

            _dgv.AutoGenerateColumns = false;
        }

        /// <summary>
        ///     添加在编辑时的校验行为.
        /// </summary>
        /// <returns>DataGridViewAssistant.</returns>
        public DataGridViewAssistant AddValidationBehavior()
        {
            if (_addEditBehaviored)
            {
                return this;
            }

            _validationRules = new Dictionary<int, Func<int, object, bool>>();

            _dgv.CellBeginEdit += DgvOnCellBeginEdit;
            _dgv.CellEndEdit   += DgvOnCellEndEdit;

            _addEditBehaviored = true;

            return this;
        }

        /// <summary>
        ///     显示行号.
        /// </summary>
        /// <returns>DataGridViewAssistant.</returns>
        public DataGridViewAssistant ShowRowNum()
        {
            if (_showRowNumed)
            {
                return this;
            }

            _dgv.RowsAdded   += (sender, args) => { ShowRowNumAction(); };
            _dgv.RowsRemoved += (sender, args) => { ShowRowNumAction(); };

            _showRowNumed = true;

            return this;
        }

        /// <summary>
        ///     添加单元格编辑校验规则.
        /// </summary>
        /// <param name="columnIndex">Index of the column.</param>
        /// <param name="ruleFunc">The rule function.</param>
        /// <returns>DataGridViewAssistant.</returns>
        public DataGridViewAssistant AddCellEditValidationRule(int columnIndex, Func<int, object, bool> ruleFunc)
        {
            if (_validationRules.ContainsKey(columnIndex))
            {
                return this;
            }

            _validationRules.Add(columnIndex, ruleFunc);

            return this;
        }

        /// <summary>
        ///     Adds the validation succeed.
        /// </summary>
        /// <param name="action">The action.</param>
        /// <returns>DataGridViewAssistant.</returns>
        public DataGridViewAssistant AddValidationSucceed(Action<int, int> action)
        {
            if (action == null)
            {
                throw new ArgumentNullException(nameof(action));
            }

            _validationSucceedAction = action;

            return this;
        }

        /// <summary>
        ///     单元格编辑开始时触发的事件.
        /// </summary>
        /// <param name="sender">发生源.</param>
        /// <param name="e">包含事件数据的<see cref="DataGridViewCellCancelEventArgs" />实例。</param>
        private void DgvOnCellBeginEdit(object sender, DataGridViewCellCancelEventArgs e)
        {
            // 预存旧值,进行验证失败后进行回撤.
            _editOldValue = _dgv.Rows[e.RowIndex].Cells[e.ColumnIndex].Value;
        }

        /// <summary>
        ///     单元格编辑结束时触发的事件.
        /// </summary>
        /// <param name="sender">发生源.</param>
        /// <param name="e">包含事件数据的<see cref="DataGridViewCellEventArgs" /> 实例。</param>
        private void DgvOnCellEndEdit(object sender, DataGridViewCellEventArgs e)
        {
            if (_dgv.Columns[e.ColumnIndex].GetType().Name != typeof(DataGridViewTextBoxColumn).Name)
            {
                return; //  其他情况值都是语言设定的 不进行校验
            }

            if (_validationRules.ContainsKey(e.ColumnIndex))
            {
                if (!_validationRules[e.ColumnIndex](e.RowIndex, _dgv.Rows[e.RowIndex].Cells[e.ColumnIndex].Value))
                {
                    _dgv.Rows[e.RowIndex].Cells[e.ColumnIndex].Value = _editOldValue;

                    return;
                }
            }

            _validationSucceedAction?.Invoke(e.RowIndex, e.ColumnIndex);
        }

        /// <summary>
        ///     显示行号具体的执行方法.
        /// </summary>
        private void ShowRowNumAction()
        {
            for (var i = 0; i < _dgv.Rows.Count; i++)
            {
                _dgv.Rows[i].HeaderCell.Value = (i + 1).ToString(CultureInfo.InvariantCulture);
            }
        }
    }
}