GridControl Linq

1. 新增数据

GridView的NewItemRowPosition属性设置为Bottom

代码：

List<ObjectType> DetailCollection { get; set; }
private void XXXForm_Load(object sender, EventArgs e) {
    DetailCollection = new List<ObjectType>();
}
private void gvDataView_CustomRowCellEditForEditing(object sender, CustomRowCellEditEventArgs e) {
    if (e.RowHandle < 0) { //新增数据
        DetailCollection.Add(new ObjectType() { AutoID = 0 });
        gvDataView.RefreshData();
        gvDataView.FocusedRowHandle = DetailCollection.Count - 1;
    }
}
// 删除行
private void gvDataView_KeyUp(object sender, KeyEventArgs e) {
    if (e.KeyCode == Keys.Delete && this.gvDataView.FocusedRowHandle >= 0) {
        int index = gvDataView.FocusedRowHandle;
        if (MessageBoxHelper.ShowConfirm("删除不可恢复,是否确定删除？") == DialogResult.OK) {
            DetailCollection.RemoveAt(index);
            gvDataView.RefreshData();
            gvDataView.FocusedRowHandle = DetailCollection.Count > index ? index : -1;
        }
    }
}

 2. 编辑数据

GridControl可绑定Linq查询的匿名类型结果集，但是不可编辑。

代码：

var ds = from xc in XXXCollection
         where ......
         select new {
             ACol = xc.XXX,
             BCol = xc.YYY,
         };
gcDataCtrl.DataSource = ds.ToArray();

注：在绑定的时候，需要结果集ds转换一下，ToArray()/ToList()都可以。

绑定显示不会有问题，但是在编辑的时候就会出现编辑不了的情况。

GridControl不支持匿名类型的编辑，需要将结果集转换一下，这里转换成了DataTable类型。

代码：

var ds = from xc in XXXCollection
         where ......
         select new {
             ACol = xc.XXX,
             BCol = xc.YYY,
         };
gcDataCtrl.DataSource = ds.ConvertToDataTable();

系统库是没有这个函数的，所有需要使用扩展方法。

代码：

using System;
using System.Collections.Generic;
using System.Data;
using System.Reflection;

namespace ManageSystem.Common {
    public static class ClassExtension {
        #region "Convert Generic List to DataTable"
        /// <summary>
        /// Convert a List{T} to a DataTable.
        /// </summary>
        public static DataTable ConvertToDataTable<T>(this IEnumerable<T> items) {
            var tb = new DataTable(typeof(T).Name);
            PropertyInfo[] props = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);

            foreach (PropertyInfo prop in props) {
                Type t = GetCoreType(prop.PropertyType);
                tb.Columns.Add(prop.Name, t);
            }

            foreach (T item in items) {
                var values = new object[props.Length];

                for (int i = 0; i < props.Length; i++) {
                    values[i] = props[i].GetValue(item, null);
                }
                tb.Rows.Add(values);
            }
            return tb;
        }

        /// <summary>
        /// Determine of specified type is nullable
        /// </summary>
        public static bool IsNullable(Type t) {
            return !t.IsValueType || (t.IsGenericType && t.GetGenericTypeDefinition() == typeof(Nullable<>));
        }

        /// <summary>
        /// Return underlying type if type is Nullable otherwise return the type.
        /// </summary>
        public static Type GetCoreType(Type t) {
            if (t != null && IsNullable(t)) {
                if (!t.IsValueType) {
                    return t;
                }
                else {
                    return Nullable.GetUnderlyingType(t);
                }
            }
            else {
                return t;
            }
        }
        #endregion
    }
}