SANHOPE.mes.wcf/DK.Basics/InvoiceLayout/Controls/Common/LayoutBoxDataBinding.cs


using System;
using System.ComponentModel;
using System.Windows.Forms;

namespace Dongke.WinForm.Controls.InvoiceLayout
{
    internal class LayoutBoxDataBinding
    {
        #region 成员变量
        private CurrencyManager _currencyManager;                // 对象列表管理器
        private LayoutBox _owner;                                            // Layout
        private PropertyDescriptorCollection _props;                // 基本属性的描述列表集合
        private BindingSource _bindingSource;                        // 封装形式的数据源
        #endregion 成员变量

        #region 属性
        /// <summary>
        /// 获取封装形式的数据源。
        /// </summary>
        public BindingSource BindingSource
        {
            get
            {
                return _bindingSource;
            }
        }
        #endregion 属性

        #region 构造函数
        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="owner">Layout</param>
        public LayoutBoxDataBinding(LayoutBox owner)
        {
            _owner = owner;
            _bindingSource = new BindingSource();
        }
        #endregion 构造函数

        #region 函数
        #region 公共函数
        /// <summary>
        /// 清理所有正在使用的资源
        /// </summary>
        public void Dispose()
        {
            UnWireEvents();
            _currencyManager = null;
            _owner = null;
            _props = null;
            _bindingSource = null;
        }

        /// <summary>
        /// 绑定数据源到文本Item
        /// </summary>
        /// <param name="textItem">文本Item</param>
        /// <returns>
        /// true : 绑定成功
        /// false : 绑定失败
        /// </returns>
        public bool BoundFieldToTextItem(TextItem textItem)
        {
            if (textItem == null)
            {
                return false;
            }

            DataBoundField boundField = textItem.BoundField;

            boundField.IsDataBound = false;
            boundField.BoundFieldIndex = -1;

            if ((_bindingSource == null)
                || (_props == null)
                || (_bindingSource.DataSource == null))
            {
                textItem.DataValue = null;
                textItem.BoundField = boundField;
                return false;
            }

            // 获取绑定数据源的索引
            int index = GetBoundFieldIndex(textItem.DataMember);

            if (index < 0)
            {
                textItem.DataValue = null;
                textItem.BoundField = boundField;
                return false;
            }
            else
            {
                boundField.IsDataBound = true;
                boundField.BoundFieldIndex = index;
                boundField.BoundFieldConverter = _props[index].Converter;
                boundField.ValueType = _props[index].PropertyType;
                textItem.BoundField = boundField;
                // 获取数据源中的值
                textItem.DataValue = GetValue(textItem, _bindingSource.Position);
                return true;
            }
        }

        /// <summary>
        /// 设置数据源的值到文本Item中
        /// </summary>
        /// <param name="textItem">文本Item</param>
        /// <returns>
        /// true : 设置成功
        /// false : 设置失败
        /// </returns>
        public bool BoundDataValueToTextItem(TextItem textItem)
        {
            if (textItem == null)
            {
                return false;
            }

            if ((!textItem.BoundField.IsDataBound)
                || (textItem.BoundField.BoundFieldIndex < 0)
                || (_props == null))
            {
                textItem.DataValue = null;
                return false;
            }

            textItem.DataValue = GetValue(textItem, _bindingSource.Position);

            return true;
        }

        /// <summary>
        /// 绑定数据连接设置
        /// </summary>
        /// <param name="dataSource">数据源</param>
        /// <param name="dataMember">数据源列表的名称</param>
        public void SetDataConnection(object dataSource, string dataMember)
        {
            // 卸载事件
            UnWireEvents();

            if (dataMember == null)
            {
                dataMember = string.Empty;
            }

            _bindingSource.DataSource = dataSource;
            _bindingSource.DataMember = dataMember;
            _currencyManager = _bindingSource.CurrencyManager;
            if (_currencyManager != null)
            {
                _props = _currencyManager.GetItemProperties();
            }
            else
            {
                _props = null;
            }
            // 加载事件
            WireEvents();
        }

        /// <summary>
        /// 成员是否包含在数据源中
        /// </summary>
        /// <param name="newDataSource">数据源</param>
        /// <returns>
        /// true : 包含
        /// false : 不包含
        /// </returns>
        public bool ContainsDataMember(object newDataSource)
        {
            if (newDataSource != null)
            {
                if (_currencyManager == null || _props == null)
                {
                    return false;
                }
                if (!string.IsNullOrEmpty(_bindingSource.DataMember)
                    && _props[_bindingSource.DataMember] != null)
                {
                    return false;
                }
            }
            return true;
        }
        #endregion 公共函数

        #region  私有函数
        /// <summary>
        /// 取得绑定数据源的索引
        /// </summary>
        /// <param name="dataFieldName">数据字段名</param>
        /// <returns>
        /// -1 : 数据字段名不存在
        /// 大于-1 : 数据字段对应的索引
        /// </returns>
        private int GetBoundFieldIndex(string dataFieldName)
        {
            if (_props == null || string.IsNullOrEmpty(dataFieldName))
            {
                return -1;
            }
            for (int i = 0; i < _props.Count; i++)
            {
                if (string.Compare(_props[i].Name, dataFieldName, true,
                    System.Globalization.CultureInfo.InvariantCulture) == 0)
                {
                    return i;
                }
            }
            return -1;
        }

        /// <summary>
        /// ListChanged事件
        /// </summary>
        /// <param name="sender">指定的对象</param>
        /// <param name="e">提供的事件数据</param>
        private void bindingSource_ListChanged(object sender, ListChangedEventArgs e)
        {
            if (((e.ListChangedType == ListChangedType.PropertyDescriptorAdded)
                || (e.ListChangedType == ListChangedType.PropertyDescriptorDeleted))
                || (e.ListChangedType == ListChangedType.PropertyDescriptorChanged))
            {
                if (_currencyManager != null)
                {
                    _props = _currencyManager.GetItemProperties();
                    _owner.RefreshItemsBound();
                }
            }
            else
            {
                _owner.RefreshItems();
            }
        }

        /// <summary>
        /// PositionChanged事件
        /// </summary>
        /// <param name="sender">指定的对象</param>
        /// <param name="e">提供的事件数据</param>
        private void bindingSource_PositionChanged(object sender, EventArgs e)
        {
            _owner.RefreshItems();
        }

        /// <summary>
        /// 从数据源检索数据
        /// </summary>
        /// <param name="textItem">文本Item</param>
        /// <param name="positionIndex">索引</param>
        /// <returns>数据源中对应的数据</returns>
        private object GetValue(TextItem textItem, int positionIndex)
        {
            if (_props == null
                || _bindingSource == null
                || _bindingSource.List == null
                || positionIndex < 0)
            {
                return null;
            }

            return _props[textItem.BoundField.BoundFieldIndex].GetValue(
                _bindingSource.List[positionIndex]);
        }

        /// <summary>
        /// 卸载事件
        /// </summary>
        private void UnWireEvents()
        {
            if (_bindingSource != null)
            {
                _bindingSource.PositionChanged -=
                    new EventHandler(bindingSource_PositionChanged);
                _bindingSource.ListChanged -=
                    new ListChangedEventHandler(bindingSource_ListChanged);
            }
        }

        /// <summary>
        /// 加载事件
        /// </summary>
        private void WireEvents()
        {
            if (_bindingSource != null)
            {
                _bindingSource.PositionChanged +=
                    new EventHandler(bindingSource_PositionChanged);
                _bindingSource.ListChanged +=
                    new ListChangedEventHandler(bindingSource_ListChanged);
            }
        }
        #endregion 私有函数
        #endregion 函数
    }
}