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  • DataTable与实体类互相转换

    /// <summary>
    /// DataTable与实体类互相转换
    /// </summary>
    /// <typeparam name="T">实体类</typeparam>
    public class ModelHandler<T> where T : new()
    {
    #region DataTable转换成实体类

    /// <summary>
    /// 填充对象列表:用DataSet的第一个表填充实体类
    /// </summary>
    /// <param name="ds">DataSet</param>
    /// <returns></returns>
    public List<T> FillModel(DataSet ds)
    {
    if (ds == null || ds.Tables[0] == null || ds.Tables[0].Rows.Count == 0)
    {
    return null;
    }
    else
    {
    return FillModel(ds.Tables[0]);
    }
    }

    /// <summary>
    /// 填充对象列表:用DataSet的第index个表填充实体类
    /// </summary>
    public List<T> FillModel(DataSet ds, int index)
    {
    if (ds == null || ds.Tables.Count <= index || ds.Tables[index].Rows.Count == 0)
    {
    return null;
    }
    else
    {
    return FillModel(ds.Tables[index]);
    }
    }

    /// <summary>
    /// 填充对象列表:用DataTable填充实体类
    /// </summary>
    public List<T> FillModel(DataTable dt)
    {
    if (dt == null || dt.Rows.Count == 0)
    {
    return null;
    }
    List<T> modelList = new List<T>();
    foreach (DataRow dr in dt.Rows)
    {
    //T model = (T)Activator.CreateInstance(typeof(T));
    T model = new T();
    for (int i = 0; i < dr.Table.Columns.Count; i++)
    {
    PropertyInfo propertyInfo = model.GetType().GetProperty(dr.Table.Columns[i].ColumnName);
    if (propertyInfo != null && dr[i] != DBNull.Value)
    propertyInfo.SetValue(model, dr[i], null);
    }

    modelList.Add(model);
    }
    return modelList;
    }

    /// <summary>
    /// 填充对象:用DataRow填充实体类
    /// </summary>
    public T FillModel(DataRow dr)
    {
    if (dr == null)
    {
    return default(T);
    }

    //T model = (T)Activator.CreateInstance(typeof(T));
    T model = new T();

    for (int i = 0; i < dr.Table.Columns.Count; i++)
    {
    PropertyInfo propertyInfo = model.GetType().GetProperty(dr.Table.Columns[i].ColumnName);
    if (propertyInfo != null && dr[i] != DBNull.Value)
    propertyInfo.SetValue(model,dr[i],null);
    }
    return model;
    }

    #endregion

    #region 实体类转换成DataTable

    /// <summary>
    /// 实体类转换成DataSet
    /// </summary>
    /// <param name="modelList">实体类列表</param>
    /// <returns></returns>
    public DataSet FillDataSet(List<T> modelList)
    {
    if (modelList == null || modelList.Count == 0)
    {
    return null;
    }
    else
    {
    DataSet ds = new DataSet();
    ds.Tables.Add(FillDataTable(modelList));
    return ds;
    }
    }

    /// <summary>
    /// 实体类转换成DataTable
    /// </summary>
    /// <param name="modelList">实体类列表</param>
    /// <returns></returns>
    public DataTable FillDataTable(List<T> modelList)
    {
    if (modelList == null || modelList.Count == 0)
    {
    return null;
    }
    DataTable dt = CreateData(modelList[0]);

    foreach(T model in modelList)
    {
    DataRow dataRow = dt.NewRow();
    foreach (PropertyInfo propertyInfo in typeof(T).GetProperties())
    {
    dataRow[propertyInfo.Name] = propertyInfo.GetValue(model, null);
    }
    dt.Rows.Add(dataRow);
    }
    return dt;
    }

    /// <summary>
    /// 根据实体类得到表结构
    /// </summary>
    /// <param name="model">实体类</param>
    /// <returns></returns>
    private DataTable CreateData(T model)
    {
    DataTable dataTable = new DataTable(typeof (T).Name);
    foreach (PropertyInfo propertyInfo in typeof(T).GetProperties())
    {
    dataTable.Columns.Add(new DataColumn(propertyInfo.Name, propertyInfo.PropertyType));
    }
    return dataTable;
    }

    #endregion
    }

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  • 原文地址:https://www.cnblogs.com/yang_mysky/p/4042936.html
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