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
}