public DataTable GetDataTable(List <T> items)
{
DataTable dt = null;
try
{
// Build a table schema from the first element in the collection
if (items != null && items.Count > 0)
{
dt = this.ConstructDataTableSchema(items[0]);
}
}
catch (IndexOutOfRangeException ex)
{
throw (new ApplicationException(
"Cannot convert List of zero length to a " +
"DataTable", ex));
}
// If the container is not convertable than throw an
// ApplicationException.
if (dt != null)
{
// Create a new row for every item in the collection and fill it.
for (int i = 0; i < items.Count; i++)
{
DataRow dr = dt.NewRow();
Type type = items[i].GetType();
MemberInfo[] members = type.GetProperties();
foreach (MemberInfo member in members)
{
object[] attributes = member.GetCustomAttributes(true);
if (attributes.Length != 0)
{
foreach (object attribute in attributes)
{
ConversionAttribute ca = attribute as
ConversionAttribute;
if (ca != null)
{
if (ca.DataTableConversion)
{
string[] nameArray
= member.Name.ToString().Split(
Convert.ToChar(" "));
PropertyInfo prop = type.GetProperty(
nameArray[0]);
if (prop.GetValue(items[i], null) != null)
{
Type valueType = prop.GetValue(items[i],
null).GetType();
dr[nameArray[0]] = prop.GetValue(items[i], null);
}
else
{
dr[nameArray[0]] = "";
}
}
}
}
}
}
dt.Rows.Add(dr);
}
return(dt);
}
else
{
Debug.WriteLine("List items不能被转换.");
//throw new ApplicationException("List items are not convertable.");
return(null);
}
}
// This method reads the attributes of your container class via
// reflection in order to build a schema for the DataTable that you
// will explicitly convert to.
private DataTable ConstructDataTableSchema(T item)
{
string tableName = string.Empty;
List <DTConverterContainer> schemaContainers = new List <DTConverterContainer>();
Type type = item.GetType();
MemberInfo[] members = type.GetProperties();
foreach (MemberInfo member in members)
{
object[] attributes = member.GetCustomAttributes(true);
if (attributes.Length != 0)
{
foreach (object attribute in attributes)
{
ConversionAttribute ca = attribute as ConversionAttribute;
if (ca != null)
{
if (ca.DataTableConversion)
{
// The name of the container class is used to name
// your DataTable
string[] classNameArray =
member.ReflectedType.ToString().Split(
Convert.ToChar("."));
tableName = classNameArray[classNameArray.Length - 1];
string name = member.Name.ToString();
PropertyInfo prop = type.GetProperty(name);
if (prop.GetValue(item, null) != null)
{
Type valueType = prop.GetValue(item, null).GetType();
// Each property that is will be a column in our
// DataTable.
schemaContainers.Add(new DTConverterContainer(name,
valueType, ca.AllowDbNull, ca.KeyField));
}
else
{
schemaContainers.Add(new DTConverterContainer(name,
typeof(string), ca.AllowDbNull, ca.KeyField));
}
}
}
}
}
}
if (schemaContainers.Count > 0)
{
DataTable dataTable = new DataTable(tableName);
DataColumn[] dataColumn = new DataColumn[schemaContainers.Count];
// Counts the number of keys that will need to be created
int totalNumberofKeys = 0;
foreach (DTConverterContainer container in schemaContainers)
{
if (container.IsKey == true && m_enforceKeys == true)
{
totalNumberofKeys = totalNumberofKeys + 1;
}
}
// Builds the DataColumns for our DataTable
DataColumn[] keyColumnArray = new DataColumn[totalNumberofKeys];
int keyColumnIndex = 0;
for (int i = 0; i < schemaContainers.Count; i++)
{
dataColumn[i] = new DataColumn();
dataColumn[i].DataType = schemaContainers[i].PropertyType;
dataColumn[i].ColumnName = schemaContainers[i].PropertyName;
dataColumn[i].AllowDBNull = schemaContainers[i].AllowDbNull;
dataTable.Columns.Add(dataColumn[i]);
if (schemaContainers[i].IsKey == true &&
m_enforceKeys == true)
{
keyColumnArray[keyColumnIndex] = dataColumn[i];
keyColumnIndex = keyColumnIndex + 1;
}
}
if (m_enforceKeys)
{
dataTable.PrimaryKey = keyColumnArray;
}
return(dataTable);
}
return(null);
}
