您不能从另一个表中添加DataColumn,因为它已经与它的原始表关联并且DataColumn通过引用传递给Add方法,因为它是一个Object。你必须复制它。这里是你可以做的一个方法:
public static class DataColumnExtensions
{
public static DataColumn CopyTo(this DataColumn column, DataTable table)
{
DataColumn newColumn = new DataColumn(column.ColumnName, column.DataType, column.Expression, column.ColumnMapping);
newColumn.AllowDBNull = column.AllowDBNull;
newColumn.AutoIncrement = column.AutoIncrement;
newColumn.AutoIncrementSeed = column.AutoIncrementSeed;
newColumn.AutoIncrementStep = column.AutoIncrementStep;
newColumn.Caption = column.Caption;
newColumn.DateTimeMode = column.DateTimeMode;
newColumn.DefaultValue = column.DefaultValue;
newColumn.MaxLength = column.MaxLength;
newColumn.ReadOnly = column.ReadOnly;
newColumn.Unique = column.Unique;
table.Columns.Add(newColumn);
return newColumn;
}
public static DataColumn CopyColumnTo(this DataTable sourceTable, string columnName, DataTable destinationTable)
{
if (sourceTable.Columns.Contains(columnName))
{
return sourceTable.Columns[columnName].CopyTo(destinationTable);
}
else
{
throw new ArgumentException("The specified column does not exist", "columnName");
}
}
}
public class MyClass
{
public static void Main()
{
DataTable tableA = new DataTable("TableA");
tableA.Columns.Add("Column1", typeof(int));
tableA.Columns.Add("Column2", typeof(string));
DataTable tableB = new DataTable("TableB");
foreach (DataColumn column in tableA.Columns)
{
column.CopyTo(tableB);
}
}
}
注意,也有一个扩展方法,可以用来通过名字来单独列复制,即tableA.CopyColumnTo("Column1", tableB);
。
然后你就可以复制这样的数据如果新表是原件的精确副本:
foreach (DataRow row in tableA.Rows)
{
tableB.Rows.Add(row.ItemArray);
}
,或者以类似于第二件添Schmelter的答案代码的方式,如果它不是一个确切的副本。但是,如果您不是将所有列复制到新表格中,我会推荐一些错误检查:
foreach (DataRow souceRow in sourceTable.Rows)
{
DataRow destinationRow = destinationTable.Rows.Add();
foreach (DataColumn destinationColumn in destinationTable.Columns)
{
string columnName = destinationColumn.ColumnName;
if (sourceTable.Columns.Contains(columnName))
{
destinationRow[columnName] = sourceRow[columnName];
}
}
}
您只是想添加_column_(意为具有相同名称和类型的列)或移动_data_从一个表到另一个表? – 2012-07-19 15:13:48
将数据从一个表移动到另一个表。 – 2012-07-19 15:14:28