能解释下union吗。。我看的好像是并集,能得到1以上值吗? 我现在能得出1个表数据了,要得到几个得用到三维数组了好麻烦。 DataTable T = new DataTable(); DataSet ds1 = new DataSet(); foreach (DataGridViewColumn dgvc in m_TV.Columns) { DataColumn dc = new DataColumn(); dc.ColumnName = dgvc.DataPropertyName; T.Columns.Add(dc); } foreach (ListViewItem it in m_list.SelectedItems) { DataTable DT = (it.Tag as DataTable); int i = 0; DT.TableName = "DT" + i.ToString(); i++; ds1.Tables.Add(DT); } for (int a = 0; a < m_list.SelectedItems.Count; a++){
foreach (DataRow tRow in ds1.Tables[a].Rows) { int i = 0; DataRow dr = T.NewRow(); foreach (DataColumn dc in T.Columns) { if (tRow[i].ToString() == "True" || tRow[i].ToString() == "False") { int j = 0; if (tRow[i].ToString() == "True") { j++; } dr[dc] = j; } else { dr[dc] = tRow[i]; } i++; } T.Rows.Add(dr); } }
dt1.AsEnumerable().Union(dt2.AsEnumerable())...
我现在能得出1个表数据了,要得到几个得用到三维数组了好麻烦。 DataTable T = new DataTable();
DataSet ds1 = new DataSet();
foreach (DataGridViewColumn dgvc in m_TV.Columns)
{
DataColumn dc = new DataColumn();
dc.ColumnName = dgvc.DataPropertyName;
T.Columns.Add(dc);
}
foreach (ListViewItem it in m_list.SelectedItems)
{
DataTable DT = (it.Tag as DataTable);
int i = 0;
DT.TableName = "DT" + i.ToString();
i++;
ds1.Tables.Add(DT);
}
for (int a = 0; a < m_list.SelectedItems.Count; a++){
foreach (DataRow tRow in ds1.Tables[a].Rows)
{
int i = 0;
DataRow dr = T.NewRow();
foreach (DataColumn dc in T.Columns)
{
if (tRow[i].ToString() == "True" || tRow[i].ToString() == "False")
{
int j = 0;
if (tRow[i].ToString() == "True")
{
j++;
}
dr[dc] = j;
} else
{
dr[dc] = tRow[i];
}
i++; }
T.Rows.Add(dr);
}
}