C#行列转换（交叉表）处理源代码

///

/// 将DataTable的第二列的值转化为列（即将原来的行表，转化成交叉表，没有对应值则默认0）贾世义
///

/// 必须三列，第三列为值
///
public static DataTable GetCrossTable(DataTable dt)
{
if (dt == null || dt.Columns.Count != 3 || dt.Rows.Count == 0)
{
return dt;
}
else
{
DataTable result = new DataTable();
result.Columns.Add(dt.Columns[0].ColumnName, dt.Columns[2].DataType);
DataTable dtColumns = dt.DefaultView.ToTable("dtColumns", true, dt.Columns[1].ColumnName);
foreach (DataRow drColumnsRow in dtColumns.Select("", dt.Columns[1].ColumnName))
{
string colName = GetValue(drColumnsRow[0]);
if (String.IsNullOrEmpty(colName))
{
colName = "无列名";
}
result.Columns.Add(colName);
result.Columns[result.Columns.Count - 1].DefaultValue = 0;
}
DataRow drNew = result.NewRow();
drNew[0] = dt.Rows[0][0];
string rowName = drNew[0].ToString();
foreach (DataRow dr in dt.Rows)
{
string colName = dr[1].ToString();
if (rowName.Equals(dr[0].ToString(), StringComparison.CurrentCultureIgnoreCase))
{
drNew[colName] = dr[2];
}
else
{
result.Rows.Add(drNew);
drNew = result.NewRow();
drNew[0] = dr[0];
rowName = drNew[0].ToString();
drNew[colName] = dr[2];
}
}
result.Rows.Add(drNew);
return result;
}
}