C# DataColumn.GetAutoIncrementValue方法代码示例

//.........这里部分代码省略.........
			XmlNodeList childList = tableNode.ChildNodes;
			for (int i = 0; i < childList.Count; i++) {
				XmlNode childNode = childList[i];

				// we are looping through elements only
				// Note : if an element is inferred as a table and has text, but also has child elements,
				// the text is ignored.
				if (childNode.NodeType != XmlNodeType.Element)
					continue;
				
				// Elements that have attributes are inferred as tables. 
				// Elements that have child elements are inferred as tables. 
				// Elements that repeat are inferred as a single table. 
				if (IsInferredAsTable(childNode)) {
					// child node inferred as table
					if (inferSchema) {
						// We need to create new column for the relation between the current
						// table and the new table we found (the child table).
						string newRelationColumnName = table.TableName + "_Id";
						if (!table.Columns.Contains(newRelationColumnName)) {
							DataColumn newRelationColumn = new DataColumn(newRelationColumnName, typeof(int));
							newRelationColumn.AllowDBNull = false;
							newRelationColumn.AutoIncrement = true;
							// we do not want to serialize this column so MappingType is Hidden.
							newRelationColumn.ColumnMapping = MappingType.Hidden;
							table.Columns.Add(newRelationColumn);
						}
						// Add a row to the new table we found.
						AddRowToTable(childNode, table.Columns[newRelationColumnName], inferSchema, fillRows);
					}
					else
						AddRowToTable(childNode, null, inferSchema, fillRows);
					
				}
				else {
					// Elements that have no attributes or child elements, and do not repeat, 
					// are inferred as columns.
					object val = null;
					if (childNode.FirstChild != null)
						val = childNode.FirstChild.Value;
					else
						val = "";
					if (table.Columns.Contains(childNode.LocalName))
						rowValue.Add(childNode.LocalName, val);
					else if (inferSchema) {
						table.Columns.Add(childNode.LocalName);
						rowValue.Add(childNode.LocalName, val);
					}
				}
						
			}

			// Column can be attribute of the table element.
			XmlAttributeCollection aCollection = tableNode.Attributes;
			for (int i = 0; i < aCollection.Count; i++) {
				XmlAttribute attr = aCollection[i];
				//the atrribute can be the namespace.
				if (attr.Prefix.Equals("xmlns"))
					table.Namespace = attr.Value;
				else { // the attribute is a column.
					if (!table.Columns.Contains(attr.LocalName)) {
						DataColumn col = table.Columns.Add(attr.LocalName);
						col.ColumnMapping = MappingType.Attribute;
					}
					table.Columns[attr.LocalName].Namespace = table.Namespace;

					rowValue.Add(attr.LocalName, attr.Value);
				}
			}

			// If the current table is a child table we need to add a new column for the relation
			// and add a new relation to the DataSet.
			if (relationColumn != null) {
				if (!table.Columns.Contains(relationColumn.ColumnName)) {
					DataColumn dc = new DataColumn(relationColumn.ColumnName, typeof(int));
					// we do not want to serialize this column so MappingType is Hidden.
					dc.ColumnMapping = MappingType.Hidden;
					table.Columns.Add(dc);
					// Convention of relation name is: ParentTableName_ChildTableName
					DataRelation dr = new DataRelation(relationColumn.Table.TableName + "_" + dc.Table.TableName, relationColumn, dc);
					dr.Nested = true;
					DSet.Relations.Add(dr);
					UniqueConstraint.SetAsPrimaryKey (dr.ParentTable.Constraints, dr.ParentKeyConstraint);
				}
				rowValue.Add (relationColumn.ColumnName, relationColumn.GetAutoIncrementValue());
			}

			// Create new row and add all values to the row.
			// then add it to the table.
			DataRow row = table.NewRow ();
					
			IDictionaryEnumerator enumerator = rowValue.GetEnumerator ();
			while (enumerator.MoveNext ()) {
				row [enumerator.Key.ToString ()] = StringToObject (table.Columns[enumerator.Key.ToString ()].DataType, enumerator.Value.ToString ());
			}

			if (fillRows)
				table.Rows.Add (row);
			
		}