SharePoint 获取Lookup 字段的值

获取某个List里的Lookup字段的值是很普遍的事，那么我们将它封装起来

获取Lookup字段值的方法：

 1         /// <summary>
 2         /// To get lookup field Id or Value
 3         /// </summary>
 4         /// <typeparam name="T"></typeparam>
 5         /// <param name="item"></param>
 6         /// <param name="fieldName"></param>
 7         /// <param name="defaultValue"></param>
 8         /// <param name="getValueType">0:return Id, 1:return Value</param>
 9         /// <returns></returns>
10         public static T GetLookupField<T>(this SPListItem item, string fieldName, int getValueType, T defaultValue)
11         {
12             fieldName = fieldName.Replace(" ", ConstVariables.blankSpicalCode);
13 
14             if (item[fieldName] == null)
15             {
16                 return defaultValue;
17             }
18 
19             var itemElements = Regex.Split(item[fieldName].ToString(), ";#", RegexOptions.IgnoreCase);
20 
21             if (itemElements.Length >= 2)
22             {
23                 return ConvertTo<T>(itemElements[getValueType], defaultValue);
24             }
25             else
26             {
27                 return defaultValue;
28             }
29         }

调用该方法： <oldPlan是SPListItem>
1. 获取Lookup的ID:

oldPlan.GetLookupField<int>(ConstVariables.PRColumns.ColumnStatus, 0, 0);

2. 获取Lookup的Value:

oldPlan.GetLookupField<string>(ConstVariables.AllBGProfileColumns.ColumnBGName, 1, string.Empty)