我正在使用Exchange Web服务托管API和联系人数据。 我有如下代码,它是功能性的 ,但并不理想: web
foreach (Contact c in contactList) { string openItemUrl = "https://" + service.Url.Host + "/owa/" + c.WebClientReadFormQueryString; row = table.NewRow(); row["FileAs"] = c.FileAs; row["GivenName"] = c.GivenName; row["Surname"] = c.Surname; row["CompanyName"] = c.CompanyName; row["Link"] = openItemUrl; //home address try { row["HomeStreet"] = c.PhysicalAddresses[PhysicalAddressKey.Home].Street.ToString(); } catch (Exception e) { } try { row["HomeCity"] = c.PhysicalAddresses[PhysicalAddressKey.Home].City.ToString(); } catch (Exception e) { } try { row["HomeState"] = c.PhysicalAddresses[PhysicalAddressKey.Home].State.ToString(); } catch (Exception e) { } try { row["HomeZip"] = c.PhysicalAddresses[PhysicalAddressKey.Home].PostalCode.ToString(); } catch (Exception e) { } try { row["HomeCountry"] = c.PhysicalAddresses[PhysicalAddressKey.Home].CountryOrRegion.ToString(); } catch (Exception e) { } //and so on for all kinds of other contact-related fields... }
正如我所说,这段代码有效 。 若是可能的话,如今我想减小一点 。 spa
我找不到任何容许我在尝试访问它以前检查字典中是否存在密钥的方法,若是我尝试读取它(使用.ToString()
)而且它不存在则会出现异常抛出: code
500
给定的密钥不在字典中。 orm
我怎样才能重构这段代码以减小(尽管仍在运行)? ip
PhysicalAddressDictionary.TryGetValue get
public bool TryGetValue ( PhysicalAddressKey key, out PhysicalAddressEntry physicalAddress )
c.PhysicalAddresses
的类型是c.PhysicalAddresses
? 若是它是Dictionary<TKey,TValue>
,那么您可使用ContainsKey
方法。 webservice
您可使用ContainsKey
: string
if (dict.ContainsKey(key)) { ... }
或TryGetValue
: it
dict.TryGetValue(key, out value);
更新 :根据注释,这里的实际类不是IDictionary
而是PhysicalAddressDictionary
,所以方法是Contains
和TryGetValue
但它们以相同的方式工做。 io
用法示例:
PhysicalAddressEntry entry; PhysicalAddressKey key = c.PhysicalAddresses[PhysicalAddressKey.Home].Street; if (c.PhysicalAddresses.TryGetValue(key, out entry)) { row["HomeStreet"] = entry; }
更新2:这是工做代码(由提问者编译)
PhysicalAddressEntry entry; PhysicalAddressKey key = PhysicalAddressKey.Home; if (c.PhysicalAddresses.TryGetValue(key, out entry)) { if (entry.Street != null) { row["HomeStreet"] = entry.Street.ToString(); } }
...根据须要为每一个键重复内部条件。 每一个PhysicalAddressKey(Home,Work等)只执行一次TryGetValue。
这是我今天作的一些东西。 彷佛为我工做。 基本上,您覆盖基本命名空间中的Add方法以进行检查,而后调用base的Add方法以实际添加它。 但愿这对你有用
using System; using System.Collections.Generic; using System.Collections; namespace Main { internal partial class Dictionary<TKey, TValue> : System.Collections.Generic.Dictionary<TKey, TValue> { internal new virtual void Add(TKey key, TValue value) { if (!base.ContainsKey(key)) { base.Add(key, value); } } } internal partial class List<T> : System.Collections.Generic.List<T> { internal new virtual void Add(T item) { if (!base.Contains(item)) { base.Add(item); } } } public class Program { public static void Main() { Dictionary<int, string> dic = new Dictionary<int, string>(); dic.Add(1,"b"); dic.Add(1,"a"); dic.Add(2,"c"); dic.Add(1, "b"); dic.Add(1, "a"); dic.Add(2, "c"); string val = ""; dic.TryGetValue(1, out val); Console.WriteLine(val); Console.WriteLine(dic.Count.ToString()); List<string> lst = new List<string>(); lst.Add("b"); lst.Add("a"); lst.Add("c"); lst.Add("b"); lst.Add("a"); lst.Add("c"); Console.WriteLine(lst[2]); Console.WriteLine(lst.Count.ToString()); } } }
我使用一个字典,因为重复性和可能丢失的密钥,我很快拼凑了一个小方法:
private static string GetKey(IReadOnlyDictionary<string, string> dictValues, string keyValue) { return dictValues.ContainsKey(keyValue) ? dictValues[keyValue] : ""; }
打电话给:
var entry = GetKey(dictList,"KeyValue1");
完成工做。