C# 为什么可以';我枚举X509Store.Certificates
考虑以下代码:C# 为什么可以';我枚举X509Store.Certificates,c#,linq,C#,Linq,考虑以下代码: using (X509Store store = new X509Store(StoreName.My, StoreLocation.LocalMachine)) { store.Open(OpenFlags.ReadOnly); foreach (var certificate in store.Certificates) { if (!string.IsNullOrWhiteSpace(certificate?.SubjectName
using (X509Store store = new X509Store(StoreName.My, StoreLocation.LocalMachine))
{
store.Open(OpenFlags.ReadOnly);
foreach (var certificate in store.Certificates)
{
if (!string.IsNullOrWhiteSpace(certificate?.SubjectName?.Name)
&& certificate.SubjectName.Name.StartsWith("CN=*.mysite.com"))
{
return certificate;
}
}
}
所以我可以清楚地循环检查证书,但是为什么我不能列举它们呢。为什么下面的代码会抛出编译错误
var cert = store.Certificates.FirstOrDefault(x =>
string.IsNullOrWhiteSpace(x?.SubjectName?.Name) &&
x.SubjectName.Name.StartsWith("CN=*.mysite.com"));
错误CS1061“X509Certificate2Collection”不包含“FirstOrDefault”的定义,并且找不到接受“X509Certificate2Collection”类型的第一个参数的可访问扩展方法“FirstOrDefault”(是否缺少using指令或程序集引用?)
您应该将其转换为能够使用它:
store.Certificates.OfType<X509Certificate2>().FirstOrDefault(x =>
string.IsNullOrWhiteSpace(x?.SubjectName?.Name) &&
x.SubjectName.Name.StartsWith("CN=*.mysite.com"));
store.Certificates.OfType().FirstOrDefault(x=>
string.IsNullOrWhiteSpace(x?.SubjectName?.Name)&&
x、 SubjectName.Name.StartsWith(“CN=*.mysite.com”);
store.Certificates.Cast()
将为您提供所需的IEnumerable
。X509Certificate2Collection
实现System.Collections.IList
(请注意缺少的泛型说明符),使用Certificates.OfType().FirstOrDefault(…)