Lambda表达式中的Select语句出错

Question

我有以下代码:

getAllResult.GroupBy(g => g.OriginatingTransactionID)
.Select(r => 
{
    usp_GetAll_Result getAllResult1 = r.Select(x => x).FirstOrDefault();
    Bundle bundle = new Bundle
    {
        BundleName = getAllResult1.BundleName,
        BundleStatusCode = getAllResult1.BundleStatusCode,
        BundleStatusReasonCode = getAllResult1.BundleStatusReasonCode
    };
}).ToList();

编译时我收到错误:

无法从用法推断出方法'System.Linq.Enumerable.Select(System.Collections.Generic.IEnumerable,System.Func)'的类型参数.尝试显式指定类型参数.

Answer 1

.Select()返回一个值.目前,您没有从表达式返回任何内容.

只需退回您的捆绑

Bundle bundle = new Bundle
                {
                    BundleName = getAllResult1.BundleName,
                    BundleStatusCode = getAllResult1.BundleStatusCode,
                    BundleStatusReasonCode = getAllResult1.BundleStatusReasonCode
                };

return bundle;