IQueryable，如何處理特殊情況-有解無憂

我應該讓 IQueryable 處理以下特殊情況：

s => s.Trusting == searchTrusting
s => s.Trusted == searchTrusted
s => s.Trusting == searchTrusting and s => s.Trusted == searchTrusted
other cases

我應該如何提出指定這些情況的 IQueryable 請求。我以前從未使用過 IQueryable。

我的同事建議我使用：

var specialCases = IQueryable.
IQueryable.

他的評論是：這種方法只能部分解決問題嘗試結合 IQueryable 并為每種情況分開 if。

如何實作組合 IQueryable？

在他發表評論之前，ifs 處于 if、else if、else if、else 狀態為了獲得相同的結果，我使用了現有的解決方案：（它有效）

var domainTrustColl = _domainTrustRepository.GetDomainTrustItems().ToList().ConvertAll(new Converter<DomainTrustItem, DomainTrustModel>(DomainTrustModel.FromDomain));

domainTrustColl = domainTrustColl.Where(s => s.Trusting.Contains(searchTrusting)).Where(s => s.Trusted.Contains(searchTrusted)).Where(s => s.Type.Contains(searchType)).ToList();

            if (!string.IsNullOrEmpty(searchTrusting))
            {
                domainTrustColl = domainTrustColl.Where(s => s.Trusting == searchTrusting).Where(s => s.Trusted.Contains(searchTrusted)).Where(s => s.Type.Contains(searchType)).ToList();
            }
            if (!string.IsNullOrEmpty(searchTrusted))
            {
                domainTrustColl = domainTrustColl.Where(s => s.Trusting.Contains(searchTrusting)).Where(s => s.Trusted == searchTrusted).Where(s => s.Type.Contains(searchType)).ToList();
            }
            if (!string.IsNullOrEmpty(searchTrusting) && !string.IsNullOrEmpty(searchTrusted))
            {
                domainTrustColl = domainTrustColl.Where(s => s.Trusting == searchTrusting).Where(s => s.Trusted == searchTrusted).Where(s => s.Type.Contains(searchType)).ToList();
            }

uj5u.com熱心網友回復：

從您的 LINQ 查詢中，我看到這條陳述句是多余的

.Where(s => s.Type.Contains(searchType))

因此，您的IQueryable查詢可以簡化如下：

...

var query = domainTrustColl.Where(s => s.Type.Contains(searchType));

// Case - Both not selected
if (string.IsNullOrEmpty(searchTrusting) && string.IsNullOrEmpty(searchTrusted))
{
    // Handle no select any case
}
// Third case - Both selected
else if (!string.IsNullOrEmpty(searchTrusting) && !string.IsNullOrEmpty(searchTrusted))
{
    query = query.Where(s => s.Trusting == searchTrusting)
        .Where(s => s.Trusted == searchTrusted);
}
// First case
else if (!string.IsNullOrEmpty(searchTrusting))
{
    query = query.Where(s => s.Trusting == searchTrusting)
        .Where(s => s.Trusted.Contains(searchTrusted));
}
// Second case
else if (!string.IsNullOrEmpty(searchTrusted))
{
    query = query.Where(s => s.Trusting.Contains(searchTrusting))
        .Where(s => s.Trusted == searchTrusted);
}

domainTrustColl  = query.ToList();

最后，具體化查詢以通過.ToList().

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