Question

如果选中复选框chkAus：

if (chkAus.Checked)
                {
                    vAdvanceSearchResults  = (from t in vAdvanceSearchResults
                                    join imp in _bDataContext.Imprints on t.ImprintID equals imp.ID
                                    join cc in _bDataContext.CountryCodes on imp.CountryID equals cc.ID
                                    where cc.Code.Contains("AU")
                                    select t).Distinct();**
                }

如果选中chkAus和chkNz

if (chkNz.Checked && chkAus.Checked)
            {
                vAdvanceSearchResults = (from t in vAdvanceSearchResults
                                join imp in _bDataContext.Imprints on t.ImprintID equals imp.ID
                                join cc in _bDataContext.CountryCodes on imp.CountryID equals cc.ID
                                where cc.Code.Contains("AU") || cc.Code.Contains("NZ")
                                select t).Distinct();
            }

当检查复选框时，linq查询的条件会发生变化。

where cc.Code.Contains("AU") || cc.Code.Contains("NZ")

我有近10个复选框，并且陷入了如何编写这么多条件的问题。请帮忙。

例如，如果有 chkUS ：然后结合 chkAus，chkNz，chkUS 复选框，linq查询将会改变。

where cc.Code.Contains("AU") || cc.Code.Contains("NZ") || cc.Code.Contains("US")

Answer 1

将所有这些放入列表中，然后执行if list.contains（cc.Code）

var a = new List<string>(){"AU","NZ","US"};
var linq =  (from t in vAdvanceSearchResults
                                join imp in _bDataContext.Imprints on t.ImprintID equals imp.ID
                                join cc in _bDataContext.CountryCodes on imp.CountryID equals cc.ID
                                where a.Contains(cc.Code)
                                select t).Distinct();

Answer 2

首先创建所选复选框的列表。像这样。

var selectedCountries = new List<string>();
if (chkAus.Checked) selectedCountries.Add("AU");
if (chkNz.Checked) selectedCountries.Add("NZ");
if (chkUs.Checked) selectedCountries.Add("US");
//... And so on

然后修改您的linq查询以检查此列表是否包含代码，我的意思是反转比较是一个答案。确保删除此linq查询的条件。

vAdvanceSearchResults = (from t in vAdvanceSearchResults 
    join imp in _bDataContext.Imprints on t.ImprintID equals imp.ID 
    join cc in _bDataContext.CountryCodes on imp.CountryID equals cc.ID
    where  selectedCountries.Contains(cc.Code)
    select t).Distinct();

这将解决您的问题。

linq to sql query with checkboxes where condition combination

2 个答案: