C# 列表上的动态查询选择包含列表
我正在尝试用c#创建一个动态过滤机制 我有一个用户类,它有名字、姓氏、生日等属性,还有UserInformations列表,它是UserInformation对象的列表。 UserInformation对象具有属性Id、名称和值。 和用户列表中的用户列表 我创建了一个UI来使用 它生成类似过滤器的C# 列表上的动态查询选择包含列表,c#,linq,query-builder,dynamicquery,C#,Linq,Query Builder,Dynamicquery,我正在尝试用c#创建一个动态过滤机制 我有一个用户类,它有名字、姓氏、生日等属性,还有UserInformations列表,它是UserInformation对象的列表。 UserInformation对象具有属性Id、名称和值。 和用户列表中的用户列表 我创建了一个UI来使用 它生成类似过滤器的 { "condition": "AND", "rules": [ { "id": "name", "field": "name", "type": "
{
"condition": "AND",
"rules": [
{
"id": "name",
"field": "name",
"type": "string",
"input": "text",
"operator": "equal",
"value": "huseyin"
},
{
"condition": "OR",
"rules": [
{
"id": "surname",
"field": "surname",
"type": "string",
"input": "text",
"operator": "equal",
"value": "34"
},
{
"id": "ix_2_Weight",
"field": "ix_2_Weight",
"type": "integer",
"input": "select",
"operator": "equal",
"value": 50
}
]
}
],
"valid": true
}
我对带有User属性的过滤器没有问题。但是,我正在尝试过滤UserInformations数组中的信息。
若字段名以ix开头并获取用户信息的id,则我将拆分字段名。但我找不到如何比较它的价值。
如果它是一个静态linq,它应该是
users.Where(u=>u.Informations.FirstOrDefault(i=>i.id==2/*id of information in filter*/)?.Value=="something"))
使用下面的代码调用过滤器
private async Task<List<User>> FilterUsers(FilterRule rule, List<UserFilterDto> users = null)
{
List<User> list = users ?? await GetUsersForFilter();
var tempList = list.BuildQuery(rule).ToList();
return tempList;
}
专用异步任务筛选器用户(筛选器规则,列表用户=null)
{
List List=用户??等待GetUsersForFilter();
var templast=list.BuildQuery(rule.ToList();
返回圣殿骑士;
}
动态查询部分如下
公共静态IQueryable构建查询(此IQueryable可查询,FilterRule FilterRule,out string parsedQuery,bool useIndexedProperty=false,string indexedPropertyName=null)
{
如果(filterRule==null)
{
parsedQuery=“”;
返回可查询;
}
var pe=Expression.Parameter(typeof(userdetaileddo),“item”);
var expressionTree=BuildExpressionTree(pe、filterRule、useIndexedProperty、indexedPropertyName);
if(expressionTree==null)
{
parsedQuery=“”;
返回可查询;
}
parsedQuery=expressionTree.ToString();
var whereCallExpression=Expression.Call(
类型(可查询),
“哪里”,
新[]{queryable.ElementType},
可查询的表达式,
Lambda(expressionTree,pe));
var filteredResults=queryable.Provider.CreateQuery(whereCallExpression);
返回筛选结果;
}
公共静态IQueryable构建查询(此IQueryable可查询,FilterRule FilterRule,out string parsedQuery,bool useIndexedProperty=false,string indexedPropertyName=null)
{
如果(filterRule==null)
{
parsedQuery=“”;
返回可查询;
}
var pe=Expression.Parameter(typeof(userdetaileddo),“item”);
var expressionTree=BuildExpressionTree(pe、filterRule、useIndexedProperty、indexedPropertyName);
if(expressionTree==null)
{
parsedQuery=“”;
返回可查询;
}
parsedQuery=expressionTree.ToString();
var whereCallExpression=Expression.Call(
类型(可查询),
“哪里”,
新[]{queryable.ElementType},
可查询的表达式,
Lambda(expressionTree,pe));
var filteredResults=queryable.Provider.CreateQuery(whereCallExpression);
返回筛选结果;
}
私有静态表达式BuildExpressionTree(ParameterExpression pe,FilterRule规则,bool useIndexedProperty=false,string indexedPropertyName=null)
{
if(rule.Rules!=null&&rule.Rules.Any())
{
变量表达式=
选择(childRule=>BuildExpressionTree(pe、childRule、useIndexedProperty、indexedPropertyName))
.Where(表达式=>表达式!=null)
.ToList();
var expressionTree=expressions.First();
var计数器=1;
while(计数器u => u.Informations.FirstOrDefault(i => i.id == 2)?.Value == "something"))
u => u.Informations.Any(i => i.id == 2 && i.Value == "something"))
private static Expression BuildCondition(FilterRule rule, Expression propertyExp)
{
Type type;
switch (rule.Type)
{
case "integer":
type = typeof(int);
break;
case "long":
type = typeof(long);
break;
case "double":
type = typeof(double);
break;
case "string":
type = typeof(string);
break;
case "date":
case "datetime":
type = typeof(DateTime);
break;
case "boolean":
type = typeof(bool);
break;
default:
throw new Exception($"Unexpected data type {rule.Type}");
}
Expression expression;
switch (rule.Operator.ToLower())
{
case "in":
expression = In(type, rule.Value, propertyExp);
break;
case "not_in":
expression = NotIn(type, rule.Value, propertyExp);
break;
case "equal":
expression = Equals(type, rule.Value, propertyExp);
break;
case "not_equal":
expression = NotEquals(type, rule.Value, propertyExp);
break;
case "between":
expression = Between(type, rule.Value, propertyExp);
break;
case "not_between":
expression = NotBetween(type, rule.Value, propertyExp);
break;
case "less":
expression = LessThan(type, rule.Value, propertyExp);
break;
case "less_or_equal":
expression = LessThanOrEqual(type, rule.Value, propertyExp);
break;
case "greater":
expression = GreaterThan(type, rule.Value, propertyExp);
break;
case "greater_or_equal":
expression = GreaterThanOrEqual(type, rule.Value, propertyExp);
break;
case "begins_with":
expression = BeginsWith(type, rule.Value, propertyExp);
break;
case "not_begins_with":
expression = NotBeginsWith(type, rule.Value, propertyExp);
break;
case "contains":
expression = Contains(type, rule.Value, propertyExp);
break;
case "not_contains":
expression = NotContains(type, rule.Value, propertyExp);
break;
case "ends_with":
expression = EndsWith(type, rule.Value, propertyExp);
break;
case "not_ends_with":
expression = NotEndsWith(type, rule.Value, propertyExp);
break;
case "is_empty":
expression = IsEmpty(propertyExp);
break;
case "is_not_empty":
expression = IsNotEmpty(propertyExp);
break;
case "is_null":
expression = IsNull(propertyExp);
break;
case "is_not_null":
expression = IsNotNull(propertyExp);
break;
default:
throw new Exception($"Unknown expression operator: {rule.Operator}");
}
return expression;
}
if (rule.Field.StartsWith("ix_"))
{
var tokens = rule.Field.Split("_");
var infoParameter = Expression.Parameter(typeof(UserInformation), "i");
var infoCondition = Expression.AndAlso(
Expression.Equal(
Expression.Property(infoParameter, nameof(UserInformation.Id)),
Expression.Constant(long.Parse(tokens[1]))),
BuildCondition(rule, Expression.Property(infoParameter, tokens[2])));
return Expression.Call(
typeof(Enumerable), nameof(Enumerable.Any), new[] { infoParameter.Type },
Expression.Property(pe, nameof(User.Informations)),
Expression.Lambda(infoCondition, infoParameter));
}