ExpressionExtensions
The extensions for Expression.
Методы
public static IQueryable[] EnumerateSources(Expression expression)result = ExpressionExtensions.EnumerateSources(expression)Lists every queryable source names: the one it is composed over plus any a join or a sub-query brings in.
- expression
- The composed query.
Возвращает: The distinct sources, in the order they appear.
public static object Evaluate(Expression e)result = ExpressionExtensions.Evaluate(e)Evaluates the expression and returns its value.
- e
- The expression to evaluate.
Возвращает: The evaluated value.
public static T GetConstant<T>(Expression e)result = ExpressionExtensions.GetConstant(e)Gets the constant value from the expression.
- e
- The expression.
Возвращает: The constant value.
public static MemberExpression GetInnerMember(MemberExpression exp)result = ExpressionExtensions.GetInnerMember(exp)Retrieves the innermost member in a nested member expression.
- exp
- The member expression to process.
Возвращает: The innermost member expression.
public static object GetMemberValue(MemberInfo member, object instance)result = ExpressionExtensions.GetMemberValue(member, instance)Gets the value of the specified member from the given instance.
- member
- The member whose value to retrieve.
- instance
- The object instance from which to retrieve the value.
Возвращает: The value of the member.
public static TValue GetValue<TValue>(Expression exp)result = ExpressionExtensions.GetValue(exp)Evaluates the expression and returns its value as the specified type.
- exp
- The expression to evaluate.
Возвращает: The evaluated value converted to the specified type.
public static Expression PinSources(Expression expression, IQueryable[] sources)result = ExpressionExtensions.PinSources(expression, sources)Rebuilds so that every source it names is held in place, and reports the sources found.
- expression
- The composed query.
- sources
- The distinct sources, in the order they appear.
Возвращает: The rebuilt expression, naming each source directly.
public static Expression ReplaceRootSource(Expression expression, IQueryable source)result = ExpressionExtensions.ReplaceRootSource(expression, source)Rebuilds over another source, so a query composed against one queryable runs against another.
- expression
- The composed query, e.g. a Where over a table.
- source
- The source to run it over instead, e.g. the same table held in memory.
Возвращает: The rebuilt expression, or when it has no queryable root.
public static void ReplaceSource(Expression expression, IQueryProvider provider)ExpressionExtensions.ReplaceSource(expression, provider)Replaces the source provider in the expression with the specified query provider.
- expression
- The expression to modify.
- provider
- The query provider to set.
public static Expression ReplaceSources(Expression expression, IReadOnlyDictionary<object, IQueryable> sources)result = ExpressionExtensions.ReplaceSources(expression, sources)Rebuilds with each source it names replaced by the one mapped to it, so a query composed over database tables runs over held copies of them instead.
- expression
- The composed query.
- sources
- What to put in place of each source.
Возвращает: The rebuilt expression.
public static Expression StripQuotes(Expression e)result = ExpressionExtensions.StripQuotes(e)Removes quote expressions from the given expression.
- e
- The expression to process.
Возвращает: The unquoted expression.
public static ComparisonOperator ToOperator(ExpressionType type)result = ExpressionExtensions.ToOperator(type)Converts the given expression type to its equivalent ComparisonOperator.
- type
- The expression type.
Возвращает: The corresponding ComparisonOperator.