public static Expression <Func <T, bool> > Or <T>(
            this Expression <Func <T, bool> > one, Expression <Func <T, bool> > another)
        {
            var candidateExpr     = Expression.Parameter(typeof(T), "candidate");
            var parameterReplacer = new ParameterReplacer(candidateExpr);

            var left  = parameterReplacer.Replace(one.Body);
            var right = parameterReplacer.Replace(another.Body);
            var body  = Expression.Or(left, right);

            return(Expression.Lambda <Func <T, bool> >(body, candidateExpr));
        }
        public static Expression <Func <T, bool> > And <T>(this Expression <Func <T, bool> > one,
                                                           Expression <Func <T, bool> > another)
        {
            // 首先定义好一个ParameterExpression
            var candidateExpr     = Expression.Parameter(typeof(T), "candidate");
            var parameterReplacer = new ParameterReplacer(candidateExpr);

            // 将表达式树的参数统一替换成我们定义好的candidateExpr
            var left  = parameterReplacer.Replace(one.Body);
            var right = parameterReplacer.Replace(another.Body);

            var body = Expression.And(left, right);

            return(Expression.Lambda <Func <T, bool> >(body, candidateExpr));
        }
Beispiel #3
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        public FilterBuilder <TEntity> Or(Expression <Func <TEntity, bool> > expr)
        {
            if (_result == null)
            {
                _result = expr;
                return(this);
            }

            var candidateExpr     = Expression.Parameter(typeof(TEntity), "t");
            var parameterReplacer = new ParameterReplacer(candidateExpr);

            var left  = parameterReplacer.Replace(_result.Body);
            var right = parameterReplacer.Replace(expr.Body);
            var body  = Expression.Or(left, right);

            _result = Expression.Lambda <Func <TEntity, bool> >(body, candidateExpr);
            return(this);
        }
Beispiel #4
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        public FilterBuilder <TEntity> And(Expression <Func <TEntity, bool> > expr)
        {
            if (_result == null)
            {
                _result = expr;
                return(this);
            }
            // 首先定义好一个ParameterExpression
            var candidateExpr     = Expression.Parameter(typeof(TEntity), "t");
            var parameterReplacer = new ParameterReplacer(candidateExpr);

            // 将表达式树的参数统一替换成我们定义好的candidateExpr
            var left  = parameterReplacer.Replace(_result.Body);
            var right = parameterReplacer.Replace(expr.Body);

            var body = Expression.And(left, right);

            _result = Expression.Lambda <Func <TEntity, bool> >(body, candidateExpr);
            return(this);
        }