Expression to filter data based on a property which is a list of strings
2
I have the following code:
case FilterQueryType.Contains:
var parameterExp = Expression.Parameter(type, "type");
var propertyExp = Expression.Property(parameterExp, filter.PropertyName);
var containsConstExp = Expression.Constant(filter.MyKeyword);
MethodInfo method = typeof(string).GetMethod("Contains", new {typeof(string)});
var containsMethodExp = Expression.Call(propertyExp, method, containsConstExp);
var containsLambda = Expression.Lambda<Func<T, bool>>(containsMethodExp, parameterExp);
items = items.Where(containsLambda);
break;
This code works fine as long as filter.PropertyName is a string.
Now I have a case where filter.PropertyName is actually an enumerable of strings.
Could someone tell me how can I create the correct expression for this? (filter.MyKeyword itself will always be a single value)
c# lambda expression
edited Nov 23 '18 at 8:33
Rob
2,90512351
asked Nov 23 '18 at 8:32
KaiKai
2871314
add a comment |
2
I have the following code:
case FilterQueryType.Contains:
var parameterExp = Expression.Parameter(type, "type");
var propertyExp = Expression.Property(parameterExp, filter.PropertyName);
var containsConstExp = Expression.Constant(filter.MyKeyword);
MethodInfo method = typeof(string).GetMethod("Contains", new {typeof(string)});
var containsMethodExp = Expression.Call(propertyExp, method, containsConstExp);
var containsLambda = Expression.Lambda<Func<T, bool>>(containsMethodExp, parameterExp);
items = items.Where(containsLambda);
break;
This code works fine as long as filter.PropertyName is a string.
Now I have a case where filter.PropertyName is actually an enumerable of strings.
Could someone tell me how can I create the correct expression for this? (filter.MyKeyword itself will always be a single value)
c# lambda expression
edited Nov 23 '18 at 8:33
Rob
2,90512351
asked Nov 23 '18 at 8:32
KaiKai
2871314
add a comment |
2
2
2
I have the following code:
case FilterQueryType.Contains:
var parameterExp = Expression.Parameter(type, "type");
var propertyExp = Expression.Property(parameterExp, filter.PropertyName);
var containsConstExp = Expression.Constant(filter.MyKeyword);
MethodInfo method = typeof(string).GetMethod("Contains", new {typeof(string)});
var containsMethodExp = Expression.Call(propertyExp, method, containsConstExp);
var containsLambda = Expression.Lambda<Func<T, bool>>(containsMethodExp, parameterExp);
items = items.Where(containsLambda);
break;
This code works fine as long as filter.PropertyName is a string.
Now I have a case where filter.PropertyName is actually an enumerable of strings.
Could someone tell me how can I create the correct expression for this? (filter.MyKeyword itself will always be a single value)
c# lambda expression
edited Nov 23 '18 at 8:33
Rob
2,90512351
asked Nov 23 '18 at 8:32
KaiKai
2871314
I have the following code:
case FilterQueryType.Contains:
var parameterExp = Expression.Parameter(type, "type");
var propertyExp = Expression.Property(parameterExp, filter.PropertyName);
var containsConstExp = Expression.Constant(filter.MyKeyword);
MethodInfo method = typeof(string).GetMethod("Contains", new {typeof(string)});
var containsMethodExp = Expression.Call(propertyExp, method, containsConstExp);
var containsLambda = Expression.Lambda<Func<T, bool>>(containsMethodExp, parameterExp);
items = items.Where(containsLambda);
break;
This code works fine as long as filter.PropertyName is a string.
Now I have a case where filter.PropertyName is actually an enumerable of strings.
Could someone tell me how can I create the correct expression for this? (filter.MyKeyword itself will always be a single value)
c# lambda expression
c# lambda expression
edited Nov 23 '18 at 8:33
Rob
2,90512351
asked Nov 23 '18 at 8:32
KaiKai
2871314
edited Nov 23 '18 at 8:33
Rob
2,90512351
asked Nov 23 '18 at 8:32
KaiKai
2871314
edited Nov 23 '18 at 8:33
Rob
2,90512351
edited Nov 23 '18 at 8:33
Rob
2,90512351
edited Nov 23 '18 at 8:33
Rob
2,90512351
2,90512351
asked Nov 23 '18 at 8:32
KaiKai
2871314
asked Nov 23 '18 at 8:32
KaiKai
2871314
asked Nov 23 '18 at 8:32
KaiKai
2871314
2871314
add a comment |
add a comment |
1 Answer
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MemberExpression memberExpression = Expression.Property(parameterExp, filter.PropertyName);
Expression convertExpression = Expression.Convert(memberExpression, typeof(List<string>));
MethodCallExpression containsExpression = Expression.Call(convertExpression, "Contains", new Type { }, constExpr);
lambda = Expression.Lambda<Func<T, bool>>(containsExpression, parameterExp);
items = items.Where(lambda);
This solution works for me
answered Nov 26 '18 at 7:24
KaiKai
2871314
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
0
MemberExpression memberExpression = Expression.Property(parameterExp, filter.PropertyName);
Expression convertExpression = Expression.Convert(memberExpression, typeof(List<string>));
MethodCallExpression containsExpression = Expression.Call(convertExpression, "Contains", new Type { }, constExpr);
lambda = Expression.Lambda<Func<T, bool>>(containsExpression, parameterExp);
items = items.Where(lambda);
This solution works for me
answered Nov 26 '18 at 7:24
KaiKai
2871314
add a comment |
0
MemberExpression memberExpression = Expression.Property(parameterExp, filter.PropertyName);
Expression convertExpression = Expression.Convert(memberExpression, typeof(List<string>));
MethodCallExpression containsExpression = Expression.Call(convertExpression, "Contains", new Type { }, constExpr);
lambda = Expression.Lambda<Func<T, bool>>(containsExpression, parameterExp);
items = items.Where(lambda);
This solution works for me
answered Nov 26 '18 at 7:24
KaiKai
2871314
add a comment |
0
0
0
MemberExpression memberExpression = Expression.Property(parameterExp, filter.PropertyName);
Expression convertExpression = Expression.Convert(memberExpression, typeof(List<string>));
MethodCallExpression containsExpression = Expression.Call(convertExpression, "Contains", new Type { }, constExpr);
lambda = Expression.Lambda<Func<T, bool>>(containsExpression, parameterExp);
items = items.Where(lambda);
This solution works for me
answered Nov 26 '18 at 7:24
KaiKai
2871314
MemberExpression memberExpression = Expression.Property(parameterExp, filter.PropertyName);
Expression convertExpression = Expression.Convert(memberExpression, typeof(List<string>));
MethodCallExpression containsExpression = Expression.Call(convertExpression, "Contains", new Type { }, constExpr);
lambda = Expression.Lambda<Func<T, bool>>(containsExpression, parameterExp);
items = items.Where(lambda);
This solution works for me
answered Nov 26 '18 at 7:24
KaiKai
2871314
answered Nov 26 '18 at 7:24
KaiKai
2871314
answered Nov 26 '18 at 7:24
KaiKai
2871314
answered Nov 26 '18 at 7:24
KaiKai
2871314
2871314
add a comment |
add a comment |
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