Question

I am having a dictionary which was defined as follows

Dictionary<int, List<int>> dict1 = new Dictionary<int, List<int>>();

I will have a list element where i can store the values which will come from database

List<int> lstdbTaskID = new List<int>();

assume this holds

100 105 110 200

respectively.

I will have my dictionary with values stored as follows. Assume that i have 2 keys 10,20 respectively, and for this key values i will have my values as for 10 i will have 100,105 and 110 and for 20 i will have 200.

I would like to compare these values with the list available lstdbTaskID

I tried this

foreach (int strlst in lstdbTaskID)
{
    if (dict1.ContainsValue(lstdbTaskID[strlst]))
}

But i am getting errors as follows

The best overloaded method match for ‘System.Collections.Generic.Dictionary>.ContainsValue(System.Collections.Generic.List)’ has some invalid arguments`

and

Cannot convert from ‘int’ to ‘System.Collections.Generic.List’`

can any help me on this?

Answer 1

Your code is wrong at because you are trying to compare int value with List of int.

Your dictionary is:
Dictionary of int to List of int.

and you have another structure as
List of int

so when you do:

// Compiler fails here because you are trying to check whether dictionary contains
// the given integer value. Dictionary in this case has a list of integers as its `Value` 
// in its `<Key,Value>` pair.
dict1.ContainsValue(lstdbTaskID[strlst])

Use linq statement:

foreach (int strlst in lstdbTaskID)
{
    if (dict1.Any(pair => pair.Value.Contains(strlst)))
    {
        // do something
    }
}

Edit: If you want this without linq, do the linq task by self.

foreach (int strlst in lstdbTaskID)
{
    foreach (int key in dict1.Keys)
    {
        if (dict1[key].Contains(strlst))
        {
            // do something
        }
    }
}