如何检查字典/集合是否可以迭代？

Question

I have some code that works on a dictionary and Using simple linq functions to find some key values within the dictionary however recently I am getting the following error ...

InvalidOperationException: Operation is not valid due to the current state of the object
System.Linq.Enumerable.Iterate[KeyValuePair`2,Int32] (IEnumerable`1 source, Int32 initValue, System.Func`3 selector)

How do I confirm that the operation is safe to be carried out and thus avoid this error?

Code sample causing the problem ...

public void UpdateBounds()
{
    lock (Voxels)
    {
            Start = new IntVector3(Voxels.Min(v => v.Key.X), Voxels.Min(v => v.Key.Y), Voxels.Min(v => v.Key.Z));
            End = new IntVector3(Voxels.Max(v => v.Key.X), Voxels.Max(v => v.Key.Y), Voxels.Max(v => v.Key.Z));
    }
}

Answer 1

Looks like you're doing an operation on an empty Dictionary object.

Check if it contains anything before executing that statement. Dictionary.Count is your guy.