What is the algorithm of TreeNode.Nodes.ContainsKey

Question

I am confused about TreeNode.Nodes.ContainsKey(string key) if its searching recursively in its childs for the key, or just searches in its childs only using a regular for loop.
If it recursively searches about the key, is there is a method to search only in its childs?

Answer 1

According to the Reference Source, ContainsKey does the following:

    public virtual bool ContainsKey(string key) {
       return IsValidIndex(IndexOfKey(key)); 
    }

And that method does:

    public virtual int  IndexOfKey(String key) {
        // Step 0 - Arg validation
        if (string.IsNullOrEmpty(key)){
            return -1; // we dont support empty or null keys.
        }

        // step 1 - check the last cached item
        if (IsValidIndex(lastAccessedIndex))
        {
            if (WindowsFormsUtils.SafeCompareStrings(this[lastAccessedIndex].Name, key, /* ignoreCase = */ true)) {
                return lastAccessedIndex;
            }
        }

        // step 2 - search for the item
        for (int i = 0; i < this.Count; i ++) {
            if (WindowsFormsUtils.SafeCompareStrings(this[i].Name, key, /* ignoreCase = */ true)) {
                lastAccessedIndex = i;
                return i;
            }
        }

        // step 3 - we didn't find it.  Invalidate the last accessed index and return -1.
        lastAccessedIndex = -1;
        return -1;
    }

    private bool IsValidIndex(int index) {
        return ((index >= 0) && (index < this.Count));
    }

So it appears it just tries to find the index for the key, and if it's valid then that means the key must exist.