What does the Tab Control's ContainsKey() method compare against?

I want to create a Tab Control that only opens content once. Each item that is opened needs to check the container to make sure it isn't already being displayed. I believe the method I want to use is the bool TabControl.TabPages.ContainsKey(string key) method, however it always returns a value of false.

I've created a work-around where I store the object in a separate list that I keep in sync with the tab control, but it feels very wrong. I have a list in the TabPages property of the control, so I should be able to query against it.

Am I missing a property? Is my expectation of this method and what it's performing correct? How do I get it to correctly identify my opened tabs?

Here is some sample code that is similar to what I'm doing:

private void _fillTabControl()
{
    List<string> keys = new List&l开发者_运维知识库t;string>() { "one", "two" };
    foreach (string key in keys)
        _addTab(key);

    bool alreadyOpened = tabControl.TabPages.ContainsKey(keys[0]);
}
private void _addTab(string key)
{
    TextBox textBox = new TextBox();
    textBox.Text = key;

    TabPage tab = new TabPage();
    tab.Text = key;

    tab.Controls.Add(textBox);
    tabControl.TabPages.Add(tab);
}

The doc says it all:

"The Name property corresponds to the key for a TabPage in the TabControl.TabPageCollection."

You're using the Text property, you should set

tab.Name = "MyName";

and then

tabControl.TabPages.ContainsKey("MyName");

will return true;