Why doesn't AutoSize property in Windows Form TextBox appear in IntelliSense

According into the specs (http://msdn.microsoft.com/en-us/library/k63c05yf.aspx)

Textboxes in Windows Forms should have an autosize property.

And it actually d开发者_运维百科oesn't break when you type in TextBox1.AutoSize = true. However, it doesn't seem to appear in the list of IntelliSense properties.

Why is this?

I have tried recompiling and it all compiles, but the textbox.autosize property never appears.

The AutoSize property for TextBox is always true, forced by the constructor. The property is hidden in the parent class (TextBoxBase) to avoid accidentally setting it to false. It has [Browsable(false)] to hide it in the property grid, [EditorBrowsable(EditorBrowsableState.Never)] to hide it in the IntelliSense popup window. You can change it however:

public partial class Form1 : Form {
    public Form1() {
        InitializeComponent();
        textBox1.AutoSize = false;
        textBox1.Height += 10;
    }
}

Yes, doesn't look great. Now you know why it is hidden.

The Control.AutoSize property (and its override in TextBoxBase) is declared with the following attribute:

[EditorBrowsable(EditorBrowsableState.Never)]

IntelliSense uses this property to decide not to show the property in the completions list.

(I don't know enough about Windows Forms to say why this property is marked not browsable.)