Gets or sets a value indicating whether text in the text box is read-only.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
When this property is set to true, the contents of the control cannot be changed by the user at runtime. With this property set to true, you can still set the value of the Text property in code. You can use this feature instead of disabling the control with the Enabled property to allow the contents to be copied and ToolTips to be shown.