TextBoxBase.GetCharFromPosition Method (Point)
Retrieves the character that is closest to the specified location within the control.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
If the location specified in the pt parameter is outside the client area of the control, the first character of the string closest to the point specified in pt is returned. You can use this method to determine which characters are located near a specific point within the control. You can then use this value to perform operations on the text at that location.
If the specified location in the pt parameter is located on the right side of the client area of the control, the last character of the string closest to the point specified in pt is returned.
Available since 2.0