.NET Framework 4.6 and 4.5
Gets the total number of lines in the text box.
Public ReadOnly Property LineCount As Integer
Type: System.Int32The total number of lines in the text box, or –1 if layout information is not available.
If text wrapping is enabled, changing the width of the text box may change this value.
The value returned is the total number of lines in the text box, regardless of how many are currently visible.
Supported in: 4.6, 4.5, 4, 3.5, 3.0
.NET Framework Client Profile
Supported in: 4, 3.5 SP1