protected override void OnClick()
{
string tessPath = Environment.GetEnvironmentVariable(ArcStrabo2Extension.EnvironmentVariableTESS_DATA, EnvironmentVariableTarget.User);
if (!string.IsNullOrEmpty(tessPath))
{
ArcMap.Application.CurrentTool = null;
MessageBox.Show(tessPath);
}
else
MessageBox.Show(ArcStrabo2Extension.ErrorMsgNoTess_Data);
}