ILegendInfo pLegendInfo = pFeatureLayer;
for (long i = 0; i <= pLegendInfo.LegendGroupCount - 1; i++) {
pLgendGroup = pLegendInfo.LegendGroup(i);
pLgendGroup.Visible = false;
}
pMxDocument.UpdateContents();
Dim pLegendInfo As ILegendInfo
Set pLegendInfo = pFeatureLayer
Dim pLgendGroup As ILegendGroup
pLgendGroup.Visible = False
Dim i As Long
For i = 0 To pLegendInfo.LegendGroupCount - 1
Set pLgendGroup = pLegendInfo.LegendGroup(i)
pLgendGroup.Visible = False
Next i
pMxDocument.UpdateContents