Hi Prashanthi,
We are regret for the inconvenience caused.
By default, ChartSeries.Name will be displayed as a tooltip while mouse hover the histogram column. If your intention should be display the X-value tooltip for the Columns(bars) of Histogram Chart, currently we are not providing support for this.Only the Bubbles in Histogram chart having the X, Y values (Bubbles are DataPoints). So, the tooltip displays the correct X or Y value only for the Bubbles. If we removed the bubbles we can't expect the X or Y value tooltip. Columns in Histogram does not have X and Y value like Columns in Column Chart. So, we don't expect the X and Y value for the Columns in Histogram Chart.
To display custom text as tooltip user need to handle ChartControl_RegionMousehover event accordingly.
I have create simple sample to display the custom text(column index) tooltip to histogram columns. Please download it from the link below
HistogramToolTip1194195621.zipPlease let us know if you have any concerns.
Regards,
Vijayabharathi K