I got the solution for first question
LegendDisplayMode.DataPointLabel; but reply for question 2 is still expecting.
Have one more question.
On X asis I have very big names(screen shot attched), datase column (FULL_NAME) which makes the charts unreadable, I want to show only first 15 chars only for display purpose, which I have stored in other column(FULL_NAME_TRIM).
How can I create the X axis with column FULL_NAME and only for display purpose I want to show FULL_NAME_TRIM.
Below code give display as FULL_NAME, what change I shall do to draw the X Asix with column FULL_NAMEm but to display FULL_NAME_TRIM
new ItemMapping("YAxis", DataPointMember.YValue));
new ItemMapping("FULL_NAME)", DataPointMember.XCategory));